identifier: Hooper, James Matthew <https://research.library.mun.ca/view/creator_az/Hooper=3AJames_Matthew=3A=3A.html>   (1990) Late Quaternary glacial and sea level history of the Bernier Bay area, Northwestern Baffin Island, N.W.T.  Masters thesis, Memorial University of Newfoundland.

abstract: During the 1988 field season data were gathered for an investigation of the glacial and sea level history of the Bemier Bay area, northwestern Baffin Island. Twenty-eight new radiocarbon dates were obtained on samples of marine shells and whalebone. The dates indicate that the area was deglaciated by about 8200 BP by ice receding toward the east. Marine limit in the field area is approximately 120 m asl and decreases in age towards the east. Dates on whalebone collected from raised beaches have been used to construct three emergence curves. The curves show an exponential decline in the rate of postglacial emergence from an eariy Holocene maximum. The radiocarbon dates and geomorphic evidence are consistent with the interpretation that the bay was occupied by a large ice stream which flowed westward from the Foxe Dome. Prior to the Cockbum Phase (8000- 9000 BP), the ice tongue uncoupled from the seabed to form an extensive ice shelf. Large lateral moraines along the north and south coasts of the bay, deposited during this interval, have a near horizontal profile indicating deposition by an ice shelf rather than grounded ice. An independent ice cap was also present on southern Brodeur Peninsula during this interval.


identifier: Finn, Gregory Clement <https://research.library.mun.ca/view/creator_az/Finn=3AGregory_Clement=3A=3A.html>   (1988) Geochemical and isotopic evolution of the Maggo Gneiss component from the Hopedale Block, Labrador: evidence for Late-Middle Archaean crustal reworking.  Doctoral (PhD) thesis, Memorial University of Newfoundland.

type: Thesis NonPeerReviewed

format: application/pdf application/pdf

abstract: The Hopedale Block, an informal name for the southern portion of the Nain Structural province, Labrador, preserves evidence of a protracted Archaean to Proterozoic developmental history. This study examines the Archaean development of a segment of the Hopedale block, centered at Hopedale village as recorded in the Maggo gneiss, a typical grey gneiss of tonalitic to trondhjemitic composition. Following field mapping and petrographic examination of all lithologies within the study area, major, trace and rare earth element (REE) lithogeochemical analyses and Rb-Sr isotopic determinations were completed on the Maggo gneiss. -- The geochronological development of the Maggo gneiss, based on the Rb-Sr isotopic studies of twelve suites, identified three distinct Archaean tectonothermal events. Isotopic evidence of the oldest event, the Pre-Hopedalian, dated at 3306 +/- 75 Ma (1 sigma) is preserved at one locality; however structural evidence of this event can be recognized throughout the study area. Inclusions of supracrustal material (Weekes association) and anorthosite within Maggo gneiss, preserve evidence of two periods of deformation prior to the Pre-Hopedalian event. The dominant component of the Maggo gneiss is preserved within the Hopedalian domain. Four sample suites yielding ages of 3,140 +/- 95 Ma to 3,025 +/- 165 Ma date this event. The Hopedalian event produced moderate to steeply dipping NW-SE planar fabric within the gneiss. The Hopedale dykes, which predate the Hopedalian event were rotated into concordance with the Hopedalian fabric at this time. -- The Fiordian, a series of events, which marks the last major Archaean period of tectonism to affect the Hopedale Block lithologies, occurred between 2,927 +/- 50 Ma and 2,632 +/- 285 Ma. The Fiordian is divided into an early and late period characterized by reworking of preexisting crustal material separated by a period during which the Kanairiktok intrusive suite was emplaced. In response to the Fiordian reworking the Maggo gneiss exhibits the following characteristics:  -- 1) reorientation of earlier fabrics into a NE-SW direction,  -- 2) low to middle amphibolite facies metamorphism which retrogresses Hopedalian middle to upper amphibolite facies assemblages,  -- 3) large ion lithophile element (LILE; Rb, Ba, K) depletion, high field strength (HFS) element (TI, Zr, P, Y and V) enrichment and no change in either Sr or REE contents,  -- 4) resetting of the Rb-Sr isotopic systematics of the gneiss in response to Rb depletion. -- Geochemical reworking associated with the Fiordian event occurs independently of structural reworking. -- The application of the concept of areals and areal isochrones as applied to the Hopedalian and Fiordian suites yields ages of 3,366 +/- 212 Ma and 2,930 +/- 82 Ma, respectively. These ages date the timing for a common period of Sr homogenization for each group of suites at a specific point in their past. -- Petrogenetic modelling, using LILE, REE and HFS element and a variety of possible lithologic compositions has been carried out to determine the source to the Maggo gneiss precursor. An intermediate composition parent, metamorphosed to granulite and/or amphibolite facies, on 25% melting will yield REE and HFS element abundances in agreement with those observed for the Maggo gneiss. The source compositions modelled all require trace amounts (<0.5%) of minor, residual, phases, e.g. apatite, titanite and zircon, which control single elements, e.g. P, Ti and Zr respectively, and REE abundances in the resulting melts.  The major and trace element composition of the parent used is comparable to published results for Early Archaean crust as represented by the Amitsoq gneiss of southern West Greenland. -- These results extend the history of the Hopedale Block beyond that presently recognized. A proposed correlation between the recorded development for other areas of the North Atlantic Craton (NAC) and the Hopedale Block is presented.


identifier: Dunning, Gregory Ralph <https://research.library.mun.ca/view/creator_az/Dunning=3AGregory_Ralph=3A=3A.html>   (1984) The geology, geochemistry, geochronology and regional setting of the Annieopsquotch Complex and related rocks of southwest Newfoundland.  Doctoral (PhD) thesis, Memorial University of Newfoundland.

abstract: The Annieopsquotch Complex is an ophiolite which forms the Annieopsquotch Mountains of southwest Newfoundland. It contains rocks of the critical zone, gabbro zone (2.3 km thick), sheeted dyke zone (1.5 cm) and pillow lava zone of a typical ophiolite. The zones trend northeast, face and dip southeast at approximately fifty to seventy degrees and are offset by faults. -- Cumulate rocks of the critical zone preserve graded layers, trough structures and slump folds and elsewhere are metamorphosed and deformed. The gabbro zone is heterogeneous and contains many textural varieties of gabbro, pegmatitic pods, layering, trondhjemite pods and amphibolite near the base. It passes through a transition zone to a sheeted dyke zone which extends the full length of the ophiolite. Dykes trend northwest and are aphyric or plagioclase-phyric diabase. The pillow lava zone, besides pillow basalt, contains minor pillow breccia, hyaloclastite and chert. -- Major, trace and rare earth element geochemistry and clinopyroxene chemistry indicate that the suite is most similar to Normal-typ mid-ocean ridge basalt, low Zr contents being the only unusual feature. Trondhjemites have variable chemistry but elevated contents of trace elements consistent with differentiation from this basalt. -- The Annieopsquotch Complex is faulted against an Ordovician tonalite terrane to the northwest across the Lloyds River fault and against the Victoria Lake Group to the southeast. It is cut by dykes and sills correlated with both these units. The ophiolite is cut by two late Ordovician gabbro-diorite intrusions and a granite intrusion of presumed Devonian age and is unconformably overlain by early Silurian terrestrial sedimentary and volcanic rocks.  --  Two U-Pb ages for zircon from trondhjemite (477.5, 481.4 Ma) indicate that formation of the Annieopsquotch Complex occurred in Arenigian time. Zircon ages for the Bay of Islands (485.7 Ma) and Betts Cove Complexes (488.6 Ma) show them to be time equivalents, likewise Arenigian, refuting previous interpretations. A survey of ages of other ophiolites suggests that only oceanic crust (s.l.) formed over a limited time range is preserved in the Appalachian-Caledonian Mountain Belt. -- Other ophiolitic fragments, most intruded by or included in the tonalite, are preserved in a belt from Shanadithit Brook to King George IV Lake. Because of lithologic and chemical similarities, they are included in the Annieopsquotch ophiolite belt. Basalts of the Victoria Lake Group also have very similar chemistry suggesting a genetic link. Common orientations of sheeted dykes in the fragments suggest that they may have comprised one allochthon of Iapetus oceanic crust. This allochthon was emplaced over the Ordovician continental margin of North America during the Taconic Orogeny and intruded by tonalitic melts at that time.


identifier: Buchanan, Christopher R. <https://research.library.mun.ca/view/creator_az/Buchanan=3AChristopher_R=2E=3A=3A.html>   (2004) Structural architecture and evolution of the Humber Arm Allochthon, Frenchman's Cove - York Harbour, Bay of Islands, Newfoundland.  Masters thesis, Memorial University of Newfoundland.

abstract: The Frenchman's Cove -York Harbour area provides extensive exposure of a critical structural contact within the Humber Arm Allochthon. The Blow Me Down Ophiolite Massif is exposed in the uppermost structural slice and complexly deformed and dismembered sedimentary rocks of the Humber Arm Supergroup are located in the intermediate slices of the allochthon. The sedimentary rocks are early Cambrian- to early Ordovician-age and represent diverse depositional settings, including early rift-basins, the continental slope of the Cambro-Ordovician carbonate platform, and syntectonic flysch deposits. -- Five tectono-stratigraphic domains are distinguished on the basis of lithostratigraphy, the geometries of fold-thrust systems, and overprinting criteria of successive generations of structures. Detailed analysis of the fold-fault systems demonstrates that four phases of deformation affect the area. D₁ forms recumbent F₁ folds and duplex structures, creating regional scale nappe-type structures. A regional scale F₂ antiformal culmination at Frenchman's Cove is associated with thrust faults that dismember folded F₁ duplex structures during D₂. Out-of-sequence D₃ fault systems, truncate the antiformal culmination and incorporate slices of volcanic rocks in an east- verging imbricate fan, and locally form discreet melange zones. D₄ consists of a steep northerly-striking fault system with apparent sinistral strike-slip fault displacements. The complex structural systems mapped in this area demonstrate that careful, detailed tectono-stratigraphic studies are required to resolve the tectonic history of the allochthon and emplacement mechanisms of the Bay of Islands Ophiolite Complex.


identifier: Szybinski, Zbigniew Adam <https://research.library.mun.ca/view/creator_az/Szybinski=3AZbigniew_Adam=3A=3A.html>   (1995) Paleotectonic and structural setting of the western Notre Dame Bay area, Newfoundland Appalachians.  PhD thesis, Memorial University of Newfoundland.

