identifier: Dillabough, Graham Douglas <https://research.library.mun.ca/view/creator_az/Dillabough=3AGraham_Douglas=3A=3A.html>   (1996) The effects of multiple large scale asperities on deformation and permeability of a single fracture.  Masters thesis, Memorial University of Newfoundland.

abstract: The testing of physical analogues has been shown to be important in the development of theoretical models describing the relationships between fluid flow in fracture systems, and the state of stress and deformation within the host rock of the fracture. The flow and transport characteristics related to fracturing are often enhanced by the effects of the state of stress in the rock walls, which may open up secondary pathways and cause chemical alterations in the wall rocks. -- The objective of this study was to describe the influence of two, parallel, large scale fracture roughness asperities on: 1) the fracture stiffness, displacement and hydraulic transmissivity, 2) the local stress field in the adjacent wall rock, 3) the mode and patterns of secondary fracturing, and 4) the effects on host rock permeability all as a function of changes in both normal and shear stress. The overall study approach included a series of experiments on an instrumented high strength concrete model of a fracture plane in a stiff biaxial loading frame, and comparison of the experimental data with numerical model simulations. -- The concrete model (200 x 200 x 300 millimetres) was cast with 92 strain gauges mounted on concrete coupons embedded along the centre of the model, and 17 manometer ports intersecting the fracture plane to measure the fluid pressures across the length of the model. The fracture plane was formed by pressing an aluminium plate matching the form of the asperities into the wet concrete. This plate was separated from the wet concrete by a piece of geotextile. When the concrete was set, the second half of the model was cast on the geotextile (which was left in place). This geotextile provided the form of a uniform small scale roughness on the fracture surface after the blocks were separated. Four 6.4 millimetre diameter wells were drilled into the top of the model. These wells were used to estimate the matrix permeability changes of the concrete of the model as it was subjected to changing load conditions. -- Results of the study confirmed that the large scale asperities had a significant influence on the local strain field, as seen in the data recovered from the 78 strain gauges that survived the casting and pre-test processes. Three normal and four shear loading cycles showed repeatable internal strain patterns that reflected the effects of the applied boundary conditions. Fracturing in the model was assumed to be caused by tensile stress concentrations at the base of the asperities, and at the ends of the sample. -- Displacement data indicate permanent normal closure of the fracture was greatest for the first normal loading cycle, and decreased over the following two cycles. During the final four cycles, the permanent fracture closure became essentially identical at about 20 per cent of the original closure. This suggests that fracture seating occurred during the first normal loading cycle, which is consistent with other experimental work. -- Fracture transmissivity was seen to decrease logarithmically with the cube root of the normal stress applied to the sample, and decreased further as the sample was sheared, causing closure of the aperture at the large scale asperities. -- The four wells drilled into the top of the model were pressurised with 345 kPa (50 psi) water, and shut in. The pressure decline of each well was monitored sequentially throughout the shear cycles and these data were used to estimate the relative permeability of the concrete. All four wells showed similar decline curves over the periods that each well was monitored. There was no indication that the permeability of the concrete was enhanced by the shear stress applied except by the propagation of secondary fracturing through the wells as the concrete failed. -- The post-test finite element analysis confirmed the assumption that induced tensile fracturing was the primary mode of failure in this experiment. Under normal load, finite element analysis showed that the large scale asperities caused local changes in the orientation of the stress field. Under combined normal and shear load, there were significant tensile stress concentrations associated with the restraining and releasing bends of the fracture, which provided the focus points for the onset of failure of the blocks.


identifier: Thurlow, J. Geoffrey <https://research.library.mun.ca/view/creator_az/Thurlow=3AJ=2E_Geoffrey=3A=3A.html>   (1973) Lithogeochemical studies in the vicinity of the Buchans Massive sulphide deposits, central Newfoundland.  Masters thesis, Memorial University of Newfoundland.

type: Thesis NonPeerReviewed

format: application/pdf application/pdf

abstract: The Buchans orebodies are stratiform massive volcanogenic sulphide deposits associated with calc-alkaline volcanism of probable Silurian age. Since 1928, approximately 16 million tons of ore have been mined with an average grade of 14.97% Zn, 7.73% Pb, 1.37% Cu, 3.73 oz. Ag and .046 oz. Au. The ore is intimately associated with volcaniclastic siltstones and laharic breccias within rhyolitic ash flows. It was deposited in chemically favourable depressions by precipitation of base metals from (sea?)water which was enriched in these components by submarine fumarolic activity during quiescent phases in volcanism. Most of the massive sulphide deposits are underlain by less important stringer and stockwork mineralization which is distinct in both time and space from the major orebodies. -- Two hundred and ninety three chemical analyses of diamond drill core samples for eleven major and fourteen trace elements were performed in order to obtain reconnaissance lithogeochemical data on the volcanic rocks and in an attempt to develop a new exploration technique based on rock geochemistry. The area of study was restricted to a single cross section two miles long by one mile deep containing a representative portion of most lithologic units and three major orebodies. Studies of elemental distributions in the vicinity of the orebodies indicate that dispersion of ore metals is generally restricted to within one hundred feet of the orebodies. Study of lateral elemental variations within lithologic units indicates a broad increase of base metals in most units from northwest to southeast over a distance of about two miles. -- The abundances of Ba, Pb and Zn are distinctly higher in volcanic rocks and sediments related to ore compared to those unrelated to ore. These differences are consistent throughout the entire cross section and are statistically significant at a high level of confidence. Cu, Ag and Hg in some instances are likewise higher in units associated with mineralization. The enrichment of these elements is attributed to a metal-rich volatile phase which accompanied volcanism which produced lithologic units related to mineralization. An expanded geological-lithogeochemical exploration program appears justified on the basis of these results.


identifier: Mosher, David Cole <https://research.library.mun.ca/view/creator_az/Mosher=3ADavid_Cole=3A=3A.html>   (1987) Late Quaternary sedimentology and sediment instability of a small area on the Scotian Slope.  Masters thesis, Memorial University of Newfoundland.

abstract: The Late Quaternary stratigraphy and sedimentation of a small, morphologically smooth region on the Scotian Slope, known as the Verrill Canyon area, has been investigated using high-resolution seismic profiles and piston cores. -- The acoustic stratigraphy in the area has been established with the use of high resolution seismic profiles. Most of the study area is underlain by evenly stratified, coherent reflectors which thin downslope. These reflectors are rooted in outer shelf/upper slope tills and till-like tongues which extend over the shelf break and interfinger with upper slope sediments. Gullies cut the upper slope and a few extend downslope as erosional valleys. Widespread sediment failure has resulted in detachment scarps, slumps, and acoustically-defined disturbed zones. -- Piston cores from undisturbed and erosional zones within the study area provide a composite stratigraphic section over 20 m thick which extends into the Mid-Wisconsinan (approx. 32,000 yBP). Five lithofacies are identified: (1) bioturbated, mottled mud; (2) homogeneous mud; (3) laminated mud; (4) thin-bedded sand; and (5) poorly sorted mud. Hemipelagic, or "no-event" lithofacies comprise about 50% of total sediment cored. Mass-transported sediment, or "event" lithofacies, including fine-grained turbidites and debris flows, comprise the remaining cored material. Synsedimentary deformation features were observed in cores taken from the acoustically identified disturbed zones. -- Wisconsinan sedimentation on the Scotian Slope has been largely affected by glacial events. Processes related to ice margins and lower sea levels served to transport material to the slope. High sedimentation rates and vigorous environmental conditions resulted in abundant sediment failures, producing the event lithofacies. During non-active sedimentation periods, background depositional processes resulted in hemipelagic deposition with abundant bioturbation. The entire study area is covered by a are to two metre drape of fine-grained, bioturbated, Holocene sediment. -- The aocustically-deJfined disturbed zones record the occurrence of a large scale sediment fMlure. Sediment deformation in cores frtxn these failed zones indicates they are ocqposed of a ocrplgx arrangement of slide blocks, vAiich transform'at the distal margins of -the disturbed zones into debrites. Erosionad. scours downslope of "the dlsturbeckt zones^^uggest the^ this sediment failure developed into a large xurbidity current. This failure event was likely seisraically triggered.


identifier: Fleming, J. M. <https://research.library.mun.ca/view/creator_az/Fleming=3AJ=2E_M=2E=3A=3A.html>   (1970) Petrology of the volcanic rocks of the Whalesback area, Springdale Peninsula, Newfoundland.  Masters thesis, Memorial University of Newfoundland.

abstract: Detailed mapping in the vicinity of the Whalesback Mine has established the feasibility of consistently distinguishing two types of metabasalts in a poorly exposed and rather montonous sequence of mainly pillowed volcanics, part of the Lower Ordovician Lush's Bight Group. The two types, called the 'Whalesback' and 'St. Patrick' volcanics, each have a mineral assemblage characteristic of the greenschist facies - albite, epidote, chlorite, actinolite and leucoxene - but are distinguished in the field by their relative abundances of epidote and chlorite, respectively. Intercalated with the flows are discontinuous lenses of pyroclastic rocks. Gabbroic equivalents of the flows are present in dykes, sills and small stocks. The whole sequence is cut by a set of feldspar, amphibole-feldspar, and pyroxene porphyry dykes. -- The poor exposure and the general paucity of primary stratification features make structural analysis very difficult. There is, however, some petrologic indication that the St. Patrick volcanics are stratigraphically above the Whalesback volcanics and the general outcrop pattern suggests an overall anticlinal structure. The area is cut by two major, northeasterly-trending faults, the Davis Pond and Little Deer Pond faults. Minor faulting and shearing has affected all parts of the area but is particularly prevalent in the north block which is also characterized by a relative abundance of porphyritic dykes. -- The Whalesback and Little Deer sulfide orebodies are contained in adjacent, east-west trending shear zones, to the north of and subsidiary to the Little Deer Pond fault. The host rocks are chlorite and chlorite-sericite schists which were derived, at least in part, from pyroclastic rocks. -- A detailed petrographic and chemical study was carried out, concentrating mainly on the flow rocks. Seventeen complete and ten partial chemical analyses were obtained. These show that the Whalesback and St. Patrick volcanics are tholeiitic basalts and basaltic andesites, respectively, that have been affected by metasomatism, mainly addition of soda. The two flow types appear to form part of a differentiation series that is characterized by consistently low potash suggesting a correlation with oceanic tholeiites.


identifier: McCann, Alan Mervyn <https://research.library.mun.ca/view/creator_az/McCann=3AAlan_Mervyn=3A=3A.html>   (1973) Structural and stratigraphic relationships in Silurian rocks of the Port Albert - Horwood area, Twillingate - Fogo districts, Newfoundland.  Masters thesis, Memorial University of Newfoundland.