abstract: The Appalachian Orogen in Newfoundland records the birth and destruction of the Iapetus Ocean. The Dunnage Zone preserves remnants of the oceanic terranes, and is subdivided into the western (Laurentian) Notre Dame Subzone and the eastern (Gondwanan) Exploits Subzone. This focus of this thesis has been to determine the geologic history of the northernmost part of the Notre Dame Subzone, confined between the Green Bay and Lobster Cove Faults. -- The geological history of the western Notre Dame Bay area has been investigated using field, geochemical, geochronological and structural methods. Care was taken to integrate the results obtained from these diverse methods in order to obtain an internally consistent model. As a result of these studies a new stratigraphic order is proposed, a major nappe has been recognized, and the character and tectonic history of one of the oldest intraoceanic sequences in the Notre Dame Subzone of the Newfoundland Appalachians has been determined. -- In simple terms, the geological history of the western Notre Dame Bay area can be described as follows: (1) a pre-500 Ma intraoceanic arc/back-arc stage, which involves deposition of the Lushs Bight Group and the lower part of the Western Arm Group (Sugar Loaves Basalt, Skeleton Pond Formation, and Big Hill Basalt); (2) emplacement of the pre-500 Ma sequence on the Laurentian continental margin and intrusion by high-Mg dykes of sanukitoid/bajaite affinities at 495 Ma; (3) development of a calc-alkalic arc (Cutwell Group and the upper two formations, Welsh Cove and Western Head, of the Western Arm Group) from 485 to 465 Ma, which is dominantly submarine, but whose chemistry is variably influenced by inputs from continental lithospheric sources; (4) development of a major alpine style fold nappe and its southeasterly directed emplacement (Notre Dame Bay Nappe) in the post-lower Silurian; and (5) post-emplacement structural disruption of the nappe, probably in the post-lower Carboniferous.


identifier: Young, Jennifer Leigh <https://research.library.mun.ca/view/creator_az/Young=3AJennifer_Leigh=3A=3A.html>   (2005) The stratigraphy and structrural history of the Mesozoic and Cenozoic of the Central Nova Scotian Slope, Eastern Canada.  Masters thesis, Memorial University of Newfoundland.

abstract: The continental shelf and slope of Nova Scotia is underlain by a number of interconnected rift sub-basins that collectively form the Scotian Basin. Petroleum exploration companies have been moderately successful on the shelf region of the basin, close to Sable Island, where several significant hydrocarbon discoveries have lead to the development of the Sable Project. This success has sparked interest in exploration of the adjacent frontier slope region within water depths between 200 and 2500m. However, the Scotian Slope Basin has been the focus of only limited regional geologic studies. Present accounts of the slope are largely extrapolated from shelf descriptions and/or modeled after play types and depositional systems typically associated with deep water exploration in other Atlantic margin areas. A discrete study area was defined for this project within the central slope region approximately 125 kilometres southwest of Sable Island. The area is approximately 120 square kilometres and contains five of the ten Scotian Slope exploration wells, three shelf wells and 4 500 kilometres of 2D seismic data. -- Scotian Basin development commenced in the Late Triassic - Early Jurassic with rifting of the Pangean Supercontinent and opening of the Atlantic Ocean. Red bed and evaporate deposition characterized the rift phase, while the drift phase was characterized by clastic progradational with periods of carbonate deposition. A prominent carbonate bank developed in the western part of the basin during the Late Jurassic, the eastern extent of which was limited by a Late Jurassic - Early Cretaceous Sable Delta. As relative sea level rose throughout the Late Cretaceous and Tertiary major transgressive sequences were deposited. This overall transgression was punctuated by major sea level drops resulting in the deposition of regressive lowstand sequences partially comprising turbidite deposits. -- Seismic stratigraphic analysis of the study area identified ten major sequence boundaries on the basis of reflection character and termination patterns. The sequence boundaries divide the Mesozoic through Cenozoic Scotian Slope Basin fill into nine depositional sequences. There are major changes in depositional style and thickness distribution patterns of the depositional sequence through time. Depositional patterns are closely linked to the tectonic, structural and halotectonic evolution of the basin. -- Five fault families were defined within the study on the basis of their regionality, duration of movement and depths of detachment; the Slope Basin-Bounding Fault Family, the Basement-Involved Fault Family, the Listric Growth Fault Family, the Major and Minor Sedimentary Fault Family and the Halokinetically Induced Fault Family. The existence of a sixth fault family, the Transfer Fault Family, is implied by local structural and stratigraphic architecture, however, the signature of this potential transfer fault is not clear enough on the available seismic data to allow for confident mapping. -- The complete spectrum of salt structures typical of passive margins has been identified and mapped within the study area. Five halotectonic structural associations with variable areal distributions have been identified. These associations are: the Trough and Swell Association, the Intra-Salt Detachment Association, the Diapiric Association, the Secondary Weld Association, and the Allochthonous Salt Association. -- The integration of seismic stratigraphic, structural and halotectonic analysis of the study area allowed for several conclusions regarding implications of a potential Scotian Slope petroleum system to be proposed. Considering all the elements and processes necessary for working hydrocarbon system, the most likely plays within the mapped study area consist of: 1) a reservoir of Cretaceous to Tertiary turbidite channel, levee or lobe sands, 2) a source rock most likely within the Kimmeridgian Verrill Canyon Formation (possible contribution from Jurassic Mohican Formation or Late Triassic to Early Jurassic early Syn-rift and/or Post-rift Lacustrine deposits, 3) a seal of Verrill Canyon Formation, Dawson Canyon or Banquereau shale or allochthonous salt, and 4) structural, tectonic and/or halokinetic traps ranging from Triassic to Cretaceous in age. -- Failure to discover hydrocarbons in recent slope explorations wells may point to the limitations of seismic resolution to predict reservoirs within the late Jurassic-Early Cretaceous successions. It also shows that drilling on the Scotian Slope is high risk exploration; more regional and better correlation of seismic with lithologies encountered in the wells are needed.


identifier: Voordouw, Ronald Jaap <https://research.library.mun.ca/view/creator_az/Voordouw=3ARonald_Jaap=3A=3A.html>   (2006) Geology of Mesoproterozoic anorthosite intrusions in the vicinity of Nain, Labrador.  Doctoral (PhD) thesis, Memorial University of Newfoundland.

abstract: This thesis investigates aspects of the 'anorthosite problem' through geological mapping and petrographic study of Proterozoic anorthositic rocks in the Nain batholith (NB), Labrador. The aspects of this problem to be investigated include the tectonomagmatic setting of this batholith, and the controls on ascent, emplacement and crystallization of the anorthositic rocks. Secondary emphasis is placed on the mineral and whole rock chemical evolution of these anorthositic rocks over time. Brief descriptions of Mesoproterozoic gabbronoritic, Fe-rich gabbroic, Fe-rich dioritic rocks and granitoid rocks that are spatially associated with anorthositic rocks are also presented, as well as descriptions of Paleoproterozoic and Archean country rock. -- The main findings of the thesis are based on 1:20 000 scale geological mapping over a 400 km² area that was previously covered only at reconnaissance scale. This area comprises four belts of Paleoproterozoic and/or Archean country rock and three Mesoproterozoic 'centered intrusive complexes'. These intrusive complexes are here referred to as 'centered' because each consists of a 'core' that is enveloped by a 'margin'. The core is sub-horizontally oriented and consists of anorthositic rocks, whereas the margin is sub-vertically oriented and consists of anorthositic, gabbronoritic +/- monzonitic, troctolitic and Fe-rich gabbroic rocks. The centered intrusive complexes in the study area are referred to as Tikkoatokak, Sophie and Kikkertavak. -- The four belts of country rock are here referred to as the Anaktalik Brook, Kangilialuk Lake, Nain Hill and Kauk Harbor country rock belts. Each of these belts contains gneiss and granulite that is of Paleoproterozoic +/- Archean age and structures that strike parallel to Paleoproterozoic structures of the Tomgat orogen. Compositional layering in the Nain Hill country rock belt shows an arcuate strike that is interpreted as a Paleoproterozoic structure that was rotated into a Mesoproterozoic east-west shear zone. This Mesoproterozoic shear zone was active during emplacement of the Nain batholith. This interpretation contrasts with previous work that suggested the arcuate strike was formed by a pre-Mesoproterozoic episode of folding or by the intrusion of Mesoproterozoic anorthositic rocks. -- The margins of all intrusive complexes in the study area were deformed in subvertical, north-south striking, shear zones and/or sub-vertical, east-west striking, shear zones. Field relations and compiled U-Pb ages indicate that this deformation was synchronous with emplacement of the Nain batholith (1365-1270 Ma). Map compilation is used to show that these shear zones continue north of the study area. Field relations of strongly and weakly deformed plutonic rocks in these shear zones indicate that Mesoproterozoic deformation on individual shear zones was episodic, which is consistent with new and compiled U-Pb ages that show north-south deformation occurred between 1351 and 1313 Ma and east-west deformation occurred between 1340 and 1311 Ma. -- Mesoproterozoic plutonic rocks in the study area were deformed in Mesoproterozoic north-south and east-west shear zones. The north-south striking shear zones lie adjacent to and strike parallel to Paleoproterozoic structures in the country rock, and it is suggested that the shear zones developed on re-activated Paleoproterozoic structures. The east-west striking shear zones strike parallel to the orientation of Mesoproterozoic faults in the Gardar Province of western Greenland, which comprised part of Mesoproterozoic Laurentia with the rocks in the study area. In addition to previous work on the tectono-magmatic setting of the Nain batholith, the findings indicate that emplacement of this batholith was contemporaneous with: (a) development of north-south shear zones, (b) development of east-west shear zones, (c) lithospheric thinning, graben development, and (d) back-arc extension. These findings are in contrasts to a mantle plume-related setting that has been proposed for petrogenesis of the Nain batholith. -- The margins of Mesoproterozoic intrusive complexes in the study area are: (a) composite, (b) bound by shear zones, (c) elongate parallel to shear zones, (d) are structurally controlled at shear zone intersections, and (e) contain xenoliths of strongly deformed plutonic rocks. These features are all characteristic of shear zone assisted melt transport and emplacement. These findings contrast with the widely held belief that the emplacement of anorthositic magmas is diapiric, and suggests a liquid-state rheology for anorthositic magmas during ascent and emplacement. -- The Tikkoatokak centered intrusive complex contains the oldest plutonic rocks in the study area. This intrusion shows a sub-rectangular and bell-jar form that suggests emplacement into a ductile crust that was controlled by sub-vertical and north-south striking shear zones. The northwestern part of the Kikkertavak centered intrusive complex contains the youngest plutonic rocks in the study area. This intrusion shows a sub-rectangular and convex down form that suggests emplacement into a dilating brittle crust that was controlled by steeply dipping, east-west striking, shear zones. The Sophie centered intrusive complex is intermediate in age with respect to the Tikkoatokak and NW Kikkertavak: centered intrusive complexes and contains plutonic rocks that were deformed in both north-south and east-west shear zones. These findings suggest that over the time span that covers emplacement of the Tikkoatokak: (> 13.33 Ma), Sophie and NW Kikkertavak: (between 1318 and 1311 Ma) centered intrusive complexes, the rheology of the crust changed from ductile to brittle and the structural controls on emplacement changed from north-south to east-west shear zones. These findings contrast with previous studies that suggested crustal uplift occurred in the waning stages (<1290 Ma) of emplacement of the Nain batholith. -- Anorthositic rocks in the study area show granular and/or poikilitic textures and microstructures that indicate high-T deformation and/or recrystallization. In addition, anorthositic rocks show relatively high variation in whole rock Mg/(Mg+Fe) in comparison to the range in normative plagioclase compositions, and are cut by ferrodiorite dikes that show sharp to gradational contacts. These characteristics are used to suggest that the crystallization of anorthositic magmas involved the formation of crystal frameworks and the compaction of these frameworks. Compaction may have been related to tectonic activity on the same shear zones that controlled the ascent and emplacement of magmas into intrusive complexes. It is suggested that this compaction also formed mottled rocks, primary layering and foliated rocks. In addition, compaction may also have produced planar aggregates of pyroxene crystals, calcic rims on plagioclase crystals and elevated wt% Al₂O₃ in the orthopyroxenes of anorthositic rocks. These findings indicate that the textures and structures in anorthositic rocks were produced in magmas that exhibited solid-state rheology and contrasts with previous work that suggests liquid-state processes (convection, crystal sedimentation) formed textures and structures during the crystallization of anorthositic magmas. -- Anorthositic rocks in the Tikkoatokak centered intrusive complex contain high abundances of Na-rich plagioclase, wt% K₂O, ppm Ba and ppm Sr in comparison to anorthositic rocks in the Sophie and Kikkertavak centered intrusive complexes. In contrast, the Sophie and Kikkertavak centered intrusive complexes contain high wt% CaO and Mg/(Fe+Mg). All anorthositic and gabbronoritic rocks in the Tikkoatokak centered intrusion lack olivine, whereas minor abundances of anorthositic and/or gabbronoritic rocks in the Sophie and NW Kikkertavak centered intrusive complexes contain olivine. These findings indicate that relatively Na-, K-, Ba- and Sr-rich anorthositic rocks were emplaced prior to Ca-rich, high Mg/(Fe+Mg) +/-olivine-bearing anorthositic rocks. These characteristics are used to suggest that anorthositic rocks with a greater crustal component  were emplaced prior to anorthositic rocks with a lower crustal component. -- Mineral and whole rock chemistry of anorthositic rocks from this study were compared to previous mineral chemistry, whole rock chemistry and geochronology studies. The mineral and whole rock chemistry characteristics of NB noritic anorthosite and NB troctolitic anorthosite are summarized, and follow a sub-division presented by Xue and Morse (1993). The result of this compilation is used to divide emplacement of the Nain batholith into four episodes. Episode 1 (1365 - 1330 Ma) involved the emplacement of NB noritic anorthosite and episode 2 (1330 - 1310 Ma) involved the emplacement of NB troctolitic anorthosite +/- NB noritic anorthosite. Episode 3 (1310 - 1290) involved the emplacement of troctolitic rocks in the northeastern part of the Nain batholith and emplacement of anorthositic and granitic rocks in the southern part of the Nain batholith. Episode 4 (1290 - 1270 Ma) involved the emplacement of peralkaline volcanic rocks and basaltic dikes. -- This study shows that anorthositic rocks in a Proterozoic batholith were generated and emplaced during a localized period of tectonic activity. This activity was accommodated on sub-vertically oriented and north-south, or east-west, striking shear zones, which also controlled the transport and emplacement of the magmas. The magmas that formed anorthosite were likely 'leucogabbroic' (65-90% plagioclase, 10-35% pyroxene + olivine + Fe-Ti oxide) in composition, and the crystallization of anorthosite from such magmas involved compaction and the removal of interstitial liquid. These findings suggest a positive correlation between tectonic activity and the petrogenesis of Proterozoic batholiths with anorthositic rocks, and it is hoped that this study will inspire further research of this correlation.


identifier: Edwards, Stephen John <https://research.library.mun.ca/view/creator_az/Edwards=3AStephen_John=3A=3A.html>   (1991) Magmatic and fluid processes in the Upper Mantle: a study of the Bay of Islands ophiolite complex, Newfoundland.  Doctoral (PhD) thesis, Memorial University of Newfoundland.

abstract: An extremely heterogeneous section of upper mantle exposed over 2 km² in the Springers Hill area of the Lewis Hills Massif, Bay of Islands Ophiolite Complex, consists of two distinct associations: low-Al peridotites and pyroxenites (LALPP), and high-Al peridotites, pyroxenites and gabbros (HALPPG). These represent the processes of magma and fluid generation, migration and evolution in the mantle wedge of a subduction zone. -- The LALPP have Cr-spinel of Cr# = 47-90, Mg# = 23-65, and fo-med in the order of harzburgite-orthopyroxenite (and associated dunite and chromititel-clinopyroxenite (and associated dunite, chromitite and websterite). Harzburgite is a refractory residue from partial melting and complete removal of low-Ti tholeiitic magma. This harzburgite has straight, positively sloping chondrite-normalized REE patterns and Pd/lr < 1. Dykes of orthopyroxenite have U-shaped chondrite-normalized PEE patterns and very high Pd/lr ratios, and formed from hydrous. As-saturated magma of boninitic affinity, which previously had fractionated significant quantities of Cr-spinel and relatively minor olivine. By mechanical mixing or magmatic impregnation, a component of orthopyroxenite was added to some harzburgites; these harzburgites have U-shaped chondrite-normalized REE patterns and Pd/lr >1. Dykes of cllnopyroxenite formed from LREE-depleted, high Pd/lr, S-saturated, low-Ti tholeiitic magma. The LALPP formed at P ≤ 7-8 kbar in upwelling asthenosphere (T=1300 ± lOCC) below a zone of crustal accretion in a supra-subduction zone environment. -- The HALPPG contain spinel of approximately Cr# = 30, Mg# = 65, and comprise dunite, wehrlite, olivine cllnopyroxenite, gabbro and amphibole peridotite. The HALPPG formed in the lithosphere (T = 900 ± 100°C) at P = 5-9 kbar by combined assimilation and crystal fractionation, which involved fluid-bearing magma and LALPP. The replacement of LALPP by HALPPG involved dissolution of ortho- and clinopyroxene, precipitation of clinopyroxene, plagioclase, Ca-amphibole and phlogopite, and recrystallization of olivine and spinel. In minerals and whole-rock samples of HALPPG, the Mg# is largely controlled by the LALPP protolith, whereas concentrations of Ti, Al, Ca, Na, K and REE are controlled by the magma or fluid. -- The magma parental to the HALPPG was fluid-bearing, LREE-depleted, Sr-rich and SiO₂ -undersaturated, and formed by partial melting of amphibolitized oceanic crust during intra-oceanic thrusting and obduction of the Bay of Islands Ophiolite Complex. The fluid component of this magma became LREE- and Eu- enriched and SiO₂ -saturated by fractionation of Ca-amphibole and reaction with LALPP. As such, this suggests a link between fluids within metamorphic soles of ophiolites, metasomatized mantle peridotites and pyroxenites, and forearc magmatic and fluid processes leading to the formation of wehrlitic bodies and high-MgO, SiO₂ -saturated magmas or fluids of boninitic affinity.


identifier: Ware, Michael James <https://research.library.mun.ca/view/creator_az/Ware=3AMichael_James=3A=3A.html>   (1983) Depositional history and stratigraphy of the Aphibian Tamarack River Formation and the Paleohelikian Sims Formation, western Labrador.  Masters thesis, Memorial University of Newfoundland.

abstract: Alphebian sedimentary rocks of the Tamarack River Formation rest unconformably on the Knob Lake Group in the south-central portion of the Labrador Trough. The formation appears to consist of two transgressive-regressive cycles. The first cycle, present in Member A, consists of subtidal siltstone, which grades upward into a mixed siliciclastic-carbonate unit of shallow subtidal and intertidal origin. The second cycle, recorded by members B and C, is composed of subtidal siltstone which passes upward into the intertidal and fluvial sandstone. Detritus of member A was derived from the north, whereas the provenance of member C was the Superior Province to the west. The formation may be part of the third Aphebian miogeoclinal sequence which developed in the Labrador Trough. The first and second sequences are recorded by the Knob Lake Group. The northern Labrador Trough may contain third sequence strata correlative to the Tamarack River Formation. -- The Paleohelikian Sims Formation rests unconformably on deformed Aphebian strata and consists of a lower unit of terrestrial redbeds and an upper unit of fluvial to shallow-marine quartzarenite. The relatively thin terrestrial redbed unit is composed of three facies, a talus-slope breccia, a pebbly braided-river conglomerate and a sandy braided-river deposit. These facies grade upward into a thick, tabular quartzarenite unit composed of fluvial sandstone, beach conglomerate, and nearshore to shallow-marine sandstone. Throughout its deposition the formation progressively onlapped from west to east and derived its detritus from an uplifted area to the east. The formation may represent post-Hudsonian molasse, and is possibly correlative with the lithologically similar but undated Sakami Formation of northern Quebec. -- Both the Tamarack River and Sims Formations were intruded by tholeiitic dikes and sills of the Elsonian (1.4Ga) Shabogamo Intrusive Suite. Paleomagnetic samples from the suite yield a virtual paleopole position at 3.97°E, 3.4°S with dp = 5.8° and dm = 11.0°, which is similar to the antipole of the nearby Elsonian Michikamau Intrusion.


identifier: Taylor, William R. <https://research.library.mun.ca/view/creator_az/Taylor=3AWilliam_R=2E=3A=3A.html>   (1970) Geology and geochemistry of a uranium-rich area in southwestern Newfoundland.  Masters thesis, Memorial University of Newfoundland.

abstract: A regional geochemical stream sediment survey in southwestern Newfoundland showed several anomalously high uranium areas. Follow-up soil and rock sampling and geological mapping programs were carried out in one of these anomalous areas - the Brinex Lake map-area. -- The area is underlain by granodiorite, which is possibly of metasomatic origin, schist and gneisses. Pegmatite dykes are numerous and some aplite and basic dykes were also found. Rocks of the Brinex Lake map-area are possibly of Pre-Cambrian age. -- No uranium mineralization was found in the rocks although some rocks contained anomalously high uranium values, ranging up to 85 ppm. Uranium in the rocks appears to be associated with biotite-rich lenses in schists and gneisses and in the contact zone between them and the granodiorite. Radioactive inclusions in biotite are believed to be the main source of uranium in these rocks. Red hematite alteration, which is characteristic of known uranium occurrences in other parts of the world, is commonly associated with the biotite lenses. Soil and stream sediment anomalies are closely associated with areas containing abundant biotite lenses. -- Comparisons with known uranium provinces suggests that favourable geological environments for the accumulation of uranium into deposits of economic value exist in southwestern Newfoundland. Radioactive occurrences have been reported in similar rocks along the north shore of the St. Lawrence River and in Nova Scotia and New Brunswick.


identifier: Shearer, James Moxley <https://research.library.mun.ca/view/creator_az/Shearer=3AJames_Moxley=3A=3A.html>   (1970) Detailed grain size analysis of recent Marine sediments and post-glacial history of Port au Port Bay, west Newfoundland.  Masters thesis, Memorial University of Newfoundland.