abstract: The Port Albert - Horwood area is situated in northeast Notre Dame Bay, Newfoundland. It is underlain by five stratigraphic units of probable Early Silurian age. In the southeast of the area the lower part of the stratigraphic succession differs from that of the northwest. -- The lowermost unit in the southeast, the Lower Formation, comprises medium bedded slates and siltstones with some limestone beds. The over-lying Stoneville Formation consists of a Lower, thin - medium bedded, sandy siltstone and slate Member, a Diamict Member mainly composed of thinly laminated beds containing outsize clasts, and an Upper, dominantly sandy siltstone Member. -- In the northwest the Beaver Cove Formation comprises a Lower, thin bedded silt and mudstone Member, a Conglomerate Member containing graded polymict conglomerate and greywacke units, and an Upper, interbedded siltstone and greywacke Member. -- Commonly andesitic, interbedded agglomerates, flows and tuffs of the Port Albert Formation conformably overlie the lower part of the succession in the northwest and southeast of the area. The overlying and uppermost unit, the Dog Bay Formation, comprises a Lower, thin bedded, siltstone Member, a Tuffaceous, massive bedded, sandy siltstone Member and an Upper, medium to fine sandstone Member which disconformably overlies the Port Albert Formation in the northwest. -- Rhyolite and diabase dykes are sometimes composite and intrude rocks of the central part of the area. Rhyolite fragments in the Dog Bay Formation suggest that intrusion was in part contemporaneous with sandstone deposition, and except for a lamprophyre dyke, these intrusions predate the regional deformation. -- Three periods of deformation, of probable Mid-Devonian (Acadian) age, are recognised. The regional, first deformation produced a zonally developed, sub-vertical, penetrative cleavage in association with folding of differing styles. This zonal development may be controlled by a rigid, probably intrusive body close to the surface beneath the central parts of the area. The second and third deformations produced flat-lying and steep kink-bands and crenulations respectively, of the penetrative cleavage and bedding. The Reach Fault is a major, probable strike-slip displacement which parallels, the regional structural trend. West trending tear faults have sinistral and dextral offsets. -- The Diamict Member of the Stoneville Formation is of probable glacio-marine origin and may have been deposited in part by ice-rafting. The Member is compared to similar deposits of Late Ordovician - Early Silurian age which occur in Nova Scotia, Western Europe and Northwest Africa, and to which it may be indirectly related.


identifier: Godfrey, Stephen C. <https://research.library.mun.ca/view/creator_az/Godfrey=3AStephen_C=2E=3A=3A.html>   (1982) Rock groups, structural slices and deformation in the Humber Arm allochthon at Serpentine Lake, western Newfoundland.  Masters thesis, Memorial University of Newfoundland.

abstract: The Humber Arm Allochthon is a well exposed composite allochthon on the west coast of the island of Newfoundland. It extends from the Port au Port Peninsula in the south to Daniels Harbour in the north, and its rocks record the evolution and destruction of the ancient continental margin of eastern North America in early Paleozoic time. -- At Serpentine Lake, the allochthon comprises eight major structural slices and numerous smaller blocks, each enveloped in shaley melange. Transported clastic and carbonate rocks form the structurally lower slices. These are interpreted as rise-prism sediments deposited east of the morphological edge of the ancient continental shelf. The sedimentary rocks are laterally traceable into a regionally extensive melange terrane preserved along the east sides of Blow Me Down Mountain and the Lewis Hills. The melange records tectonic disruption of the alloehthonous sediments and localized olistostromal deposition. A north-dipping sliver of platformal carbonate rocks that lies south of Serpentine Lake records detachment of an upfaulted portion of the collapsing autochthonous terrane during Middle Ordovician (Taconic) emplacement of the allochthon. -- Structurally higher slices contain ophiolitic lithologies and metamorphic rocks related to the evolution and early transport of oceanic crust and mantle. Volcanic rocks structurally beneath the ophiolitic slices are of tholeiitic composition, and formed in the same general tectonic setting. -- Contrasting structural styles within and between slices of the allochthon are attributable to deformational events pre-dating, coeval with, and post-dating allochthon assembly and emplacement. Geological relationships at Serpentine Lake suggest assembly and emplacement of the allochthon through attempted subduction of the North American craton beneath a westward migrating oceanic plate.


identifier: Solomon, Steven M. <https://research.library.mun.ca/view/creator_az/Solomon=3ASteven_M=2E=3A=3A.html>   (1986) Sedimentology and fossil-fuel potential of the Upper Carboniferous Barchois group, western Newfoundland.  Masters thesis, Memorial University of Newfoundland.

abstract: The coal-bearing Upper Carboniferous Barachois Group of western Newfoundland consists of the youngest known rocks in the St. George's Bay Lowlands. These lowlands are part of the Bay St. George Subbasin, which, in turn, is part of a network of Carboniferous depositional areas in eastern Canada. A detailed sedimentological study of the Barachois Group was undertaken as part of a more general study (involving geology and geophysics) to assess the fossil-fuel potential of the western Newfoundland Carboniferous subbasins. -- Cores and exposures of the Barachois Group in the St. George's Bay Lowlands define a lower coarse unit and an upper fine unit. The coarse unit consists of alternating red-brown mudstone-dominated units and grey sandstone and conglomerate-dominated units. The fine unit consists of thick grey or red-brown mudstone-dominated units with interspersed sandstone units. Eleven facies (A to K) are recognized in the two units. The facies are organized into three facies associations and eight subassociations. Facies association I includes fluvial channel sandstones and conglomerates found in outcrops and the BSG£1 core (subassociation IA) and channel and minor sheetflood deposits found in the FB2-76 core (subassociation IB). Facies association II comprises sandstones and mudstones deposited in proximal crevasse channel and levee environments (subassociation IIA), in undifferentiated crevasse splay, levee, and floodplain environments (subassociation IIB), and by progradation of crevasse splay, levee, and delta environments (subassociation IIC). Facies association III includes mudstone-dominated subassociations which represent the deposits of floodplain lakes (subassociation IIIA), poorly-drained swamps (subassociation IIIB), and well-drained swamps (subassociation IIIC). -- Sandstones of the Barachois Group are classified predominantly as arkose and subarkose, with up to 65% feldspar. The sandstones include a variety of authigenic minerals such as kaolinitie, chlorite, illite, calcite, and silica. Sandstone mineralogy does not identify any distinctive provenance. Potential sources of the arkoses could have included several of the presently exposed igneous intrusive complexes in the Long Range Mountains located southeast, east, and north of the study area. -- X-ray diffraction of the <2 micrometer fraction shows that mudstones contain illite, chlorite, kaolinite and mixed-layer clay minerals. Illite predominates in non-grey mudstone; chlorite is the most abundant clay mineral in grey mudstones. Variations in clay mineralogy are due to a combination of initial detrital mineralogy and relative stability of clay minerals through a variety of depositional and diagenetic environments. -- Kerogen types in the Barachois Group are dominated by woody (type III) kerogen with lesser amounts of amorphous and herbaceous types. Thermal maturation indices and kerogen type indicate that mudstones have a fair gas potential, but potential reservoir rocks exhibit poor to fair porosity. Oil shales are lean and coals exhibit considerable variation both between and within seams in terms of ash and sulfur contents. Oil shales and coals appear to be of limited lateral extent and coals are commonly faulted.


identifier: Maher, John Bernard <https://research.library.mun.ca/view/creator_az/Maher=3AJohn_Bernard=3A=3A.html>   (1972) Stratigraphy and petrology of the Pouch Cove - Cape St. Francis area.  Masters thesis, Memorial University of Newfoundland.

abstract: Detailed mapping of the Late Precambrian volcanic and sedimentary rocks of the northeasternmost tip of the Avalon Peninsula indicates that these two rock types are largely penecontemporaneous. This fact will require change or addition to the established stratigraphic column as previously determined by regional mapping. However, the studied area can be adequately described within the framework of the established Harbour Main and Conception Groups, and additional areas should be mapped in detail before new stratigraphic names are introduced. -- The total thickness of sequence mapped in the Pouch Cove - Cape St. Francis area is approximately 2800 meters; its base is not exposed and its top is eroded away or removed by faulting. With the exception of minor folds, the sequence dips to the northwest and represents the northwest limb of an anticlinal zone which passes through Shoe Cove (southeast of the map area). -- For descriptive purposes the sequence is divided into lower middle and upper units of volcanic and sedimentary rocks. These unit divisions have only local descriptive significance and are not proposed as formal entities of stratigraphic nomenclature. Typically the sedimentary units consist of turbidite sandstones with subordinate cherts, shales and conglomerates. Numerous acidic and basic flows and tuffs interlayered with the sediments form the volcanic units. Glacio-marine and tillite deposits within the middle sedimentary unit provide an important stratigraphic marker which is tentatively correlated with glacial deposits known within the Conception Group at several other Avalon localities. Facies differences between correlated localities are related to the volcanic eruptions centered around the Cape St. Francis area. -- Intrusions of quartz diorite, rhyolite and diabase are common in the western part of the area. The quartz diorite which occurs only in the southwestern part of the map area possibly is related to the marginal zone of the Holyrood granite batholith. The rhyolite plugs and dikes postdate the quartz diorite and thus may represent the final stage of activity of a relatively degassed granitic magma. Near Cape St. Francis one such rhyolite flow appears to unconformably overlie inclined strata of the upper sedimentary and volcanic units. If verified by further work such an unconformity would imply late Precambrian deformation, uplift and erosion, possibly related to emplacement of the Holyrood granite. This concept provides an interesting basis for further stratigraphic work in this region.


identifier: Waring, Ronald Anthony <https://research.library.mun.ca/view/creator_az/Waring=3ARonald_Anthony=3A=3A.html>   (1975) Sedimentology of the Bradore formation, southern Labrador, Newfoundland.  Masters thesis, Memorial University of Newfoundland.

abstract: The Lower Cambrian Bradore Formation in Southern Labrador consists predominantly of cross stratified subarkoses, with thin beds of conglomerate and siltstone in the basal part. -- The formation is divisible into two members; the lower, named the Blanc Sablon Member, consists of a basal conglomerate and arkosic sandstones and rests unconformably on a Precambrian basement. Intercalated conglomeratic bands are frequent in the lower beds of this member. Thick to medium bedded subarkoses in the upper beds display isolated lenticular and tabular cross bedding and abundant trough cross stratification. The upper, named the L'Anse au Clair Member, consists of thick bedded quartzose sandstones and thin bedded subarkoses containing worm burrows. Here, cross stratification is less common than in the Lower Member and is mostly lenticular. -- Sedimentary textures and structures indicate that the basal conglomerate was formed by a transgression, probably during the early Cambrian. The purity of the sandstone and the form of its grains suggests deposition of material which has been acted upon for prolonged periods of time, in an environment where currents have restricted the accumulation of silt or grains under a certain size. -- Burrowing structures are extremely common and together with the polymodal orientation of trough cross stratification indicates a shallow water, low energy environment for the subarkoses of the Blanc Sablon Member. The facies of the L'Anse au Clair Member represents a tidal flat or beach deposit.