abstract: Grain size analysis of about 130 bottom grab samples taken from the recent marine sediments of Port au Port Bay have led to the distinction of three sediment types with different, although characteristic, cumulative grain size distribution curves. The three types encountered are: 1) unimodal sands found in areas of high wave and tidal current energies, 2) bimodal silts and clays deposited in the low energy basin areas, and 3) bimodal gravels in areas of medium to high energies. The coarse component of Type No. 3 is often a residual deposit from a time of even higher energy associated with the lower post-glacial sea level. -- Based on this analysis, it is proposed that the characteristic "break" to the finer grades in many fine sand and silty sediments is due to the inherent scarcity in the natural environment of material with diameters between 10 and 40 microns. This size range represents the gap between a fine sand and a clay population, each of which is representative of a different mode of formation. This is in opposition to many workers who believe that this "break" is due to a different mode of transport. -- A correlation between particle diameter and mode of transport is nevertheless attempted. It is based on the assumption that tidal currents do not affect the areas of the bay below the deepest sill which, in turn, is deduced from studies of the faunal distribution and the physical oceanographic properties. Deposition in the basin areas, then, is thought to be from suspension only with the maximum particle diameter in these sediments, after removal of the ice-rafted fraction, being around 0.125 mm. -- The sea level at the time of the last ice retreat from Port au Port Bay (around 13500 yrs. B.P.) was at the "marine limit", more than 100 feet above the present datum. Isostatic recovery of the land area, as a result of glacial unloading, was apparently occurring faster than the accompanying eustatic rise of the sea, a consequence of the returning glacial meltwaters. Following the ice withdrawal sea level fell rapidly until the isostatic component had diminished to a rate equal to that of the eustatic rise, when the lowest post-glacial sea level was registered. This lowest level calculated from the grain size variations within one of the basin cores was around -35 and -45 feet from the present datum. This is in close agreement with the lowest level calculated from the difference between the theoretical rebound curve and the world-wide eustatic curve. Subsequently, with a further decrease in the isostatic rebound rate, the eustatic component was greater and slow submergence of the land area took place.


identifier: Saunders, Cynthia Margaret <https://research.library.mun.ca/view/creator_az/Saunders=3ACynthia_Margaret=3A=3A.html>   (1985) Controls of the mineralization in the Betts Cove ophiolite.  Masters thesis, Memorial University of Newfoundland.

abstract: The focus of this study is the Betts Cove massive sulphide deposit which is located within the Betts Cove Complex, an Ordovician ophiolite sequence that consists of, in ascending stratigraphic order, an ultramafic, a gabbroic, a sheeted dyke and a pillow lava member. The ophiolite is conformably overlain by the Ordovician Snooks Arm Group, a series of sedimentary rocks and basic to andesitic pyroclastic rocks which are intruded by diabasic sills. The ophiolite and the Snooks Arm Group are intruded by or are in fault or unconformable contact with the surrounding rock units. The pillow lava member of the ophiolite is characterized by variolitic textures which are the result of supercooling. The basaltic members of the ophiolite are characterized by unusually low TiO₂ and high Cr, Ni and MgO concentrations; they show similarities to boninites from the Western Pacific and may have formed in a supra-subduction environment. The Betts Cove sulphide deposit is located at the contact between the sheeted dyke and the pillow lava members. It consists of a massive pyrite-chalcopyrite-sphalerite body underlain by a stockwork of pyrite-chalcopyrite. The deposit has a distinctive footwall alteration zone which consists of a core of quartz-chlorite and a halo of chlorite-albite-quartz. These zones are superimposed on a background greenschist assemblage of actinolite-epidote-chlorite-albite-quartz with relict clinopyroxene commonly preserved. The footwall alteration zones can be related to the amount of water which has passed through the rock. The core zone was the area of highest fluid flux (high water/rock ratio); CaO, Na₂O, Sr, and to some extent, light rare earth elements were leached from this zone. The background assemblage was produced by a low water/rock ratio and that of the halo zone by an intermediate water/rock ratio. Fluid inclusion studies show that the fluids had a composition similar to that of seawater. The Betts Cove deposit shows many similarities to the classic Troodos massive sulphide deposits and is thought to have formed in the same way - by re-deposition of metals which were leached from the ocean crust by circulating seawater. Comparable deposits are currently being formed at the East Pacific Rise and the Galapagos Ridge. The site of upwelling of metal-bearing hydrothermal fluids, probably along faults and fracture zones, is the area of greatest fluid flux; thus the core alteration zone underlying the Betts Cove deposit is interpreted to represent the conduit for the mineralizing fluids which deposited the massive sulphide mineralization. The fluids may have been focussed along faults and permeable zones.


identifier: Keats, Harvey Franklin <https://research.library.mun.ca/view/creator_az/Keats=3AHarvey_Franklin=3A=3A.html>   (1970) Geology and mineralogy of the pyrophyllite deposits south of Manuels, Avalon Peninsula.  Masters thesis, Memorial University of Newfoundland.

abstract: The Late Precambrian (Hadrynian) Harbour Main Group of the eastern side of the Central Block of the Avalon Platform of Newfoundland consists predominantly of acidic volcanic rocks which are intruded on the west by quartz monzonite of the Holyrood Plutonic Series. Pyrophyllite deposits, containing mainly pyrophyllite, sericite and quartz, occur in the acidic volcanic rocks close to the Holyrood granite - Harbour Main contact. The deposits are localized by fault and shear zones. They were studied in the field in relation to the host rocks and in the laboratory by means of an X-ray diffraction technique involving the correlation of peak-height ratios with percentage ratios of mineral pairs. The percentages of pyrophyllite, sericite and quartz can be calculated from these ratios. This method can be adapted to a routine industrial analysis. -- The alteration process responsible for the formation of the pyrophyllite deposits was one of metasomatic replacement by late stage hydrothermal solutions related to the Holyrood granite intrusion. The replacement, contemporaneous with deformation, involved the introduction of Si, K, and possibly Al, the movement of K, Na and Si within the alteration zones, and the migration of K, Na, Si and Mg away from the zones. The alteration took place at a total pressure of 1000 bars, a fluid pressure probably somewhat below this, and at a temperature below 380°C, possibly approaching 270°C.


identifier: Robinson, J. W. (James William) <https://research.library.mun.ca/view/creator_az/Robinson=3AJ=2E_W=2E_=28James_William=29=3A=3A.html>   (1987) A laboratory and numerical investigation of solute transport in discontinuous fracture systems.  Masters thesis, Memorial University of Newfoundland.

abstract: The mixing of fluids at fracture intersections was examined, in the laboratory, using fourteen plexiglass models that simulated open fractures with no contact between the fracture walls. Twelve models contained two fully intersecting fractures. One model contained two intersecting but offset fractures (parallel flow model) and one fracture system model contained a total of eleven fractures in two sets of intersecting fractures, all with the same aperture. One set was composed of five parallel fractures and the other set was composed of six parallel fractures. The twelve fully intersecting fracture models were designed to investigate the effects, on mixing, of seven angles of intersection and three fracture apertures. Iodide solution of known concentration was injected into one fracture and distilled water into another (inlet ports). At each of the outlet ports the concentration of iodide and the discharge volume were measured. The ratio of the volumes of distilled water and iodide solution in each of the discharge fractures was compared to calculate the percent mixing at the fracture intersection. -- Testing, conducted at three hydraulic gradients, indicated that essentially no mixing occurred in the fully intersecting fracture models and only nominal mixing occurred in the parallel flow model. In general mixing was found to be dependent only upon the relative size of the inlet and outlet fractures. Testing, using the fracture system model, indicated a similar lack of mixing at six intersections through which the fluid moved. -- A two dimensional finite element model was written to simulate the transport of a conservative solute in a discontinuous, random, fracture system. Mixing at fracture intersections in the numerical model was based on the results of the physical model study. Hence no mixing was allowed to take place at the fracture intersections except that which was due to the differences in the apertures of the inlet and discharge fractures. Using this mixing algorithm the numerical model indicates that more longitudinal and less lateral dispersion takes place than when complete mixing at fracture intersections is assumed. In addition, more longitudinal transport takes place in discontinuous than in continuous fracture systems. These findings indicate that contaminants migrating through fractured media, where the fracture walls are not in contact, will not be dispersed and diluted to the extent that past numerical models have predicted and hence the contaminant will be discharged to the biosphere in much greater concentration than expected.


identifier: Norman, Ryburn E. <https://research.library.mun.ca/view/creator_az/Norman=3ARyburn_E=2E=3A=3A.html>   (1973) Geology and petrochemistry of ophiolitic rocks of the Baie Verte Group exposed at Ming's Bight, Newfoundland.  Masters thesis, Memorial University of Newfoundland.

abstract: The Baie Verte Group, as exposed on the peninsula between Baie Verte and Ming's Bight, consists of a disrupted ophiolite sequence. The rock types range from interlayered ultramafics and gabbro to sheeted diabase dikes overlain by pillow lavas and volcanic sediments. The sequence has been disrupted into five structural blocks separated by fault zones containing serpentinized peridotite and/or talc-carbonate; units within each block are separated by less significant faults. This widespread imbrication is similar to 'schuppen zones' in north-east Shetland as described by Flinn (1958). These structures and other deformation features in the Baie Verte Group are interpreted to be related to early Ordovician emplacement with some effects of later Acadian deformation. -- The Baie Verte Group is chemically similar to other ophiolite sequences such as in Oman and Papua. A parental magma, interpreted to have been a low-Ti and low-K basaltic magma, crystallized under conditions of low oxygen fugacity in the upper crustal zones beneath a mid-ocean ridge, producing the ultramafics-gabbro-diabase-pillow lava sequence observed. -- Mineral occurrences in the area have similar mineralogy (pyrite-chalcopyrite-pyrrhotite-sphalerite) to those of other ophiolite areas such as Betts Cove and Troodos.


identifier: Sandeman, Hamish A. I. <https://research.library.mun.ca/view/creator_az/Sandeman=3AHamish_A=2E_I=2E=3A=3A.html>   (1988) A field, petrographical and geochemical investigation of the Kennack Gneiss, Lizard Peninsula, southwest England.  Masters thesis, Memorial University of Newfoundland.

abstract: The Lizard complex of southwest England is considered to represent a thrust slice of Devonian oceanic crust, emplaced onto the Gramscatho flysch basin during the Middle Devonian. The ophiolite is an incomplete sequence consisting of strongly deformed basaltic lavas and interflow sediments (Landewednack and Old Lizard Head Series schists respectively), overlain by serpentinized peridotites and lherzolites, variable gabbro and a restricted sheeted dyke complex. Intruded into the basal, serpentinized ultramafic rocks are a suite of compositionally banded rocks called the Kennack Gneiss. Excluding some late mafic dykes, the Kennack Gneiss is the youngest rock suite present, because portions of the gneiss intrude and cross-cut the foliations of all the other rock types. -- The banded Kennack Gneiss consists of distinct felsic and mafic fractions. Field relationships with other units indicate an intrusive igneous nature for the Kennack Gneiss and the relationships between the felsic and mafic fractions of the gneiss suggest that magma-mingling and possibly mixing have played a significant role in generation of these rocks. Digestion of plastic gabbroic xenoliths by felsic material, net-veining of silicic material in microgabbro and flame-like interfingering of felsic and mafic fractions all support the proposal of magmatic mingling. -- Field relationships also indicate that the mafic fraction of the Kennack Gneiss is distinct from the hornblende schists, and that some mafic dykes are genetically related to the mafic fraction of the Kennack Gneiss. Variably deformed pegmatitic gabbro within the map area appears to be only slightly older than the Kennack Gneiss and is significantly different in chemistry from the Crousa gabbro. -- Harker variation diagrams for the Kennack Gneiss as a whole show variable trends. The presence of curvilinear trends indicates that a restite separation or in situ metamorphic segregation processes may be discounted as viable hypotheses. Instead, fractional crystallization, thermogravitational diffusion or magma-mixing are favored. The trace element chemistry of the Kennack gneiss indicates that magma-mixing is the most favorable of the three. This is demonstrated through irregular inter end member trends not easily explained through traditional fractional crystallization processes. -- Negative colinear variations with silica dominate the felsic fractions of the Kennack Gneiss. MgO variation diagrams for the mafic fractions of the gneiss show a high degree of scatter, but particular elements (CaO, Na₂O, SiO₂ and Sr) exhibit curvilinear covariance with MgO. These points suggest that the felsic fractions are interrelated through mixing, while the mafic fractions are interrelated through progressive fractional crystallization. This indicates that the chemical and physical evolution of the felsic fractions has been dominated by magmatic mingling and mixing of a silicic magma with a late stage differentiate of the mafic fractions. Although the majority of the chemical data for the felsic rocks supports mixing, a number of elements, Y, Nb, possibly Th and U and the rare earth elements exhibit strong enrichment/depletion trends which are difficult to interpret. However, careful interpretatiqn indicates that the felsic fractions of the gneiss were initially generated through partial melting of a crustal source, intermediate in composition which contained abundant plagioclase and a HFSE bearing phase such as zircon. These crustal melts underwent crystal fractionation of alkali feldspar as well as a LREE bearing phase (monazite?), as indicated by the extreme enrichment of the Y, Nb and possibly the HREE in the most evolved silicic rocks. Following this crystal fractionation, the felsic magma was intruded into a magma chamber containing the mafic fraction of the gneiss. Mixing of the felsic magma and the most differentiated portions of the mafic magma occurred, however, mixing was only local as demonstrated by the mingled state now observed in the field. The mingled and partially mixed magmas were then intruded along the base of and into the Lizard peridotite. Intrusion of the Kennack Gneiss was synchronous with displacement of the Lizard complex from the oceanic regime. The strongly banded character of the Kennack Gneiss resulted from a high strain gradient at the base of the Lizard complex at that time. -- Major element chemistry of the mafic fractions suggest a volcanic arc influence in generation of these rocks. Similarly, trace and rare earth element chemistry in combination with tectonic discrimination diagrams support a volcanic arc setting of generation for the two magmas. These observations have significant implications for the geotectonic history of the Lizard complex.


identifier: Teng, Hau Chong <https://research.library.mun.ca/view/creator_az/Teng=3AHau_Chong=3A=3A.html>   (1974) A lithogeochemical study of the St. Lawrence granite, Newfoundland.  Masters thesis, Memorial University of Newfoundland.

abstract: The St. Lawrence map area is underlain mainly by a sequence of Proterozoic flows, pyroclastics and volcanogenic sediments which are unconformably overlain by a Cambrian sequence of sandstone, siltstone, greywacke, shale and locally nodular limestone and conglomerate. These formations were subsequently intruded (in chronological order) by gabbro, the St. Lawrence fluorite-bearing alaskite granite, and later acidic and basic dykes. The alaskite granite has been dated isotopically by rubidium-strontium at 330 ± 10 million years. -- The St. Lawrence granite is a pink to red granitic rock characterised by a scarcity of ferromagnesian minerals. Petrographic studies show it to be composed essentially of quartz, orthoclase and albite with minor amounts of riebeckite, aegirine, biotite, fluorite, magnetite and hematite. Perthitic and granophyric textures are common. -- Two hundred and fifty rock samples were collected in the map area and 140 granitic rocks were analysed for major elements and 220 for trace elements, showing that it is distinctly high in SiO₂ (average 76.7 per cent), Zr (average 516 ppm), Rb (average 295 ppm) and F (average 1308 ppm), and low in A1₂O₃ (average 10.9 per cent), Ca0 (average 0.36 per cent), Sr (less than 10 ppm) and Ba (average 70 ppm). Mineralogically, it contains relatively sodic plagioclase (average An₁₀) and silica- undersaturated mafic minerals such as riebeckite and aegirine and this is reflected in normative acmite. These chemical and mineralogical features classify the St. Lawrence granite as peralkaline. -- Normative Q-Ab-Or plot of the analyses fall in a field centred on the ternary minimum at 0.5 kb, suggesting a temperature of crystallisation of the granite at about 780°C. It has been considered to be a relatively dry hot melt because of its low PH₂0 minimum composition (i.e. a hypersolvus granite) by the presence of tuffisites and the lack of pegmatites, all also suggesting a shallow depth of intrusion. The magma was probably formed by limited fractional melting at the base of the continental crust or by fractionation of a rather uniform and relatively calcalkaline acid parent. -- The St. Lawrence granite is mineralogically and chemically very similar to the riebeckite-aegirine-bearing granites of Kudaru and Liruei of Nigeria. Although the Traytown granite of Newfoundland is riebeckite-bearing, there is a distinct difference in its trace elements compared to the St. Lawrence granite.


identifier: Wynne, Paula Jane <https://research.library.mun.ca/view/creator_az/Wynne=3APaula_Jane=3A=3A.html>   (1983) A lithogeochemical study of the host rocks of the Strickland Showing.  Masters thesis, Memorial University of Newfoundland.

abstract: The Strickland showing consists of several zones of Zn-Pb-Cu-Ag mineralization hosted in a sequence of volcanic, volcaniclastic and sedimentary rocks which form a coherent belt stretching for 100 km along the south coast of Newfoundland. The sequence has been metamorphosed to upper greenschist facies and subjected to inhomogeneous cataclastic deformation. The mineralization identified in five principle zones (Main, Bog, Silver Hill, Copper and Carrot Brook) is interpreted to have been emplaced synvolcanically. This investigation is concerned with the identification of lithogeochemical signatures in the host rocks, produced by the mineralizing events. -- A total of 294 surface and 292 diamond drill core samples were collected in the Strickland area. They were analyzed for SiO₂, TiO₂, Al₂O₃, FeO, MnO, MgO, CaO, K₂O, Na₂O, P₂O₅ and LOI (loss on ignition). Most were also analysed for Cu, Pb, Zn and Ag and a selected number of surface samples for Zn, Sr, Rb, U, Th, Ga and Y. -- Two statistical approaches were taken in which regression techniques were used to generate residual values for elements in an effort to remove the effects of the rocks' primary composition, i.e. to define anomalies related to mineralization irrespective of lithology. In the first approach discriminant analysis showed that the elements TiO₂, Al₂O₃ and FeO contributed most to the discrimination between lithologies. These elements were then used as independent variables in curvilinear regression equations with which residual values were calculated. A second more refined approach was taken where the data were divided into three groups based on lithology, (igneous, sedimentary and mixed) and TiO₂ (an index of differentiation) was used as the independent variable in curvilinear regression equations to generate residuals for the igneous and mixed groups. Anomalous residual values combined with anomalous analyses from the sedimentary group are referred to as the second pass anomalies. These were found to be more effective in identifying anomalous samples irrespective of lithology than plots of the raw data or first approach residuals. -- The surface distribution of the anomalies from the second approach tend to be in sporadic, elongate, strike-parallel clusters except for a single cluster which stretches southeast across strike from the Copper Zone. It is marked by a lithogeochemical signature typical of hydrothermal conduits as observed beneath other massive sulphide deposits (positive SiO₂ and negative Na₂O, Al₂O₃ and CaO anomalies). Mineralization, typically silver rich, associated with carbonate-tremolite gangue (Main Zone and especially in the Silver Hill Zone) is marked by persistant positive MgO, CaO, FeO and negative Na₂O and SiO₂ anomalies. -- A horizon 25 m stratigraphically below the Silver Hill Zone characterized by negative Na₂O anomalies and positive K₂O anomalies is interpreted to be a stratiform hydrothermal conduit. -- The Strickland showing is analogous in some respects (age, host lithology, mineralization, Pb-isotopes) to the Bathurst camp of New Brunswick and it is therefore reasonable to speculate that, as in the Bathurst camp, other sulphide accumulations lay, as yet undiscovered, in the sequence of rocks which hosts the Strickland. -- When compared with regionally correlative rocks, those associated with the Strickland rocks (felsic flows in particular) are clearly anomalously low in sodium. The low sodium concentration of the Strickland volcanics, typical of the host rocks of many other volcanogenic massive sulphide deposits may prove to be a useful exploration tool in identifying such mineralized areas on a regional basis.


identifier: Nowlan, Godfrey S. <https://research.library.mun.ca/view/creator_az/Nowlan=3AGodfrey_S=2E=3A=3A.html>   (1973) Conodonts from the Cow Head Group, western Newfoundland.  Masters thesis, Memorial University of Newfoundland.

abstract: At its type section near the village of Cow Head on the Great Northern Peninsula, Newfoundland, the Cow Head Group consists of carbonate breccias, micrites, graded bioclastic limestones and non-calcareous shales with minor sandstones, shaly limestones and non-calcareous siltstones. Many of the limestones are laminated and bioturbated, and some are partially to completely dolomitised. The section is only 300m. thick and ranges in age from Middle Cambrian to Middle Ordovician. It was transported westward by gravity sliding during the Middle Ordovician and it now overlies shelf facies limestones. The sequence was carefully logged and sampled for conodonts in order to determine the existence and extent of conodont zones, and to define the transition between the Cambrian and Ordovician Systems in terms of conodont biostratigraphy. -- Yields of conodonts from the samples are generally sparse and the faunas are rarely diverse. The conodonts are classified using multielement taxonomy wherever possible, and those elements which do not fit into any known multielement species are listed under form taxonomy. -- The Cow Head Group is divided into 14 Units primarily on the basis of conodonts. No conodonts were recovered from the Middle Cambrian and thus it is correlated on the basis of previously reported trilobite faunas. Reasonable correlation can be made with the conodont zones of Balto-Scandia erected by Lindström and Bergström for the Lower Ordovician, however not all of these zones have been recognised. The zones erected by Lindström for the Volkhovian and Kundan Stages of the Baltic Shield (Baltoniodus triangularis Zone to the Amorphognathus variabilis Zone) are not recognised in the Cow Head sequence. Tentative correlations are likewise made with the Australian Lower Ordovician conodont zones. Only a very poor correlation of the Cow Head Group with the conodont zones of the mid-western United States exists, emphasising the difficulty of correlating cratonic and extra-cratonic conodont faunas. -- The Cow Head Group was deposited near the base of the Lower Paleozoic continental slope of eastern North America. It was laid down as a series of mass gravity slides which flowed from the outer shelf and upper slope into an area of active deposition and redistribution of thin carbonate and non-calcareous muds.