identifier: Langille, Andrew Benjamin <https://research.library.mun.ca/view/creator_az/Langille=3AAndrew_Benjamin=3A=3A.html>   (1987) Sedimentology and palynology of Cretaceous and Tertiary strata, southeast Baffin Island, Northwest Territories, Canada.  Masters thesis, Memorial University of Newfoundland.

abstract: The geologic history of sedimentary strata exposed off the southeast coast of Baffin Island on Quqaluit. Durban and Padloping islands is poorly understood. A model explaining the environments of deposition and age of these strata is a valuable contribution towards the construction of the geologic history of this region, both in terms of plate tectonics and hydrocarbon exploration. -- By using facies analyses, deposition at the onset of faulting took place in braided streams which was followed by deposition in backswamp regions of fluvial environments, meandering streams, and locally, distal alluvial fans. Volcaniclastic facies are also represented at the upper contact of strata with volcanic basaltic breccia. -- Two miospore assemblages consisting of: Assemblage 1 (dominated by bisaccate pollen, and contains specimen(s) of Distaltriangulisporites perplexus (Singh) Singh, Foveogleicheniidites confossus (Hedlund) Burger, Lycopodiacidites canaliculatus Singh and Cedripites canadensis Pocock among others and woody and coaly debris) and Assemblage 2 (containing specimens of Trivestibulopollenites betuloides Pflug and Pesavis tagluensis Elsik and Jansonius among others and dinoflagelates) are dated as Aptian to latest Albian and Late Paleocene-Eocene, respectively. Dating using paleobotany is supportive of these ages. Assemblage 1 occurs in Durban Island strata, and in strata located below the first volcanic ash and debris flow on Padloping and Quqaluit islands, respectively. Assemblage 2 occurs in strata located in and above the first volcanic ash on Padloping Island and in strata located above the debris flow on Quqaluit Island. -- The vegetation in this small fault-bounded basin appears to be that of a conifer dominated forest. High percentages of bisaccate pollen in the meandering stream complex may indicate a vegetation preference with fluvial style, however, hydrodynamic conditions played an important role in pollen distribution. -- Thermally immature, wood and coal dominate the organic matter in these beds. Therefore, these strata, given a sufficient geothermal history, may source gas and minor liquid hydrocarbons offshore. -- The depositional model indicates that the timing of either initial rifting or crustal attenuation between Greenland and North America was Early Cretaceous. -- KEY WORDS: Sedimentology; Palynology; Facies; Fluvial; Hydrocarbons; Baffin Island; Cretaceous.


identifier: Ostrom, Nathaniel Emil <https://research.library.mun.ca/view/creator_az/Ostrom=3ANathaniel_Emil=3A=3A.html>   (1989) Sources, cycling, and deposition of organic matter in northern Newfoundland fjords and bays.  Masters thesis, Memorial University of Newfoundland.

abstract: An understanding of sources, cycling and deposition of organic matter in northern Newfoundland fjords and bays was gained through the use of stable carbon and nitrogen isotopic and elemental analyses. Seston from terrestrial stations was characterized by two groups: 1) stations which had a dominant influence of runoff had respective average δ¹⁵N, δ¹³C and C/N compositions of 2.2°/oo, -25.5°/oo and 12.3 and 2) stations which appeared to be influenced by freshwater phytoplankton had average values of 5.1°/oo, -24.9°/oo and 8.1 for δ¹³C, δ¹⁵N , and C/N, respectively. A macroalgae endmember was defined by a δ¹⁵N, δ¹³C and C/N of 4.6°/oo, -20.3°/oo and 9.2, respectively. Surface water seston which was not influenced by terrestrial detritus or macroalgae had average values of 8.2°/oo, -24.6°/oo, and 6.5 for δ¹⁵N, δ¹³C, and C/N, respectively, and was considered to be representative of a phytoplankton endmember. -- The isotopic and elemental composition of POM isolated from the water column shifted in response to source, diagenesis and resuspension. Surficial sediments reflected contributions from both macroalgae and phytoplankton and showed little alteration by diagenesis. Degradation was evidenced by loss of organic matter with depth in all sediment cores analyzed. With the exception of one location isotopic ratios were not altered by this process. -- The retreat of the Wisconsinan ice sheet was recorded by variations in the geochemistry of sediment cores. The average δ¹⁵N, δ¹³C and C/N of glacial till collected from the base of one core, 4.3°/oo, -25.3°/oo and 6.0, respectively, indicated a terrigenous origin. This till was a major contributor of organic matter to the lowermost 3 sedimentary units of that core. Shifts in δ¹⁵N from 5.5 to 9.2 °/oo and δ¹³C from -24.4 to -21.8°/oo above these units were related to changes in the relative contribution of phytoplankton and macroalgae. The isotopic and elemental composition of organic matter within Holocene sediments throughout all bays studied indicated a mixture of phytoplankton and macroalgae.


identifier: Schillereff, Herbert Scott <https://research.library.mun.ca/view/creator_az/Schillereff=3AHerbert_Scott=3A=3A.html>   (1980) Relationship among rock groups within and beneath the Humber Arm Allochthon at Fox Island River, western Newfoundland.  Masters thesis, Memorial University of Newfoundland.

abstract: Middle Cambrian to Middle Ordovician sedimentary and igneous rocks comprise three separate structural slices and two distinct melange zones within the southern part of the Humber Arm Allochthon at Fox Island River, western Newfoundland. These overlie a Cambro-Ordovician platformal carbonate sequence in a stratigraphic-structural succession as follows: -- a) autochthonous Lower Cambrian to Middle Ordovician carbonate sequence, with a prominent Middle Ordovician carbonate breccia and shale unit at its top; -- b) autochthonous Middle Ordovician clastic flysch unit; -- c) Basal Melange, consisting of sedimentary blocks in a shaly matrix; -- d) allochthonous Middle Cambrian to Middle Ordovician sediments and structurally associated mafic volcanics which collectively comprise the lowermost slices of the Humber Arm Allochthon; -- e) Medial Melange, consisting of sedimentary, volcanic and gabbroic blocks in a shaly and tuffaceous matrix; -- f) allochthonous Lower Ordovician and older mafic volcanics which form a small medial slice; -- g) allochthonous Upper Cambrian ophiolitic rocks which form the uppermost slice of the allochthon. -- These rocks are covered by Carboniferous sediments and Pleistocene glacial deposits. -- The structural succession is interpreted according to the model of a stable Atlantic-type continental margin destroyed by ophiolite obduction and westerly transport of rock units during the Taconic Orogeny. A three-part history of obduction, uplift and final gravity-sliding is recognized. The components and age of easterly-derived flysch units and the melange zones suggests that during emplacement, the uppermost volcanic and ophiolitic slices began final westward gravity-sliding first, but that the lowermost sedimentary slice assemblage was detached soon thereafter and was first to arrive in the map-area. -- Pre-emplacement deformation consists of metamorphic tectonism within and fragmentation at the base of the ophiolitic slice. Emplacement-related deformation consists of phacoidal melange cleavages and west-facing and verging recumbent folds, which diminish in extent and intensity away from the base of the allochthon. Cleavage in the matrix of the Basal Melange and folds in the uppermost autochthon are shown to be geometrically related. Devonian upright folds which are strongly developed throughout the autochthon, diminish upwards to mild warps in the ophiolitic slice. Post-Carboniferous high-angle faults offset each of the Paleozoic rock units. -- An isolated carbonate sliver at Fox Island River is interpreted as a post-emplacement thrust klippe, though it may be part of the assembled allochthon, incorporated during latest emplacement. -- Volcanic rocks of the allochthon are subalkaline and tholeiitic, and are interpreted as seamounts which grew at or near an ancient continental margin. They were displaced during earliest ophiolite obduction. The volcanic rocks correlate lithologicaliy and structurally with the Skinner Cove Formation of western Newfoundland, although there are significant chemical variations between the rock groups.


identifier: MacLeod, Robert <https://research.library.mun.ca/view/creator_az/MacLeod=3ARobert=3A=3A.html>   (1992) Hydrogeological and geochemical controls on trace metal concentrations in lake sediment in the Holyrood granite.  Masters thesis, Memorial University of Newfoundland.

abstract: A regional lake/pond sediment survey over the Avalon Peninsula in 1976, by the Nfld. Department of Mines, showed a number of lakes with anomalous concentrations of uranium and other metals in the area of the Holyrood Pluton. These anomalies are not reflected in the average host granite rock geochemistry. The hydrogeological framework, including detailed analysis of the fracture systems as major groundwater conduits, has been studied in an attempt to determine the role of groundwaters in transporting and localizing concentrations of trace metals in lake sediment in four lakes in the area. -- Groundwater discharge into the lakes was estimated to range from 20 to 35 percent of their water balances, based on characteristic chemical differences between groundwater and surface waters. Detailed sampling of lake sediment, on a grid pattern, showed a non-uniform areal distribution of metals in these lakes. This sampling also showed that peak concentrations were not restricted to the centres or deepest points in the lakes. The maximum concentration of uranium found in these lakes ranged from 59 to 309 ppm, which is higher than those recorded in the regional survey. In some cases, the elongated shape of the uranium-rich area of sediment is aligned with the orientation of one of the major fracture sets in the study area. Sampling of vertical sediment profiles showed a considerable variation of metals in the sediment column. However there appeared to be no direct relationship between metal concentration in surface sediment and maximum concentrations at depth. Although concentrations of most metals in the sediment are near levels expected for a detrital granite-source origin, anomalous concentrations of uranium at depth in the cores appear to be associated with a rapid change in organic content. A mechanism is proposed whereby mobile dissolved uranium in oxidizing groundwaters is reduced to its tetravalent state when it encounters organic rich mud as it discharges into a lake. The magnitude of seepage flux values and uranium concentrations found in deep groundwaters in the granite suggest that groundwaters are a possible mechanism for the transport concentration of metals in these post-glacial lake sediments.


identifier: Brown, Peter A. <https://research.library.mun.ca/view/creator_az/Brown=3APeter_A=2E=3A=3A.html>   (1972) Structural and metamorphic history of the Gneisses of the Port aux Basques region, Newfoundland.  Masters thesis, Memorial University of Newfoundland.

abstract: Three geological subdivisions are recognized in the Port aux Basques area, the Cape Ray Complex, the Port aux Basques Complex and the Windsor Point Group. The first two are separated by, and the third overlies, the Cape Ray Fault. The Cape Ray Complex is thought to be the oldest division and comprises a gneissic basement intruded by two ages of granite. The gneissic basement, the Long Range Gneiss, is a somewhat homogeneous leucogneiss with basic pods, and has been intensely retrogressed. The early Cape Ray Granite is megacrystic and contains two tectonite fabrics. The later Red Rocks Granite is undeformed. -- The Port aux Basques Complex comprises a series of banded gneisses intruded by the Port aux Basques Granite. These gneisses are complexly deformed and metamorphosed. The second recognised phase is the most intense and is responsible for the dominant composite fabric and gneissic banding observed in the rocks. In general the metamorphism and deformation increase in intensity from west to east as shown by the progressive development of garnet, garnet-staurolite-kyanite, kyanite-garnet, and sillimanite-garnet zones and the development of the migmatite terrain in the Margaree-Foxroost area. The second phase of deformation produced recumbent isoclinal folds with axial planes trending northwest-southeast. The third phase produced upright asymmetric folds trending northeast-southwest. The fourth phase resulted in the crenulation of pre-existing fabrics and open monoclinal folds. The Port aux Basques Granite was intruded after the first and before the second phase of deformation. -- The Windsor Point Group comprises a series of metasedimentary and metavolcanic rocks which overlie the Cape Ray Fault and have suffered three phases of deformation which are related to movements on the fault. These deformations also overprint the fabrics in the Port aux Basques and Cape Ray Complexes. -- The Cape Ray Fault extends for 80 km inland and is of fundamental importance in the structure of the area in that it separates two gneissic complexes of differing age, the older of which was relatively unaffected during the deformation and metamorphism of the younger.


identifier: Weerasinghe, Asoka <https://research.library.mun.ca/view/creator_az/Weerasinghe=3AAsoka=3A=3A.html>   (1970) Stratigraphy and palaeontology of the Ordovician Long Point Formation, Port au Port Peninsula, Newfoundland.  Masters thesis, Memorial University of Newfoundland.

abstract: The Long Point Formation is present in the north-western part of the Port au Port Peninsula, western Newfoundland. It derives its name from Long Point, a northeastward dagger-like extension of the Peninsula fourteen miles in length. The Formation consists of fossiliferous limestones, sandstones and shales that are well exposed in the coastal cliffs on both sides of Long Point. This thesis presents the results of a study of the stratigraphy and palaeontology of the strata underlying the northern half of Long Point. -- On Long Point, beds of the Long Point Formation strike northeast and dip towards the northwest; the dip decreases from 54 degrees at the southern end of the thesis area to less than 10 degrees at the northern end. The beds are little disturbed by the few minor faults present. -- The Long Point Formation has been divided by the writer and two other graduate students from Memorial University working in adjoining areas into eight members, the names of which are taken from their type localities. The members from oldest to youngest are: Tea Cove, Shorepoint, Portage, Black Duck, LeRoy, Beachpoint, Misty Cove and Lourdes. Only those underlined are represented in the thesis area. The lithology of these members is as follows: Black Duck - grey limestones with occasional shaly partings and some argillaceous beds; LeRoy - blue-grey crystalline limestones with shaly partings; Beachpoint - grey, knobbly limestone interbedded with blue shale; Misty Cove - calcareous sandstone interbedded with blue shale. -- The fossil fauna of the Formation as a whole includes brachiopods, bryozoa, crinoids, gastropods, graptolites, ostracodes, scolecodonts, stromatoporoids, tabulate corals and trilobites. Their relationship to particular members is described and an account is given of all the brachiopods and trilobites collected. Of the other groups present, only the more obvious or common representatives have been described. These include one particularly important form, the tabulate coral Labyrinthites chidlensis which has given rise to small columnar reefs in the Black Duck member. The nature of these reefs and other significant, mainly ecological, aspects of the fauna are discussed. -- Details are given of the stratigraphy of the Long Point Formation. The main part of the succession represents the deposits laid down in a transgressive sea. Marine sedimentation was brought to a close by uplift and the nature of the uppermost beds indicates a change in environmental conditions from marine to deltaic or terrestrial. -- Fossil evidence indicates that the strata of the Long Point Formation probably range from upper Middle Ordovician to lower Upper Ordovician in age. (Upper Wilderness to Upper Barneveld Stages).


identifier: Ryan, A. B. (Arthur Bruce) <https://research.library.mun.ca/view/creator_az/Ryan=3AA=2E_B=2E_=28Arthur_Bruce=29=3A=3A.html>   (1977) Progressive structural reworking of the Uivak gneisses, Jerusalem Harbour, northern Labrador.  Masters thesis, Memorial University of Newfoundland.

abstract: The region around Jerusalem Harbour in northern Labrador is composed of a suite of metamorphic rocks of various ages and origins. The Uivak gneisses, containing Saglek dyke and pre-Uivak inclusions, are the deformed and metamorphosed equivalents of an igneous suite emplaced into the crust over 3.6 b.y. ago. Tectonically intercalated with the Uivak gneisses are belts of metasedimentary and basic gneisses known as the Upernavik supracrustals. -- Both the Uivak gneisses and Upernavik supracrustals have been variably migmatized during a period of crustal instability manifested by metamorphism and deformation 3.1 b.y. ago. This 3.1 b.y. event was marked by the generation of a new series of gneisses, herein termed the Iterungnek gneisses. These younger tectonites are a composite, heterogeneous, suite derived both from the remobilization of the earlier Uivak gneisses through a mechanism of structural and metamorphic reconstitution and in situ anatexis, and synkinematic granitic intrusions. In areas where structural reworking has been dominant, the Uivak gneisses can be shown to have undergone progressive transposition until the earlier layering has been completely reoriented and gradually obliterated at the expense of the imposed (Iterungnek) foliation. Where anatexis has been the dominant mechanism, the gneisses show a gradation from lit-par-lit migmatites with Uivak characteristics into Iterungnek nebulites having a granular aspect. The rejuvenation of the Uivak gneisses was synchronous with the intrusion of weakly foliated granitic bodies which gave rise to megascopic agmatite zones where they were emplaced into or adjacent to the Upernavik supracrustals. -- Detailed petrological studies of all the major rock units in the area has shown that the reworking of the Uivak gneisses occurred under granulite facies conditions, which were superimposed on rocks with upper amphibolite facies assemblages. Mineral reactions observed in thin section indicate P-T conditions for the granulite metamorphism to be in the range of 10 kb and 825-850°C, implying a crustal thickness 3.1 b.y. ago on the order of 30 km. -- Regional folds produced during the Iterungnek event are dominantly isoclinal about moderately plunging axes and nearly vertical axial planes. Mesoscopic structures indicate that shearing along the axial planes of tight folds of Uivak gneisses was an active mechanism in the production of the Iterungnek banding. The regional distribution of rock-types is suggestive of refoliation of the Uivak gneisses in synfomnal zones which have been "pinched - in" between more stable border massifs in which little reworking of the older gneiss is evident. It is postulated that this pattern resulted from "collapse" of the crust 3.1 b.y. ago along narrow parallel shear zones due to a softening effect from the build-up of radiogenic heat. -- Even though initial Sr ratios from reworked gneisses in Labrador agree with present theories on Sr systematics in crustal rocks, such is not the case in Greenland. It is suggested that more research is needed into such areas of reconstituted early Archean sialic crust like that in Labrador in order to reconcile the inconsistencies between the observations of the field geologists on one hand and the isotope geologists on the other.


identifier: Hudson, Karen A. <https://research.library.mun.ca/view/creator_az/Hudson=3AKaren_A=2E=3A=3A.html>   (1988) Gold and base metal mineralization in the Nippers Harbour ophiolite, Newfoundland.  Masters thesis, Memorial University of Newfoundland.

abstract: The Nippers Harbour Ophiolite is a southwesterly extension of the lower Ordovician Betts Cove Ophiolite. Extensive sheeted dyke and gabbro members, as well as minor ultramafic components, characterize the Nippers Harbour Ophiolite. The ophiolite is unconformably overlain by the Silurian Cape St. John Group, which consists of subaerial conglomerates, cross-bedded sandstones, basic pyroclastics and andesitic to rhyolitic ash-flow tuffs. The ophiolite also is intruded by the Late Silurian to Early Devonian Cape Brule quartz-feldspar Porphyry. The mafic members of the Nippers Harbour Ophiolite show similarities to Betts Cove boninite-type lavas in that they contain unusually low TiO₂ and high SiO₂, MgO, Cr and Ni contents. -- Mineralization is located commonly in shear or fault zones in mafic ophiolitic rocks. The Hill showing has characteristics resembling those of massive sulphide stockwork zones, with pyrite-chalcopyrite-quartz-chlorite breccia and sheared rock, surrounded by fragments of hydrothermally altered quartz-chlorite-albite rock. Relatively unaltered diabase dykes intrude these assemblages. The altered rocks have been enriched in FeOt, Cu and Zn, and depleted in Na₂O, CaO, Sr and LREE. Mineralization is believed to have been formed by the mixing of upwelling, hot, Fe-, Cu-, Zn-enriched seawater-derived hydrothermal fluids with cold seawater at the diabase-pillow basalt interface. -- Anomalous gold contents have been documented at Burtons Pond, Gull Pond and Showing Number 2. The gold is spatially related to sulphides, mainly chalcopyrite and arsenopyrite, which have precipitated with quartz-calcite, quartz-albite and quartz in veins in altered host rocks. Three alteration assemblages are recognized: (1) quartz-chlorite+/-albite, (2) quartz-chlorite-sericite and (3) quartz-sericite-calcite. Only the Burtons Pond showing displays all three assemblages, whilst the others are associated with assemblage (2). The alteration is expressed chemically by the addition of FeOt, S, K₂O, CO₂, Au, Ag, As, Ba, Co, Cu, Se and Zn, and variable depletions of CaO, Sr and Na₂O. Fluid inclusion and sulphur isotope data (ranging from 4.5 to 6.7 per mil) suggest that the fluids were seawater-derived and had the following characteristics: temperature ~ 250°C, pH 5, total reduced sulphur < 10⁻³M, aO₂ < 10⁻⁴² and aS₂ < 10⁻¹³.⁵. Gold probably was carried predominantly as a thio-complex, but it also may have been a chloride- or thio-arsenide complex. Mineralization is believed to have formed by movement of seawater-derived fluids along shallow thrust planes, depositing sulphides and gold with associated chlorite and sericite, in splays. -- Other sulphide showings include Pb-Zn and Cu-bearing quartz veins at Welshs Bight and Rogues Harbour respectively. Field evidence and sulphur and lead isotope data (-0.4 to 2.9 per mil, and ²⁰⁶Pb/²⁰⁴Pb = 17.659, ²⁰⁷Pb/²⁰⁴Pb = 15.464, ²⁰⁸Pb/²⁰⁴Pb = 37.562 respectively) suggest that these showings are related to the intrusion of the Cape Brule Porphyry.