identifier: Minatidis, Demitris George <https://research.library.mun.ca/view/creator_az/Minatidis=3ADemitris_George=3A=3A.html>   (1976) A comparative study of trace elements geochemistry and mineralogy of some uranium deposits of Labrador, and evaluation of some uranium exploration techniques in a glacial terrain.  Masters thesis, Memorial University of Newfoundland.

abstract: The Aillik Group of Aphebian metavolcanic and metasedimentary rocks is situated in the Makkovik subprovince of Labrador, north of the Grenville Front. -- The Kaipokok volcanic and the Walker Lake-White Bear Mountain belts consist of flow-banded and porphyritic rhyolite lavas, quartzites, minor interbedded basalt lavas and volcanic tuff. -- Metamorphism has remained in the greenschist and amphibolite facies throughout tectonism. -- One hundred and seventy rock samples were collected from eight uranium showings in the map area and were analysed for 10 trace elements, namely Zr, Sr, Rb, Zn, Cu, Ba, Ni, Cr, U and Th. One hundred and ten thin sections were examined and autoradiographed. Uranium in these showings is present possibly in the following forms: -- 1) In uranium minerals of davidite composition. -- 2) In lenses of dark bituminous material. -- 3) As ions dispersed in such minerals as hornblende, quartz, feldspar and in part in some other minerals. -- 4) As ions adsorbed on to hematite. -- 5) As an isomorphous admixture in the minerals biotite, epidote, zircon and sphene. -- 6) As independant compounds within magnetite. -- 7) As submicroscopic inclusions of uranium minerals of unknown compositions within garnets, sodic amphiboles and feldspar porphyroblasts. -- Results obtained from different uranium exploration techniques in a glaciated terrain, e.g. radon detection, nearshore lake sediment geochemistry, lake water and air-borne surveys, should be interpreted in conjunction with glacial geology and other physiographic factors affecting their applicability.


identifier: Murthy, Cummuluru S. <https://research.library.mun.ca/view/creator_az/Murthy=3ACummuluru_S=2E=3A=3A.html>   (1966) Design and calibration of an astatic magnetometer and the study of remanent magnetization of some Newfoundland rocks.  Masters thesis, Memorial University of Newfoundland.

abstract: An astatic magnetometer utilizing transversely magnetized magnets of large specific dipole moment has been designed and calibrated. With a period T = 4.6 seconds, P/I = 1.35 x 10³ c.g.s. units, and an astaticism of 6 x 10³ or more, the performance of the instrument compares well with that of more sensitive astatic magnetometers described in the literature. The present reciprocal sensitivity of 3.9 x 10⁻⁷ oe/mm scale deflection is sufficient for the accurate measurement of remanent magnetization of specimens with minimum intensity J = 1 x 10⁻⁵ e.m.u./cm. A tenfold increase in sensitivity, permitting measurement with relatively short period (T < 15 sec.) of the more weakly magnetic sedimentary rocks, is easily accomplished by changing the suspension, but has not been carried out pending removal of the instrument to a magnetically less disturbed site. At the present location on the second floor of a university science building, serious short-period mechanical vibrations also presented a problem at first, but these have been virtually eliminated by means of a specially designed, top-heavy spring suspension for the magnetometer. -- The magnetometer has been used to measure the natural remanent magnetization of rocks collected in 1965 in three areas of Newfoundland. A detailed study of 25 samples of flat-lying basalt from two sites on the Labrador Coast yielded a mean direction of NRM with azimuth, A = 21.2ﾟ; dip, D = 76.5ﾟ; and radius of circle of confidence, [special character omitted] ₉₅ =  7.6ﾟ. This direction is too close to that of the present geomagnetic field or axial dipole field at these sites to exclude the possible presence of a significant unstable component of magnetization. Initial stability tests using only alternating field demagnetization are still inconclusive, and formulation of palaeomagnetic conclusions from the Labrador results, which could have a bearing on such problems as the age of the basalts or the postulated rotation of Newfoundland, must await further tests, including thermal demagnetization. -- Some preliminary palaeomagnetic measurements were carried out on sedimentary rock samples collected off Notre Dame Bay on the island of Newfoundland, and on the Grand Banks of Newfoundland. The former collection consisted of grey and red argillites of Ordovician age from four sites, while the latter were three samples of microbreccia; these had been oriented under water and recovered by divers from the Virgin Rocks shoals, which are 170 miles east of Gape Race, on the Avalon Peninsula and probably of late Precambrian age. The results, which are still tentative, are discussed in the light of earlier palaeomagnetic work in Newfoundland.


identifier: Coniglio, Mario <https://research.library.mun.ca/view/creator_az/Coniglio=3AMario=3A=3A.html>   (1985) Origin and diagenesis of fine-grained slope sediments : Cow Head Group (Cambro-Ordovician), western Newfoundland.  Doctoral (PhD) thesis, Memorial University of Newfoundland.

abstract: The Cow Head Group is a base-of-slope apron deposit composed of 5 lithofacies: (1) conglomerate, (2) calcarenite, (3) siltstone, (4) shale, and (5) lime mudstone. Conglomerates were deposited by debris flows and the calcarenite grainstones by high-density turbidity currents. Siltstones and shales represent interbedded fine-grained turbidites and terrigenous hemipelagites. Rhythmically-bedded parted, ribbon, and nodular lime mudstones, composed mostly of microspar and pseudospar, resulted from the interplay of climatically-controlled carbonate-abundance cycles and event deposits. Peloids and intraclasts, derived mainly from the breakdown of the calcified algae Girvanella and Epiphyton, are the most important allochems in the fine-grained sediments. -- Burial compaction occurred mainly in argillaceous sediments. Limestones are uncompacted and demonstrate only minor pressure solution effects. Intrastratal deformation was due to submarine failure and layer-parallel compression during Taconic orogenesis. Subtly-expressed synsedimentary deformation fabrics indicate that slope failure was more common than is apparent based solely on the presence of intraformational truncation surfaces and slide masses. -- In conglomerates, clasts with diagenetic microfabrics identical to those of the thinly-bedded, fine-grained sediments indicate that lithification (calcite authigenesis, early dolomitization, and some silicification) occurred within several metres of the sediment-water interface. Carbon isotope analyses suggest that carbonate precipitation was driven by bacterial sulphate reduction and methane generation. Trace element (Mg, Fe, Mn, and Sr) and cathode luminescence patterns record calcite precipitation from progressively more reduced pore-waters. These patterns are indistinguishable from those generated during meteoric-water diagenesis. -- Cathode luminescence microfabrics of radiaxial fibrous calcite from shallow-water boulders in conglomerates and in situ displacive fibrous calcite indicate that these crystals are composite and grew both as spherocrystals and unit crystals. Aggrading neospar on the margins of mudstone beds and nodules resulted from decreased nucleation density and precipitation of progressively younger calcite, commonly as asymmetrical, irregular increments. -- Three types of dolomite are differentiated: (1) detrital, (2) early diagenetic, and (3) late diagenetic. Silt-size particles of detrital dolomite were derived from weathering of older carbonates or penecontemporaneous dolomite from the adjacent, shallow-water platform. Diagenetic dolomite occurs both as a replacement and a pore-filling phase. Early dolomitization was synchronous with or postdated the main phase of calcite authigenesis. Late dolomitization is related to tectonic faults and joints. Silicification also has a protracted diagenetic history, but its distribution is controlled primarily by the abundance of radiolaria and siliceous sponge spicules.


identifier: Aydin, Nurdan Sebile <https://research.library.mun.ca/view/creator_az/Aydin=3ANurdan_Sebile=3A=3A.html>   (1995) Petrology of the composite mafic-felsic plutonic rocks of the Fogo Island Batholith: a window to mafic magma chamber processes and the role of mantle in the petrogenesis of the granitoid rocks.  Doctoral (PhD) thesis, Memorial University of Newfoundland.

abstract: Field, petrographic, geochemical, geochronologic (U/Pb) and Nd isotopic studies of the diverse plutonic rocks in the Tilting area, Fogo Island, NE Newfoundland, were carried out to elucidate the relative roles of crust and mantle in the petrogenesis of this example of Siluro-Devonian magmatism in the Appalachian-Caledonide orogen. -- The plutonic rocks of the study area are part of the Fogo Island Batholith (FIB) and display a wide range of fabrics, textures, mineralogies and compositions. Based primarily on field and petrographic characteristics they have been divided into three main suites, these are: the Tilting Layered Suite (TLS) composed of layered ultramafic, mafic and intermediate rocks; the Fogo Suite (FS) dominated by monzogranite with minor amounts of granodiorite; and the Wild-Sandy Cove Suite (W-SCS) containing mainly quartz diorite and diorite with minor amounts of leucogabbronorite, hornblendite and granodiorite. -- The TLS is a composite intrusion and contains four main zones (Zones I-IV). Layering features (physical and chemical) of the suite reflect the complex interaction of several magma chamber processes including magma replenishment with or without subsequent mixing of newly introduced and residual magmas, in situ crystallization, current deposition and postcumulus/subsolidus modifications. Effects and consequences of these processes vary from place to place within the suite. Two distinct magma compositions have been recognized in the TLS (quartz-tholeiitic, Zones I-III and olivine-tholeiitic, Zone IV). The interrelationship between silica-saturated and silica-oversaturated magma types is attributed to differences in pressure of partial melting of the same or similar source material(s). Variation in water pressure and silica activity are significant parameters controlling the sequence of crystallization within the suite. -- The TLS shows slight to strong LREE enrichment relative to HREE and significant negative Nb-anomalies. There is significant εNd variation within the suite from -0.1 to +5.1 (at 420 Ma) and much of the range of this heterogeneity appears to have existed before emplacement of magma batches into the chamber which suggests crustal contamination prior to intrusion. -- The FS and W-SCS are geochemically and isotopically distinct, temporally unrelated, high-level granitoid intrusions. The FS has been dated at 420 ±2 Ma and is a C-type, metaluminous granitoid body. It typically displays: i) LREE enrichment relative to HREE with flat HREEN patterns; ii) negative Eu- and Nb- anomalies; and iv) relatively positive εNd values (-1.0 to +1.3). The FS is interpreted to have been mainly derived from lower crustal material. -- The W-SCS has been dated at 408 ±2 Ma and is an H-type, metaluminous, composite intrusion. It contains three distinct units: the Pigeon Island Unit-hornblendite; the Sandy Unit-leucocratic gabbronorite; and the Wild Unit - quartz diorite, tonalite and minor granodiorite. The suite is characterized by i) LREE enrichment relative to HREE with steeply sloping REEN patterns; ii) no notable Eu- anomalies; iii) significant negative Nb- anomalies; and iv) a wide range of Nd isotopic compositions (+0.3 to +3.2). -- The Wild Unit dominates the W-SCS and typically contains various types of mafic-intermediate dykes, microgranular enclaves and country-rock xenoliths. Magma mixing and mingling processes between mantle-derived mafic and lower crust-derived felsic magmas played important roles in the evolution of the Wild Unit. -- The proposed petrogenetic model envisages that the TLS, the FS and the W-SCS are the products of the same mechanism, i.e. mafic magma underplating the lower crust. Each suite represents a significantly different mode of interaction between mafic magmas and the lower crust. The mode of such interactions varies from mass transfer (i.e. crustal contamination- the TLS) → heat transfer ± minor mass transfer (crustal anatexis with or without a minor contribution from mantle-derived mafic magma- the FS)→ to both mass and heat transfer (magma mixing and mingling- the W-SCS).