identifier: Kean, B. F. <https://research.library.mun.ca/view/creator_az/Kean=3AB=2E_F=2E=3A=3A.html>   (1973) Stratigraphy, petrology and geochemistry of volcanic rocks of Long Island, Newfoundland.  Masters thesis, Memorial University of Newfoundland.

abstract: The map area lies at the north of Halls Bay, Notre Dame Bay in the Central Mobile Belt of Newfoundland, i.e., at the northeastern extremity of the Appalachian mountain system. -- The map units consist of a south-dipping, south-facing pile of Ordovician pillow lavas, pyroclastics and volcaniclastic sediments approximately 17,000 feet in thickness. There is a lateral facies change from predominantly pyroclastics with minor lava tongues in the northwest to predominantly lava with intercalated discontinuous lenses of pyroclastics in the southeast. -- The pyroclastics and volcaniclastic sediments are mainly intermediate-composition reworked tuffs with common agglomeratic horizons. There are minor lenses of acid pyroclastics and pseudo-iron formation. -- The flows vary from massive, glassy pillow basalt, crystalline pillow basalt and associated pillow breccia with rare intercalated pyroclastics or sediments at the base to highly vesicular and porphyritic pillowed andesites with numerous and in places thick intercalated pyroclastic lenses. Chemically the flows form two distinct chemical groups corresponding to the stratigraphic level in the pile thus suggesting a general but consistent differentiation sequence from the lower basalts to the upper andesites. The chemistry and stratigraphy suggest that the succession is of island-arc affinity rather than oceanic affinity. -- Each type or group has a mineral assemblage characteristic of the lower greenschist facies epidotite, chlorite, actinolite, calcite, albite; however, the originally igneous mineralogy can generally be recognized. -- A shallowing environment is suggested by the presence of shallow water limestone and limestone breccias and current bedded greywackes near the top of the sequence. However, the recurrence of pillow-lavas and reworked tuffs above this unit suggest either not a completely emergence or a resubmergence. -- The early gabbro, diabase and andesite type intrusions predate the regional, probably Acadian deformation and are probably genetically related to the volcanism. The Long Island pluton and quartz-feldspar porphyries are post-deformation. -- One phase of regional deformation is represented by a locally or zonally developed steep, generally E-W penetrative cleavage. This cleavage is obscured and/or intensified by faulting in the southern area of Long Island. Small scale folds, angular relationships and cleavage-bedding relationships combined with stratigraphic tops suggest that the sequence occupies the south limb of a west plunging anticline. Kink bands fold the earlier fabric but are restricted to fault zones and may be related to faulting. Similarly minor local crenulations of the first cleavage seem to be related to intrusions.


identifier: Pal, Badal Kanti <https://research.library.mun.ca/view/creator_az/Pal=3ABadal_Kanti=3A=3A.html>   (1983) Geomagnetic induction studies in eastern Newfoundland.  Masters thesis, Memorial University of Newfoundland.

abstract: An electromagnetic induction study has been carried out in the period range 40 seconds to 1 second at eight stations in eastern Newfoundland. The results show that conductivity anomalies in the Gander-Avalon zone are mainly associated with geological boundaries and faults. -- Because of the dominance of coast effect in the area, the signature of the inland induction anomaly in the observed data is separated from the superimposed coast effect by applying a difference arrow analysis technique. Difference arrows are obtained by taking a vector subtraction of the analogue model coast effect induction arrows from the observed induction arrows, based on assumption that the mutual inductance between the conducting ocean and any lithospheric conductor is small and can be neglected to a first order approximation. The most important feature apparent from this study is a zone of high conductivity under the Gander-Avalon boundary. -- Two dimensional numerical modelling is used to test models that are compatible with existing geological and geophysical results. A fossil oceanic lithospheric slab remnant from past subduction associated with the closure of the proto-Atlantic ocean is modelled on 25 x 30 grid. Two models, an east-dipping subduction model and an obduction model are shown to be quantitatively consistent with the observations. On the basis of these observations, we are unable to distinguish between these two models. The model of east-dipping subduction places the slab at a depth of 5 km and dipping eastward under the Gander Avalon boundary. The obduction model places the slab at the same depth as the previous model. However, it is extended laterally 28 km into the Avalon zone compared to 22 km as inferred from the previous model. A conductivity of 0.04 s/m which is the typical conductivity of hydrous minerals is determined as the conductivity of the slab.


identifier: Gillespie, Randall Thomas <https://research.library.mun.ca/view/creator_az/Gillespie=3ARandall_Thomas=3A=3A.html>   (1983) Stratigraphic and structural relationships among rock groups at Old Mans Pond, west Newfoundland.  Masters thesis, Memorial University of Newfoundland.

abstract: The Old Mans Pond area is positioned between the Humber Arm Allochthon to the west and the exposed eastern edge of the Appalachian miogeocline east of Deer Lake, thus providing a unique opportunity to study a complete section across the deformed ancient continental margin of eastern North America. The geology of the area demonstrates virtually all elements of the relict margin including, from northwest to southeast: (1) an autochthonous Paleozoic carbonate bank sequence including the well known St. George and Table Head Groups and lesser known Reluctant Head and Penguin Cove Formations; (2) a previously unrecognized allochthonous rise prism clastic sequence (Old Mans Pond Group) which is similar to, and may have at one time been continuous with, the Curling Group of the Humber Arm Allochthon; (3) a newly recognized structural slice (Hughes Lake Allochthon) involving Grenvillian basement rocks (Round Pond Complex) and a thick clastic cover sequence (Mount Musgrave Group) correlative in part with the Labrador Group and Fleur de Lys Supergroup. Carboniferous strata of the Deer Lake Basin overlie older Paleozoic rocks in the area with profound unconformity. -- Structurally the Old Mans Pond area is dominated by an imbricate stack involving the allochthonous assemblages mentioned above. Structural evidence and regional tectonic considerations indicate that the stack was assembled from the east and emplaced against the autochthonous carbonate sequence during the Taconic Orogeny. Deformation was polyphase in nature and westerly time transgressive. Early fabrics which are evident in the transported sequences are not present in the carbonate sequence implying that the carbonate bank was not involved in the earliest stages of the Taconic. Later involvement is evident from the ommission of much of the carbonate sequence beneath the Old Mans Pond Allochthon. -- Subsequent orogenic activity (Acadian?) is responsible for overturning thrusts and fabrics generated during the Taconic, thus producing the marked reversal in structural polarity which characterizes the area. The Acadian Orogeny had little other effect on the area due to its sheltered position northwest of a minor reentrant in the ancient margin. -- The Alleghanian Orogeny evidently had little effect on the area since Carboniferous strata along the western margin of the Deer Lake Basin are undeformed.


identifier: Nixon, Graham T. (Graham Tom) <https://research.library.mun.ca/view/creator_az/Nixon=3AGraham_T=2E_=28Graham_Tom=29=3A=3A.html>   (1974) Late Precambrian (Hadrynian) ash-flow tuffs and associated rocks of the Harbour Main Group near Colliers, Avalon Peninsula, S. E. Newfoundland.  Masters thesis, Memorial University of Newfoundland.

abstract: Late Precambrian (Hadrynian) volcanic rocks of the western part of the Harbour Main Group near Colliers comprise a thick succession of chiefly rhyolitic ash-flow tuffs overlain by basaltic lavas and intruded by porphyritic sills of intermediate composition. The tuffs form three distinct ash-flow sequences, each composed of a number of simple cooling units. The Bacon Cove sequence at the base of the section, the Weavers Hill sequence in the middle, and the Finn Hill sequence at the top, are each characterised by contrasting phenocryst assemblages consisting of albite + quartz + biotite, albite + quartz, and albite + minor quartz and clinopyroxene, respectively. Concentration of crystals and xenoliths near the base of individual cooling units is a direct result of gravitative settling of the suspended load during ash-flow emplacement together with concomitant winnowing of the fine ash fraction. The majority of the Colliers ash-flew tuffs probably represent the distal deposits of a much larger ash-flow field originally situated to the north of the map area. -- Subsequent devitrification and hydration of volcanic glass have preserved vitroclastic textures with remarkable fidelity. The devitrification textures so formed locally resemble structures produced during the experimental devitrification of natural rhyolite glass. -- Mild structural deformation dated as Late Hadrynian and post-Cambro-Ordovician involved block-faulting and two distinct periods of folding and weak penetrative deformation. Metasomatic alteration largely preceded a regional metamorphism of prehnite-pumpellyite grade which may have accompanied Late Precanbrian folding. -- Electron microprobe analysis of feldspar compositions throughout the complete range of Harbour Main volcanic rocks revealed predominantly albite and K-feldspar of metamorphic origin, and rare igneous anorthoclase and calcic plagioclase. -- The chemical effects of alteration processes on the whole-rock analyses have been examined quantitatively where possible prior to classification of magmatic trends and affinities. Localised metasomatism involved mobility of essentially Na₂O, K₂O, CaO, Rb, and Ba. The least mobile constituents are Al₂O₃, TiO₂, total Fe, Zr, Cr, and Ni. -- The silicic ash-flow tuffs and granitoid rocks of the Harbour Main Group are very similar in composition and characterised by high total alkalies, Ba, and K/Rb, and low CaO and Rb/Sr. Ba/Sr and Rb/Sr ratios indicate that plagioclase was precipitated early in the differentiation history of rhyolitic magmas and that biotite was a comparatively late phase to arrive on the Liquidus. The porphyritic sills or "porphyrites" have relatively high K₂O, Ba, and Rb, and low CaO and Sr, and are very similar in composition to continental interior "andesites". The basaltic rocks are "transitional" to "mildly alkaline" chemical types with typically high Al₂O₃ and low TiO₂. The main rock-types of the Harbour Main Group cannot be related simply by fractional crystallisation of a parental silicate melt. -- The accumulated chemical data and prominent bimodal association strongly suggest that the Harbour Main voltanic suite was emplaced in an environment characterised by rifting and distension of continental lithosphere. It is suggested that the ash-flow tuffs and porphyrites originated by partial fusion of the lower continental crust and that the basaltic rocks were derived by partial melting of an upper mantle source region.


identifier: Alley, Douglas Wayne <https://research.library.mun.ca/view/creator_az/Alley=3ADouglas_Wayne=3A=3A.html>   (1975) Drift prospecting and glacial geology in the Sheffield Lake-Indian Pond Area, north central Newfoundland.  Masters thesis, Memorial University of Newfoundland.

abstract: Drift prospecting is defined as the application of glacial geologic, geochemical, geophysical and sedimentological techniques to the problem of mineral exploration in areas mantled by glacial overburden. Glacial drift in the Sheffield Lake - Indian Pond area of north central Newfoundland contains local accumulations of massive sulphide float, grading up to 8.2% Cu. Previous investigations by industry have failed to locate the source of the float. -- The objects of this research were to locate the source of the float by means of drift prospecting, to evaluate the applicability of combined exploration techniques to the glaciated terrain of Newfoundland and to resolve the glacial history of the study area. -- Glacial drift thickness in the area, determined by hammer seismic profiling, varies from 5 to 60 feet. An extensive trenching program revealed the presence of two till units. Till fabric analyses indicated local ice flow directions toward 020 for the Lower Red Till, and either 020-045 (low) or 000-315 (high) for the Upper Grey Till. The sulphide float occurs as first-cycle clasts only in the Lower Red Till and, sparsely, as second-cycle clasts in the Upper Grey Till. The two lodgement tills have been differentiated on the basis of colour, stratigraphy, fabric, texture, pebble lithology, clay mineralogy and geochemistry. The two tills provide the first conclusive evidence of multiple glaciation in north central Newfoundland. -- The sulphide  float, which generally weighs 1-5 lbs., ranges in composition from weakly pyritized and chloritized (host) andesite to massive phyrite-chalcopyrite. Clasts are concentrated in the Lower Red Till where they form a well-defined dispersion fan with the apex pointing toward the southwest. Anomalous concentrations of Cu, Fe, S, Co, and Zn in the Lower Red Till likewise indicate a southwesterly bedrock source of the micro-float dispersion fan. A target area for further detailed exploration of the bedrock source of the float has been delineated on this basis. -- It was determined that the combination of methods employed was essential for delineating the probable source area and it is recommended that they be employed in any future investigations with similar objectives. Of the methods employed, trenching with a backhoe and geochemical analysis of only a restricted size fraction of till samples were found to be particularly valuable. Cu, Fe, and S were found to be the best geochemical tracer elements, particularly when they were mutually associated.


identifier: Dawson, James M. <https://research.library.mun.ca/view/creator_az/Dawson=3AJames_M=2E=3A=3A.html>   (1963) Regional geology of the Topsail-Foxtrap area.  Masters thesis, Memorial University of Newfoundland.

abstract: This thesis is concerned with an area of Precambrian volcanic, sedimentary and intrusive rocks located south of the east side of Conception Bay in the north-central part of the Avalon Peninsula, Newfoundland. Physiographically the region can be divided into a southeastern, gently rolling, plateau-like surface about 600 feet above sea level, and a northwestern sector in which the dominant features are north- northwest-trending ridges and valleys apparently carved by glaciers travelling in this direction. -- The oldest major rock group occurring here is the Harbour Main group which is mid-Proterozoic or older in age. The base of this group is not exposed, however, the visible portion comprises a lower, rhyolitic division and an upper andesitic division, both of which consist of lavas and pyroclasics. To the east of the volcanic rocks lie greenish sandstone, siltstones and cherty sediments of the Conception group, part of which is intertongued with the andesitic rocks of the Harbour Main group. -- The Harbour Main and Conception rocks are intruded by small podlike bodies of felsite, which are particularly prevalent in the zone where andesitic and sedimentary rocks are intertongued. The two main groups mentioned above are intruded by the Holyrood "granite" batholith which consists mainly of adamellite but contains smaller bodies of quartz- feldspar porphyry and aplite. Within the granite an isolated roof pendant of meta-diorite is found. This may be related to the andesites of the Harbour Main group or may represent an older or younger intrusive mass. A small number of basic dikes invade the granite and the Harbour Main group. However, in the rhyolites several sheared basic dikes are found which are possibly older than the granite. -- Lying unconformably upon the granite and volcanic rocks are small, isolated, remnants of interbedded graywacke and slate or shale, herein called the Black Hill sequence. -- Shortly before the emplacement of the batholith, the Harbour Main rocks and intertongued sediments were deformed and subjected to low grade regional metamorphism. This resulted in overall schistosity and cleavage, and in chloritization and epidotization of the andesites. Late plutonic hydrothermal solutions altered the sheared fragmental acid volcanics, in the vicinity of the granite-rhyolite contact, to quartz schist, quartz-pyrophyllite-sericite schist and smaller amounts of almost pure pyrophyllite schist. -- Such folds as can be discerned in the Conception group seem to trend north-northeast and are quite tight, becoming more open to the east. They have probably formed at the same time as the schistosity prevalent in the Harbour Main group as both have the same trend. Folds formed later within the Black Hill sequence have an approximate east-west trend. -- There are many faults in the area, a large proportion of which belong to two sets: (a) north to north-northeast- trending, longitudinal faults and (b) northwest-trending transverse faults. The major longitudinal faults seem to have a diagonal displacement whilst the transverse faults are normal faults. Displacement at most faults is rather small. Most, if not all faults are younger than the Black Hill sequence. The largest of the longitudinal faults, the Topsail Fault, is of post-Ordovician age. -- The main deformations can be placed in two orogenic periods of Precambrian age. The older of these began at some time after the Harbour Main volcanics had been formed and ended with the intrusion of the granite. The later one occurred in post-Black Hill time, folding these rocks as well as other late Precambrian sediments to the east of the area. Apart from some faulting, the rocks do not seem to have been deformed during Paleozoic and younger time. -- The only mining carried out in the area is concerned with the pyrophyllite deposits occurring at Johnny's Pond, about 2 miles south of Manuels. At present, approximately 20,000 tons of 75 per cent-pure pyrophyllite are exported.


identifier: Coates, Howard James <https://research.library.mun.ca/view/creator_az/Coates=3AHoward_James=3A=3A.html>   (1970) Structural and metamorphic history of the Pacquet Harbour - Grand Cove area, Burlington Peninsula, Newfoundland.  Masters thesis, Memorial University of Newfoundland.

abstract: This thesis has no abstract.


identifier: Uzuakpunwa, Anene Benedict <https://research.library.mun.ca/view/creator_az/Uzuakpunwa=3AAnene_Benedict=3A=3A.html>   (1973) Structural studies of the Gander and Davidsville groups in the Carmanville-Ladle Cove areas, Newfoundland.  Masters thesis, Memorial University of Newfoundland.

abstract: The study area lies in the northeastern margin of the Central Mobile Belt of Newfoundland Appalachians. It is underlain by the lower Palaeozoic rocks of the Gander and Davidsville groups, and an older gneissic complex considered a basement to the Gander Group. -- The gneissic basement consists mostly of psammitic banded gneisses and interbedded micaceous quartzites which were unconformably overlain by the Gander group. The latter includes psammitic and semi-pelitic schists, minor conglomerates, greywackes and basic lava flows that acquired a pre-Middle Ordovician composite fabric and a greenschlst to amphibolite facies grade of metamorphism. The Group is separated from the overlying less deformed and metamorphosed sequence of mafic agglomerates, grey slates, interlayered siltstones, minor conglomerates, greywackes and black slates of the Middle Ordovician Davidsville Group by either a melange, ultramafic belt, or a fault. -- Intrusion of the pre-Middle Ordovician garnetiferous muscovite-biotite granites post-dated the development of the composite gneissic banding in the gneissic basement, and predated the first deformation of the Gander Group. A post Middle Ordovician (pre-Devonlan?) quartz diorite intruded the Gander Group, Davidsville Group and the melange. Evidence suggests that the quartz diorite intruded the Davidsville Group before the latter was penetratively deformed. -- The ultramafic rooks of the Gander Group are composed dominantly of pyroxenite, minor chromite bearing serpentinites and talc-carbonate schists which were marginally metamorphosed, and have the same composite fabric as the enveloping metasedimentary rocks. They do not appear to be genetically related to the serpentinized dunite breccia, mafic pillow lavas and hornblende gabbros which were incorporated as blocks in the nearby melange belt separating the Gander and Davidsville Groups. The melange is considered tectonic, having been formed during the upthrusting of the Davidsville Group (onto the Gander Group) as a folded nappe. -- Four main phases of deformation (each producing a fabric) are recognized in the Gander Group, and two other phases (one penetrative), which may or may not be related to those of the Gander Group, are recognized in the Davidsville Group. Evidence suggests that the third deformation of the Gander Group pre-dated the first deformation of the Davidsville Group. The main schistosity in the Gander Group is a second fabric, which has formed by transposition of an earlier one. Tight to isoclinal folds, boudins and interference patterns were produced during the second and third deformations of the Group. A major southwesterly plunging synform, and numerous minor folds were generated during the first deformation of the Davidsville Group. Kink bands and a series of faults offset the regional foliations and are believed to be developed after the main episodes of folding. -- The climax of metamorphlsm in the Gander Group, occurred during the second phase of deformation, producing muscovite-biotite schists, actinolite schists, and amphibolites. A later thermal metamorphic event affected rocks of the Gander and Davidsville Groups.


identifier: Barrette, Paul Dominique <https://research.library.mun.ca/view/creator_az/Barrette=3APaul_Dominique=3A=3A.html>   (1985) Structure and deformational history of the Hawasina Complex in the Sufrat ad Dawh Range, western foothills of the Oman Mountains, Eastern Arabian Peninsula.  Masters thesis, Memorial University of Newfoundland.

abstract: The Semail ophiolite dominates the geological framework of the Oman Mountains and represents the southern extension of a discontinuous belt of ophiolites emplaced oh the eastern edge of the Arabian continental margin In the Late Cretaceous. Its obduction led to the telescoping and emplacement of shelf, slope and basinal sedimentary sequences of Mesozoic age, corresponding to the Hajar Supergroup, the Sumeini Group and the Hawasina Complex, respectively. -- The Sufrat ad Dawh Range is underlain by units of the Hawasina Complex, namely the Hamrat Duru Group and the Wahrah, Al Ayn and Haliw formations. The deformational style in this area is dominated by a regular hinterland-facing imbricate thrust stack. Two sets of imbricate thrust faults are recognized. The faults of the predominant set dip northwards, and are generally parallel to bedding. In the Wahrah nappe, they define an impressive array of connecting, rejoining and diverging splays with minor folding. This set of faults is folded on a macroscopic scale along E-W trending axes, and these folds are, in turn, truncated by steeply northerly-dipping reverse faults belonging to the second set. This second set defines a large-scale re-imbrication system, systematically repeating the Hawasina tectonostratigraphy. Open folding along N-S trending axes occurs in the southern part of the Sufrat ad Dawh Range. -- The tectonic evolution of the Hawasina Complex in the Sufrat ad Dawh Range is divided into three stages. The first stage is an early Imbrication event related to the telescoping of the Hawasina sequenced into separate nappes, and to the tectonic superposition of these nappes in the stacking order generally displayed in the Oman Mountains. The second stage corresponds to the folding of the nappes at distinct intervals across the strike of the allochthons, and with additional shortening In the N-S direction, to the disruption of the limbs of these folds and re-imbrication of the Hawasina nappes. The last stage results either from inhomogeneous compression in the E-W direction, or blending of the nappes over a N-S oriented ramp at depth. 'The timing of deformation cannot be ascertained and several alternatives are presented. The re-imbrication is thought to extend at depth beneath the shelf carbonate sequences of the Hajar Supergroup.