identifier: Craig, David F. <https://research.library.mun.ca/view/creator_az/Craig=3ADavid_F=2E=3A=3A.html>   (1996) Non-natural deaths in Newfoundland and Labrador 1951-1986 : manner of death, temporal and geographic rate variation and risk factors.  Masters thesis, Memorial University of Newfoundland.

abstract: The reported rates of suicide, homicide and traffic accident fatalities in Newfoundland and Labrador have consistently been lower than those in Canada as a whole. Whether the differences in these rates reflect different reporting practices or true differences in the rates of these manners of death has been in some dispute, particularly in the case of suicide. This issue is addressed by developing operational definitions for natural and non-natural deaths and for each manner of non-natural death. The registrations of all non-natural deaths occurring in Newfoundland and Labrador during every fifth year from 1951 - 1986 are reviewed and the operational definitions used to select the non-natural deaths and assign a manner of death to each of them. The numbers and rates of each manner of non-natural death thus determined are compared with those recorded by staff of the Registry of Births, Marriages and Deaths and with Statistics Canada figures. Factors determining which non-natural deaths were registered by non-physicians are briefly reviewed as are the risk factors for each manner of non-natural death. -- There is agreement between the manners of death assigned by Vital Statistics personnel and those assigned in this study at at least a "probable" level of confidence in 89.9% of deaths studied and at the "almost undoubted" level of confidence in 62.6% of deaths studied and disagreement in 3.8 % of deaths studied. Suicides appear under-reported by approximately 20% in Statistics Canada figures; 6% are reported as "unknown" or "undetermined" deaths, 9% are reported as due to other manners of death, chiefly non-traffic accidents and 5% are reported as suicides on death records but do not appear as such in Statistics Canada figures.


identifier: Misra, Shiva Balak <https://research.library.mun.ca/view/creator_az/Misra=3AShiva_Balak=3A=3A.html>   (1969) Geology of the Biscay Bay - Cape Race Area, Avalon Peninsula, Newfoundland.  Masters thesis, Memorial University of Newfoundland.

abstract: This thesis is a general geological study of the previously unmapped Biscay Bay - Cape Race area, the extreme southeastern part of the Avalon Peninsula of Newfoundland. The area is underlain by a thick sequence of Precambrian sedimentary rocks belonging to the Conception Group and the St. John's Formation of the Cabot Group. -- Some of the important aspects of this thesis are the discovery of fossils in the Precambrian rocks, three fold classification of the Conception Group, recognition of the St. John's Formation for the first time in the area, and description of the regional structural pattern. -- The thesis is illustrated by figures and plates. Those pertaining to the primary sedimentary structures are of special significance in deciphering depositional environment of the rocks. The coastal geology is described in four plates on a scale of 1:10,000 and a geological map with the location of these plates on a scale of 1:50,000.


identifier: Hiller, James <https://research.library.mun.ca/view/creator_az/Hiller=3AJames=3A=3A.html>   (1967) The foundation and the early years of the Moravian Mission in Labrador, 1752-1805.  Masters thesis, Memorial University of Newfoundland.

abstract: The old protestant Church of the United Brethren, commonly known as the Moravian Church, was revived by Count Zinzendorf in the 1720's. Attention soon turned to foreign missions, and one of the earliest was in Greenland. It was decided to extend the work to the Labrador Eskimos, and after an abortive attempt to establish a mission on the coast in 1752, a more determined programme was undertaken in the 1760's under the leadership of Jens Haven. With the blessing of government, a mission station was established at Nain in 1771, administered jointly by the German and English branches of the Moravian Church. Other stations were established at Okkak (1776) and Hopedale (1782). -- The policy of the mission was to contain the Eskimos in the north, and to gather them into regulated Christian communities established on traditional Moravian lines. The difficulties were many. The mission could not provide a complete economic substitute for the southern trader, and the policy of containment did not fully succeed. Also, the realisation of the settled community ideal involved far-reaching economic, social and religious changes for the Eskimos, which took far longer to occur than the missionaries originally anticipated. The mission had high standards and was not prepared to compromise. There were not many conversions in the early years, but as the mission became part of the established scene, so the Eskimos' reliance on economic and social services increased; the journies south gradually ceased, and mission schools began to have an effect on the young people. The presence of the mission, and of convert groups following an alien pattern of life disrupted the uniformity of Eskimo society - a uniformity which was reestablished by the convulsive "revival" of 1804-5. This established mission dominance from Okkak to Hopedale and brought into being the settled community, although in a modified form to suit the Labrador environment.


identifier: Moreton, Christopher <https://research.library.mun.ca/view/creator_az/Moreton=3AChristopher=3A=3A.html>   (1984) A geological, geochemical and structural analysis of the Lower Ordovician Tulks Hill Cu-Zn-(Pb) volcanogenic massive sulphide deposit, central Newfoundland, Canada.  Masters thesis, Memorial University of Newfoundland.

abstract: The Tulks Hill Cu-Zn-(Pb) prospect is a volcanogenic massive sulphide deposit located in central Newfoundland. Four sulphide lenses, with a total tonnage of less than 1 million tons, are hosted by felsic pyroclastic and volcanic rocks of the pre-Caradoc Victoria Lake Group. A relative abundance of both felsic rocks and Zn and Pb, distinguishes this deposit from the stratigraphically equivalent ones of Notre Dame Bay. -- Hydrothermally altered rhyolitic-dacitic pyroclastic and volcanic rocks outcrop in the footwall, whereas a tuffaceous chert and iron formation occur in the hangingwall. Chequerboard albite, Fe/Mg- chlorite, sericite and quartz overgrowths on primary quartz phenocrysts, are characteristic alteration features in the footwall. The immediate stratigraphic base of the deposit has K- and Mg(Fe)-rich zones; these zones are thought to have formed at the locus of hydrothermal fluid exhalation. A subvolcanic intrusion, called the Raven rhyolite, is comagmatic with the footwall rocks. It contains secondary microcline (K-enrichment) and sulphide-rich veinlets, suggesting that it played a part in the mineralising process. -- Banded sphalerite-chalcopyrite-galena mineralisation generally overlies massive pyritite; the former two minerals are also common in the siliceous stockwork. Galena and tennantite become more common towards the hangingwall, apparently at the expense of chalcopyrite, while arsenopyrite is sporadically distributed. Covellite, bornite, digenite, electrum, magnetite, ilmenite and marcasite are minor components. -- Dolomite - sericite and siderite - Fe-chlorite are characteristic mineral assemblages of the tuffaceous chert and the iron formation, respectively. Pyrite is the dominant sulphide in these chert-rich chemical sediments. -- Tight to isoclinal folding, with faulting parallel to the axial planes, is the best developed phase (D1) of the three documented deformation episodes. Recumbent folding is inferred to pre-date D1 since the stratigraphy is inverted. Mobilisation of the more plastically deformed sulphides accompanied the development of the SI schistosity. D1 is thought to have occurred in a brittle-ductile regime since annealed pyrite, with distinct pressure shadows, both oriented subparallel to S1, typically lie adjacent to zones of granulated pyrite (fault zones?).


identifier: Pickett, Jacob Wayne <https://research.library.mun.ca/view/creator_az/Pickett=3AJacob_Wayne=3A=3A.html>   (1988) A geological and geochemical study of the Skidder basalt and Skidder trondhjemites : and the geology, ore petrology and geochemistry of the Skidder Prospect and its accompanying alteration zone: Buchans area, central Newfoundland.  Masters thesis, Memorial University of Newfoundland.