identifier: Gibbons, Rex Vincent <https://research.library.mun.ca/view/creator_az/Gibbons=3ARex_Vincent=3A=3A.html>   (1969) Geology of the Moreton's Harbour area, Newfoundland with emphasis on the environment and mode of formation of the arsenopyrite veins.  Masters thesis, Memorial University of Newfoundland.

abstract: Basic volcanic rocks of Ordovician age near Moreton's Harbour, Newfoundland (pillow lavas, massive flows, and pyroclastic rocks) are intruded by numerous basic and acidic dykes. The rocks are cut by a network of thin veins containing abundant arsenopyrite and some stibnite, associated with pyrite, pyrrhotite, and minor sphalerite, galena, and chalcopyrite. In a few veins, stibnite predominates. Both arsenopyrite and stibnite veins have been mined on a small scale for their associated gold content. The widespread arsenopyrite has been used to determine P-T conditions of formations of the veins, applying the methods of L.A. Clark and A.H. Clark. -- X-ray diffraction analysis of 30 specimens shows that the arsenic content of the arsenopyrite varies between 30 and 34 atomic per cent (d131 spacing from 1.6301 to 1.6338Å.), indicating that the probable temperature range of crystallization extended from about 610°C to 390°C under confining pressures of 1500 bars. -- The hydrothermal veins are related structurally to the acidic dykes (the most competent rock in the area) and genetically to granodioritic intrusive rocks of Devonian age outcropping about five miles east of Moreton's Harbour.


identifier: Tuach, John <https://research.library.mun.ca/view/creator_az/Tuach=3AJohn=3A=3A.html>   (1975) Structural and stratigraphic setting of the Ming and other sulphide deposits in the Rambler area, Nfld.  Masters thesis, Memorial University of Newfoundland.

abstract: The lithologies present in the Rambler Area are described, a sequence of lithofacies units is defined, and a simplistic model to explain the evolution of the rocks in the area is proposed. As a generalisation the rocks dip towards the northeast and become younger in that direction. The base of the sequence consists of basic (Komatiitic) lavas, and this is overlain by basic pyroclastic volcanic rocks. Towards the end of the basic pyroclastic stage a centre of acid volcanism developed, and the sulphide deposits can be related to exhalite activity during the waning stages of acid volcanism. The termination of basic pyroclastic volcanism was followed by deposition of a sequence of basic volcanogenic sediment and/or waterlain tuff, and extrusion of local pillow lava units. Abundant basic intrusions may be contemporaneous with the build-up of the volcanic pile. The volcanic sequence was intruded by the Burlington Granodiorite on the west, and Cape Brule Porphyry on the east. -- All the rocks in the area have been subjected to polyphaser deformation and to metamorphism in the upper greenschist facies. The first two deformation involved intense strain with 1<K<00, and large fold structures were recognized relating to the second and third deformation episodes. The shape and orientation of the sulphide deposits have been modified during deformation; and the ore deposits are elongate parallel to F₂ and F₃ fold axes, and to the Z axis of the deformation ellipsoid. -- The Ming ore body is a Cu, Au, Ag bearing sulphide deposit, and occurs at the top of the acid volcanic rock unit in the area. The settings of the other deposits in the area are also considered and it tis concluded that the sulphide deposits are akin to Archean or Kuroko type deposits.


identifier: Kerr, Andrew <https://research.library.mun.ca/view/creator_az/Kerr=3AAndrew=3A=3A.html>   (1980) Late Archean igneous, metamorphic and structural evolution of the Nain Province at Saglek Bay, Labrador.  Masters thesis, Memorial University of Newfoundland.

abstract: Field and laboratory studies of a group of Late Archean (3000-2700 Ma) gneisses formerly assigned to the "undifferentiated gneisses" of Hurst et al. (1975) provides convincing evidence for crustal reworking in the sense of Moorbath (1975). -- These rocks (for which the term "Kiyuktok gneisses" is introduced) show completely gradational contacts with the 3,500 Ma old Uivak gneisses and range from recognizable derivatives of the earlier suite to structureless nebulites and, ultimately, to coarse-grained intrusive pegmatites containing garnet and orthopyroxene. Even in areas of extensive mobilization, the Kiyuktok gneisses contain remnants of Uivak gneisses and partially resorbed Saglek dykes, which is compelling evidence for derivation from the earlier rocks. The Kiyuktok gneisses are spatially and temporally associated with a group of Late Archean orthogneisses derived from sheets and dykes of tonalite and granodiorite. These are described and correlated lithologically with the Ikarut and Kammarsuit gneisses of the Hebron and Nachvak areas (Collerson, Kerr and Compston, 1980). -- The petrology of Kiyuktok gneisses in various stages of development strongly suggests that they formed by progressive partial melting of the Uivak suite to produce rocks which consist of mixtures in various proportions of relict Uivak "restite" (largely plagioclase) and a Qz-Ab-Or minimum melt. High degrees of melting led to the formation of garnet-bearing granitic (s.s.) magmas, which migrated to higher levels. -- Estimates of physical conditions derived from mineral assemblages in supracrustal rocks by modern geothermometry and geobarometry techniques suggest temperatures of 750-850°C, pressures of 7-9 kb and partial H₂O pressures of 0.2-0.4. These conditions are not sufficient for extensive melting at present levels of exposure, unless substantial introduction of volatiles took place. -- Accordingly, a model is presented whereby melting and reactions at deeper levels leads to dehydration and melting of Uivak gneisses and Upernavik metasediments, producing mobile H₂O -rich melts. Emplacement of pegmatites and granites at the present level of exposure introduced large quantities of water, which caused effectively instantaneous solidus depression and initiated rapid in situ melting under H₂O-saturated conditions. -- Late Archean intrusive rocks, such as the Ikarut and Karnmarsuit gneisses, are interpreted as mixtures of "juvenile” tonalitic and trondhjemitic magma derived by partial melting of a short-lived mafic precursor and enriched granitic melts produced by reworking of the Uivak gneisses via the mechanism above. -- These petrogenetic models for Late Archean crustal development are entirely consistent with isotopic evidence (Collerson, Kerr and Compston, 1980), but do not agree with the models of Moorbath (1975) and Moorbath and Pankhurst (1976) for equivalent rocks in West Greenland. -- The ultimate causes of the Late Archean thermal event which caused reworking are presently obscure. It may relate to crustal subsidence caused by thickening due to overfolding and thrusting during the intercalation of basement and cover prior to 3000 Ma ago, or, alternatively, to the emplacement of mantle derived mafic liquids at the base of the crust.


identifier: Dix, George Roger <https://research.library.mun.ca/view/creator_az/Dix=3AGeorge_Roger=3A=3A.html>   (1981) The Codroy Group (Upper Mississippian) on the Port au Port Peninsula, western Newfoundland: stratigraphy, palaeontology, sedimentology and diagenesis.  Masters thesis, Memorial University of Newfoundland.

abstract: Upper Mississippian sediments of the Codroy Group on the Port au Port Peninsula, western Newfoundland, are remnants of a once extensive cover that mantled a karsted palaeoridge of Cambro-Ordovician strata. Today, the sediment's are patchily preserved within karst depressions, and adjacent low-lying basins. The present topography of the peninsula is, in part, an exhumed Early Mississippian karst landscape featuring a variety of karren, karst valleys and caves. The Mississippian relic karst has been locally rejuvenated. -- Codroy strata constitute three coeval lithofacies: (1) marine carbonates, mainly bioherms, and interbedded fluvial sandstones, (2) marine evaporites, primarily gypsum/anhydrite, with minor, laminated limestone and fluvial elastics, and (3) alluvial-fan conglomerates and braided-stream sandstones. Prograding fluvial and alluvial sediments subsequently buried the marine basins. -- Fauna and sedimentology indicate that the marine sediments were deposited in a schizohaline environment adjacent to a, well-drained landmass. Preserved miospores and plant debris in the limestones, elastics, and gypsum indicate that plants, though not abundant, grew on the slopes of the ridge. Late Mississippian seas along (the northern and western margins of the Port au Port ridge supported a prolific community of brachiopods, bryozoans, blue-green algae, molluscs, and ostracodes. Cephalopods, foraminifers, and conodonts are low both in species and individuals, whereas true corals, and crinoids/echinoids are absent. Fauna traditionally used to differentiate between Upper and Lower Codroy strata are found to occur together within the marine carbonates, but, in two distinct facies. This indicates that the marine macrofauna, and probably microfauna, are facies-controlled prohibiting their use in detailed biostratigraphlc zonation. -- Marine carbonates infilling palaeokarst valleys may constitute either bryozoan/algal biolithites plastered against the valley walls and/or carbonate mounds of a similar lithology, with associated intermound sediment. The buildups were lithified early as evident by the abundant synsedimentary cement (interpreted to have been magnesium, calcite and aragonite). -- The complex diagenetic history of the marine carbonates records progression from a marine environment with synsedimentary cementation to a phreatic zone within which occurred fracturing,  stylolitization, dissolution and cement precipitation. Mineralization by sulphides and sulphates spans the phreatic diagenetic history. Late stage phreatic cement is pervasive in all other sediments of the carbonate lithofacies as well as throughout the carbonate and clastic sediments of the other lithofacies.


identifier: Pitman, David John <https://research.library.mun.ca/view/creator_az/Pitman=3ADavid_John=3A=3A.html>   (1991) Taxonomy of Ordovician ostracodes from western Newfoundland, Anticosti Island and the St. Lawrence Lowlands of Québec.  Doctoral (PhD) thesis, Memorial University of Newfoundland.

abstract: The results of an investigation of Middle and Upper Ordovician ostracodes from southeastern Canada are reported. Sixty-two samples were collected from the Table Head and Long Point groups, western Newfoundland, the Jolliet Group, Anticosti Island, and the Trenton Group, St. Lawrence Lowlands. These yielded over 2600 moderately to well-preserved ostracodes. The Carter Collection, an existing collection of ostracodes from the Lowlands, was also examined. During the research, a series of difficulties were encountered in obtaining the faunas, interpreting their taxonomy, and understanding their paleoenvironmental implications. -- In the sections studied, Ordovician ostracodes occurred sporadically and were often rare or absent. All the collections were obtained by washing soft shales or by vibra-tool preparation of indurate limestones; selection of samples that can be readily processed is essential. Ordovician ostracode taxonomy is often confusing; many species are narrowly defined and allow little morphological variation. In this study, the taxonomy of a number of species is revised and a number of existing species are re-interpreted as synonyms. Fifty-four species representing forty genera are described and illustrated. No new species are established, because the current species are either already described in the literature, or could only be identified at the generic level because of a lack of well-preserved material. -- Although faunal composition, abundance and diversity arc directly influenced by the paleoenvironment, it is difficult to develop ostracode-based criteria for the elucidation of Ordovician paleoenvironments. Observations made during this study indicate that sea-level changes and water depth were strong controls on the nature of Ordovician ostracode faunas. In the Lourdes Formation, western Newfoundland and the Ellis Bay Formation, Anticosti Island, marked increases in faunal diversity and the rates of speciation can be directly correlated with transgressive events that increased the shelf area and the variety of niches available. Water depth, through its control of a variety of interdependent ecological factors, such as water temperature, food supply and substrate, was also an important influence on the type of ostracode community present. A series of depth-related communities are tentatively recognised. High- energy, nearshore environments tend to have a high-abundance, low-diversity fauna consisting of large, robust, smooth ostracodes; speciation rates are low and the community structure is relatively stable. Stable, open shelf, carbonate environments tend to have high-diversity faunas, consisting of a wide variety of ornamented forms such as Eurychilina subradiata and Foramenella phippsi; speciation rates are high and the community structure frequently changes. Outer shelf to shelf-slope environments tend to have a low-diversity, low-abundance fauna consisting of drepanellids such as Warthinia nodosa and smooth-elongate ostracodes like Phelobythocypris cylindrica; speciation rates are low and the community structure is stable. As depth increases and the shelf-slope transition is crossed, faunal abundance and diversity diminish rapidly and in situ ostracode faunas disappear altogether. -- Effective use of Ordovician ostracodes as biostratigraphic indicators, depends on their ability to cross facies and provincial boundaries. At present it is not possible to make more than crude correlations, because the faunas are not well enough known. A few of the species, such as Eurychilina subradiata and Tetradella quadrilirata, are wide ranging and have obvious potential for correlating Ordovician shelf sediments. Many other species cannot be used for inter- or intra-regional correlation, because they are locally endemic, occurring in some areas, but not in others.


identifier: Pulchan, K. Jerry <https://research.library.mun.ca/view/creator_az/Pulchan=3AK=2E_Jerry=3A=3A.html>   (1987) Organic geochemical comparisons of Fortune Bay and Bay d'Espoir.  Masters thesis, Memorial University of Newfoundland.

abstract: Fortune-Bay and Bay D'Espoir are two fjords in close proximity, yet with contrasting internal properties and processes. Samples from six cores from Bay D'Espoir and five cores from Fortune Bay were analysed for organic carbon and nitrogen content, δ¹³C, δ¹⁵N, and total and individual amino acids. The δ¹³C values for Bay D'Espoir samples were relatively lower than those for Fortune Bay, indicating a stronger influence of a terrigenous source in Bay D'Espoir. The δ¹⁵N values were constant (7-8°/oo) for all cores except for cores BDE-1643 and BDE-1657, which were strongly depleted in ¹³C and ¹⁵N. The δ¹⁵N and the amino acid signatures delineate a predominantly macrophytic source of organics within both bays. Productivity levels were reflected in the percent organic carbon and total amino acid abundances which were higher in Fortune Bay samples than those in Bay D'Espoir samples. There is a general decrease in percent organic carbon and total amino acids with depth. The magnitude of this trend varies with each core. In cores FO-840404 and FO-840405 the trend may be related to a change from modern marine sedimentation to glaclomarine sedimentation. The change in sedimentation pattern is also reflected in the fraction greater than 63µ, foraminiferal count and ¹⁸O abundances of the foraminiferal carbonate tests. Finally, the D[AILE] / L[ILE] indicated higher sedimentation rates in Bay D'Espoir than in Fortune Bay.


identifier: Marten, B. (Brian Ernest) <https://research.library.mun.ca/view/creator_az/Marten=3AB=2E_=28Brian_Ernest=29=3A=3A.html>   (1971) The geology of the Western Arm Group, Green Bay, Newfoundland.  Masters thesis, Memorial University of Newfoundland.

abstract: The Western Arm area is underlain by mafic volcanic rocks of early Ordovician age, comprising the Lush's Bight Group succeeded conformably by the Western Arm Group. The Lush's Bight Group is composed of monotonous altered pillow basalts of great but unknown thickness. The study shows that the alteration, which dies out at the top of the Group, is an early event probably related to inherrent heat in the volcanic pile. The Western Arm Group, defined in this study, consists of a lower tuff formation, a middle pillow basalt formation and an upper formation comprising a lower tuff, and an upper agglomerate member. The tuffs are waterlain and include basic, intermediate and dacitic varieties with interbedded slump-breccias and minor chert and argillite horizons. -- Intrusion of gabbroic sills and a small quartz diorite pluton pre-dated a regional deformation. Evidence suggests that the intrusive rocks form a suite genetically related to the volcanism. -- A sub-vertical penetrative cleavage is zonally developed in the lower part of the succession but dies out below the middle of the Western Arm Group. A series of sinistral faults are sub-parallel to the cleavage and are believed to have developed during the folding. Folds are on a large scale, and the Western Arm Group is inferred to lie on the south limb of a major ENE-trending syncline. Metamorphism related to the folding was mainly limited to growth of chlorite and fibrous amphibole on the cleavage planes. -- Two major dextral wrench faults post-date the folding, and may be related to the Birchy Lake fault and the Cabot fault system. -- Comparison with other areas suggests that the Western Arm Group may be correlated with the Cutwell Group and with the Snooks Arm Group.


identifier: Gall, Quentin <https://research.library.mun.ca/view/creator_az/Gall=3AQuentin=3A=3A.html>   (1984) Petrography and diagenesis of the Carboniferous Deer Lake Group and Howley Formation, Deer Lake subbasin, western Newfoundland.  Masters thesis, Memorial University of Newfoundland.

abstract: The Deer Lake subbasin is one of two northeast-trending, mainly Carboniferous, subbasins in western Newfoundland. Within the subbasin the Deer Lake Group and Howley Formation consist entirely of non-marine sediments deposited in a half-graben which was extensively faulted along its eastern side. Petrographic investigation of nine drill cores has shown that coarse grained alluvial fan and fluviatile sediments from the North Brook, Humber Falls, and Howley Formations, and high-grade uranium-mineralized sandstone boulder samples found in Pleistocene tills above the northern body of the Humber Falls Formation, have essentially the same detrital and diagenetic mineral assemblage and display the same paragenetic sequence. The dominantly lacustrine siliciclastic and carbonate sediment samples from the Rocky Brook Formation have a mineral assemblage and paragenetic sequence different from the coarser grained formations. Basic mineralogic differences are the absence of diagenetic kaolinite and illite-montmorillonite, and the presence of "analcime" in the Rocky Brook Formation sediments. The paragenetic sequence for the North Brook, Humber Falls, and Howley Formations and the mineralized samples reflects an acidic to alkaline geochemical environment. The paragenetic sequence for the Rocky Brook Formation on the other hand appears to have developed within a more stable alkaline geochemical environment. Correlating paleomagnetic data with the derived paragenetic sequence for the three coarse grained formations suggests that the sequence took more than 40 Ma to completely develop. A postmineralization episode of hematite cementation may mean that economic quantities of uranium no longer exist in the sandstones. -- High-volatile bituminous B and C coaly material and diagenetic clay mineral assemblages extracted from the drill core samples suggest that the sediments remained within the diagenetic realm after deposition, and that maximum temperatures between about 125ﾟ C and 135ﾟ C were attained during coalification and authigenic clay growth.


identifier: Levesque, Rene Joseph <https://research.library.mun.ca/view/creator_az/Levesque=3ARene_Joseph=3A=3A.html>   (1977) Stratigraphy and sedimentology of Middle Cambrian to Lower Ordovician shallow water carbonate rocks, western Newfoundland.  Masters thesis, Memorial University of Newfoundland.

abstract: Detailed lithostratigraphic analysis and new fossil data have resulted in a revised and refined stratigraphic and sedimentologic framework for the autochthonous, Middle Cambrian to Lower Ordovician, shallow water sedimentary sequence in western Newfoundland. Study of five separate localities, spanning a distance of 285 km., indicates that much more of this 900 metre thick sequence Is of Cambrian age and much Less of Ordovician age than previously reported. -- The oldest units studied are of late Lower Cambrian age and can be recognized in three of the five localities where they are named the Degras Formation (at the Port-au-Port Peninsula), the Penguin Cove Formation (at Goose Arm), and the Hawke Bay Formation (at Bonne Bay). These thick-bedded, supermature, quartzose sandstones are interpreted to have formed as a system of barrier bars or beaches. -- An overlying succession of distinctive. Middle and Upper Cambrian, limestones, dolostones, and shales is recognized from Port-au-Port in the south to Hawkes Bay in the north. This succession is variously known as the March Point (revised) and overlying Petit Jardin (revised) Formations at Port-au-Port, the Wolf Brook (proposed) and overlying Blue Cliff (proposed) Formations at Goose Arm, the South Head (proposed) and overlying East Arm (revised) Formations at Bonne Bay, and the upper Hawke Bay Formation at Hawkes Bay. -- Middle and Upper Cambrian rocks are characterized by conspicuously cyclic, "high-energy" lithofacies and comprise two large scale sequences which repeat, in vertical succession, as many as three times: (I) thin-bedded sequences composed of flaser bedded limestone and shale intercalated with occasional beds of edgewise conglomerate, stromatolites, and oolite, interpreted as a mixed carbonate-sillciclastlc tidal flat and (2) thick-bedded sequences composed of intraformational conglomerate, in places oncolitic, cross-bedded oolite, and laminated, mud cracked calcilutite, interpreted as carbonate sand shoals or barrier islands. -- The succeeding Lower Ordovician St. George Formation (revised) is recognized along the length of western Newfoundland and is divided into three members: the lower cyclic member, of interbedded limestone and dolostone, the middle limestone member, a thick limestone unit locally overprinted by epigenetic dolomitization, and the upper cyclic member, of interbedded limestone and dolostone. Thickness of the St. George is about 550 metres, greatly reduced from previous estimates. -- A disconformity that dies out to the north separates the St. George from the overlying basal limestone of the Middle Ordovician Table Head Formation. -- Lower Ordovician lithofacies are characterized by "low energy" subtidal features, with few diagnostic intertidal features, and comprise two megarhythms: (1) carbonate cycles grading from burrowed, fossiliferous, subtidal limestone to microcrystalline, laminated, occasionally mud cracked, supratidal dolostone, interpreted as shoaling upward cycles on a protected tidal flat and (2) burrowed, fossiliferous, hackly weathering, subtidal limestone, representing deposition in a protected lagoonal environment. -- These rocks record a major marine transgression and may reflect a change in the form of the shallow water continental margin from a ramp or open shelf in the Cambrian to a mound-rimmed carbonate platform in the Ordovician. Superimposed on this major transgression are as many as five smaller transgressive/regressive events.