abstract: The Skidder Basalt, which outcrops in an area of central Newfoundland immediately to the northwest of Red Indian Lake and approximately 12 km southwest of the town of Buchans, is a spilitized, tholeiitic, sub-alkaline assemblage composed mainly of mafic yariolitic and non-variolitic pillow lava, mafic pillow breccia and massive mafic flows; these extrusive rocks are interlayered with lesser amounts of mafic pyroclastic rocks and chert, and are intruded by diabase dykes. Units typically strike northeast to east-northeasterly and dip steeply; facing directions are typically northwesterly, although local reversals, particularly in the vicinity of the Skidder Prospect, are noted. Foliations trend northeasterly and dip steeply. Several northeasterly, northerly and northwesterly trending lineaments are evident on aerial photographs, and many correspond to linear magnetic features. -- Rocks of the Skidder Basalt are dominated by secondary mineral assemblages. Typically, albitized plagioclase phenocrysts occur in an intergranular to intersortal groundmass of albite, chlorite, quartz, dense granular sphene, and variable amounts of subhedral to acicular opaque minerals. Primary clinopyroxene and chromite, and secondary calcite, amphibole and epidote are constituents of some samples. Clinopyroxene and albitized plagioclase in some low-Zr Skidder basalts exhibit quench-texture morphologies. Formation of varioles, present in some of the low-Zr Skidder basalts, is suggested to be a result of quenching. Spilitization of the Skidder Basalt has involved albitization of plagioclase, chloritization of basaltic glass, alteration of ferromagnesian minerals to chlorite and lesser amphibole, and alteration of opaque Fe-Ti oxides to dense intergranular sphene. Geochemically, spilitization has resulted in redistribution of SiO₂ and total iron, removal of K₂O and MgO, and extensive addition of Na₂O. The spilitization is suggested to have resulted from interaction of the rocks with circulating seawater under conditions of low seawater/rock ratios. -- The chemistry of Skidder Basalt clinopyroxenes and chromites suggests it has greater similarity to ocean-floor basalts than to basalts formed in an island arc environment. The Skidder Basalt rocks define tholeiitic trends and plot either within the ocean floor basalt field or overlap the ocean floor basalt and island arc tholeiite fields on trace element variation diagrams. It is geologically and geochemically more similar to the pillow lava sections of ophiolite complexes than to the Buchans Group basalts. The Skidder Basalt probably formed in an extensional tectonic environment at a slow-spreading oceanic or back-arc basin ridge. -- Low-Al₂O₃, oceanic-type trondhjemite dykes and pods intrude, or are interlayered with, the Skidder Basalt in places. They are chemically similar to trondhjemites considered to represent late magmatic differentiates of basaltic magma. -- The Skidder Prospect is an ophiolite-type volcanogenic massive sulphide deposit hosted by basaltic pillow lavas, mafic pillow breccias and aquagene tuffs of the Skidder Basalt. Brecciated, quartz-veined, unlayered and lesser bedded jasper and jasper-rich siltstone are spatially associated with the massive sulphides. Trondhjemite dykes intrude rocks in the Skidder Prospect area in several places. -- The deposit contains possible and probable reserves of 200 000 tonnes grading 2% copper and 2% zinc accompanied by very minor amounts of lead. The sulphides occur mainly in two lenses composed of semimassive to massive unlayered and layered pyrite containing lesser amounts of chalcopyrite and low-iron sphalerite. Rare galena, hematite and magnetite are also noted. Quartz, chlorite and lesser calcite are the predominant gangue minerals. Abundant disseminated sulphides, mostly pyrite, occur in a quartz and/or chlorite ± talc-rich stringer zone underlying the massive sulphides. -- Distinct alteration zones characterized by secondary mineral assemblages envelop the massive sulphide lenses and flank the underlying stringer zone, typically up to 150 m away from the sulphide-bearing zones. The alteration primarily involves large increases in the amount of intersertal chlorite and quartz; replacement of mafic minerals by chlorite; and replacement of albitized plagioclase by quartz and lesser phengitic sericite. Quartz has been removed and replaced by chlorite, in places. Chlorites from the alteration zone are significantly enriched in magnesium relative to those of typical spilitized Skidder Basalt. Calcite and epidote, which occur in abundance in the Skidder Basalt, are absent in the most intensely altered rocks of the Skidder Prospect alteration zone. -- Geochemically, the alteration is characterized by sporadic enrichment of K, Rb, Ba and Pb; depletion of Ca, Sr and Na; and redistribution of Si in most of the altered rocks. Magnesium and zinc are enriched in intensely chloritized zones. The Zn probably occurs in tiny sphalerite grains intimately associated with high-Mg chlorite. The sporadic enrichment of K and related elements is evident up to 400 m away from the sulphide-bearing zones; the other geochemical effects are recognizable only about 150 m away. Incompatible elements Zr, Y, P and, to a lesser extent, Ti; and compatible elements Cr and Ni have remained stable, even in intensely altered rocks. Chondrite-normalized rare earth element patterns associated with sulphide-poor samples, including some that are relatively unaltered to others that are silicified and intensely chloritized, are similar to those of spilitized Skidder Basalt. Sulphide-rich samples are depleted in REE concentrations relative to the others and some show relative depletion of Ce and the middle REE; characteristics shown by chondrite-normalized REE patterns for seawater. -- Lead isotope ratios of the Skidder prospect sulphides are some of the least radiogenic of Newfoundland mineral deposits. On the ²⁰⁷Pb/²⁰⁴Pb vs. ²⁰⁶Pb/²⁰⁴Pb diagram, they plot along the mantle lead evolution curve of Zartman and Doe (1981). -- The genetic model suggested for formation of the Skidder Prospect is similar to that proposed for other ophiolite-related massive sulphide deposits. Metals are suggested to have been leached from underlying rocks by heated, deep circulating, modified seawater possibly similar in composition to that being emitted at present on the East Pacific Rise. The metals were probably carried in solution as chloride complexes. Local faulting provided upward access to the seafloor for the metal-bearing hydrothermal fluids where the massive sulphides are suggested to have been deposited possibly in a manner similar to those now forming on the East Pacific Rise. Mixing between the hot, upwelling, metal-bearing hydrothermal fluid and cool, shallow-convecting seawater is suggested to have produced the associated alteration effects and the disseminated-sulphide stockwork zone. Much of the spatially associated jasper has probably been produced by oxidative leaching of sulphides exposed on the seafloor.


identifier: Atkinson, Lee Chaflin <https://research.library.mun.ca/view/creator_az/Atkinson=3ALee_Chaflin=3A=3A.html>   (1986) A laboratory and numerical investigation of steady-state, two-regime, radial flow to a well from rough, horizontal, deformable fractures.  Doctoral (PhD) thesis, Memorial University of Newfoundland.

abstract: A numerical and laboratory study was undertaken to obtain a better understanding of the production-drawdown response of a well completed into an aquifer whose primary flow conduits are horizontal fractures. -- In the first phase of the study, a finite-element model was developed to evaluate the effects of fracture aperture and relative roughness on the nature of flow within the fractures and the compounding effect of the fractures closing in response to drawdown-induced increases in effective stress. The flow code of the model simulates steady-state, two-regime (i.e., both laminar and turbulent) radial flow in a series of horizontal, rough fractures of fixed aperture using empirically derived flow laws from the literature. The deformation code models the rock as an elastic medium and follows a user-defined constitutive curve for the stress-deformation behavior of the fractures in order to simulate their closure under the fluid pressure distribution determined by the flow routine. A coupled solution, using fluid pressure as the linking parameter, is obtained by iterating between the two routines. -- For the laboratory phase of the investigation, a concrete cylinder 1.5 m in diameter by 3.0 m high was fabricated with a single, cast-in-place horizontal fracture. More than 60 tests involving constant discharge, variable discharge, and constant injection rate were conducted on the physical model. In addition to flow rate, the laboratory arrangement permitted the varying of boundary fluid pressures, the load applied to the top of the cylinder, and the wellbore size. -- The numerical model closely simulated the results of tests when the fracture was open (i.e., with no contact area) using the true geometric characteristics of the fracture. When the fracture surfaces were in contact, however, the closest simulations were obtained using an "effective aperture" in the range of 0.3-0.8 of the best estimate of the true geometric aperture. -- The results of this investigation demonstrate that non-linear flow in fractures within a few tenths of a meter of the wellbore can comprise a significant portion of the total drawdown in a well. The results also indicate that the coefficient of the well loss term in the classical step-drawdown equation is not a constant (as usually assumed) but increases as the discharge rate increases. One of the more practical findings of this study is that reaming some wellbores in fractured rock aquifers could minimize well losses and lead to improved efficiency in their performance. -- Key words: aquifer evaluation; aquifer testing; dewatering; drawdown; fracture permeability; groundwater flow; groundwater movement; mine drainage; turbulent flow; well hydraulics; well testing; wells.


identifier: Utting, John <https://research.library.mun.ca/view/creator_az/Utting=3AJohn=3A=3A.html>   (1966) Geology of the Codroy Valley, Southwestern Newfoundland, including results of a preliminary palynological investigation.  Masters thesis, Memorial University of Newfoundland.

abstract: A detailed field mapping programme and palaeontological study of Codroy Valley area, southwestern Newfoundland, has yielded evidence that the boundary between the Codroy Group (Mississippian) and the Searston beds-Barachois Group (Upper Mississippian and Pennsylvanian), as mapped by earlier workers, required emendation. -- A general lack of diagnostic macrofossils in critical areas has been commented on by previous workers, and microfossils have been listed only in a few cases, but little work appears to have been done in this field. Rock samples were collected from the map area and later investigated in the laboratory for microfossils. Eighty eight rock samples were macerated for spores and good diagnostic assemblages were found in six of these. Productive samples were found in the Codroy Group, Searston beds and the Barachois Group, comprising a total spore florule of fifteen genera. These included Convolutispora, Lophotriletes, Lycospora, Reticulatisporites and Verrucosisporites from the Codroy Group; Convolutispora, Lycospora, Perotrilites and Raistrickia from the Searston Beds; and Calamospora, Cirratriradites, Densosporites, Florinites, Granulatisporites, Knoxisporites, Leiotriletes, Lophotriletes, Savitrisporites nux and Schopfipollenites from the Barachois Group. -- Five previously unrecorded localities containing ostracods were found and specimens of Glyptopleura sagae? and Paraparchites sp. were identified. A number of new macrofossil localities were also discovered comprising a total assemblage of 15 genera and 17 species. Vertebrate skeletal remains and fossil trackways of tetrapods were found in rocks of the Codroy Group. -- Structural studies revealed four general fault trends in the Codroy Valley area. A detailed sedimentary investigation was made of a coastal portion of the Searston bed sequence. Here, more than 70 diastems were counted separating cyclothems made up of conglomerate-sandstone units and lutite units. The depositional environment in which they were laid down appears to have been one of fluviatile sedimentation under warm humid climatic coiKiitions. -- Five lithostratigraphic types - coal, limestone, arkosic sediments, a boulder (conglomerate) bed, bedded chert - were investigated with a view to establishing marker or key beds in the Searston beds-Barachois Group. The first four types proved inadequate for the role of marker beds. Evidence is given for the continuity of a chert bed permitting it to be used for a key bed. The boundary between the Searston beds and the underlying Codroy Group is arbitrarily chosen at the base of this chert bed.


identifier: Mullins, John <https://research.library.mun.ca/view/creator_az/Mullins=3AJohn=3A=3A.html>   (1961) Geology of the Noel Paul's Brook area, central Newfoundland.  Masters thesis, Memorial University of Newfoundland.

abstract: This thesis is concerned with a study of the general geologic features of the Noel Paul’s Brook area in Central Newfoundland, with emphasis on the systematic description and classification of rock types. -- In the gently rolling terrain the remnants of two Cenozoic erosion surfaces may still be recognized. As a result of Pleistocene glaciation the countryside has been left with a think mantle of boulder clay, but because of two conflicting lines of evidence no definite conclusion as to the direction of glacial ice motion could be reached.  -- The bedrock geology is characterized by narrow - often persistent - bands of clastic sedimentary rocks and volcanic formations striking approximately northeast. Their total thickness, if the possibility of repetition through isoclinal folding is disregarded, is over 30,000 feet. With the exception of one conglomerate member the sedimentary rocks are fine grained. The volcanic rocks consist of metamorphosed acid and intermediate flows and tuffs. The intermediate rocks are associated with thin bands of slightly metamorphosed limestone, limy shale and greenstones of sedimentary origin. -- A large granite batholith lies along the southern boundary of the map area, and smaller intrusive stocks, sills and dikes, ranging in composition from diorite to micropegmatite also occur. -- No fossils were found in the sedimentary rocks, but by lithological correlation with rocks beyond the thesis area the formations mapped are believed to range in age from middle Ordovician to post-Ordovician. -- It is believed that the rocks were deformed by two major orogenies: one in the late Ordovician, the other late in the Devonian period. The conglomerate member mentioned above may have formed in connection with the late Devonian upheaval. -- The sedimentary rocks have steep dips, generally in a southeasterly direction, but the beds are often overturned. These high dips are indicative of tight, isoclinal folding, and observation of minor folds tends to support this assumption. Faults are not conspicuous, but shearing and brecciation of outcrops in some areas suggest that faulting has taken place in the vicinity of these outcrops. -- The great thickness of the stratigraphic sequence and the abundance of volcanic rocks, some of which show pillow structure, indicate a eugeosynclinal environment. However, most of the sedimentary rocks have characteristics which suggest deposition in a deltaic or terrestrial environment.