identifier: Butt, Stephen Douglas <https://research.library.mun.ca/view/creator_az/Butt=3AStephen_Douglas=3A=3A.html>   (1994) A physical and numerical model study of the state of stress and deformation associated with large scale fracture roughness.  Masters thesis, Memorial University of Newfoundland.

abstract: The focus of this research study was to quantify the influence of a single large scale fracture roughness asperity on the fracture stiffness and displacement, the local stress field in adjacent wall rock and on the mode and patterns of any induced secondary fractures under various states of applied stress. This was accomplished through the use of a discrete fracture numerical modelling code and experiments on an instrumented high strength concrete model of a fracture plane in a stiff biaxial loading frame. -- Initial numerical modelling was completed to determine a suitable asperity morphology for the physical model. Laboratory experiments were conducted on test specimens to determine the material characteristics of the intact concrete and the simulated fracture for input into the numerical model and to measure the 0 to 40 kHz acoustic emission signature of induced fracturing. Nonlinear numerical modelling was completed to predict internal stresses in the concrete model during two normal and two shear loading cycles and to predict modes and patterns of secondary fracturing. The concrete sample was subsequently tested under three normal and three shear loading cycles. Strain gauges cast into the concrete model measured the internal strain field. Displacement transducers mounted on the model measured average fracture displacements and an accelerometer monitored acoustic emissions. The sample macroscopically failed at the peak of the final shear loading cycle and was impregnated with a low viscosity resin to enable "post mortem" analysis of secondary fracturing. -- Results of the study confirmed that the large scale asperity had a significant influence on the local stress field and that several forms of enhanced fracture porosity were associated with plastic and brittle deformation near the asperity. Comparisons between the numerically predicted and experimentally measured stress fields showed that the uniformity of fracture mating about the asperity and secondary fracturing significantly influenced the measured strain field and the accuracy of the numerical predictions. Finally, measured patterns of induced secondary fracturing were very similar to those predicted from results of the numerical modelling.


identifier: Webb, Susan Jane <https://research.library.mun.ca/view/creator_az/Webb=3ASusan_Jane=3A=3A.html>   (1992) Axisymmetric inertial gravity oscillations of a compressible stratified fluid in a rigid sphere : an approximation of the Earth's outer core.  Masters thesis, Memorial University of Newfoundland.

type: Thesis NonPeerReviewed

format: application/pdf application/pdf

abstract: This thesis investigates several theoretical methods for solving the sub-seismic wave equation (SSWE) in an incompressible or slightly stratified liquid bounded by a rigid fixed spherical boundary as an approximation to the Earth's liquid core. The solution of the SSWE yields eigenvalues for the inertia/gravity wave spectrum. The first method considered uses a variational principle based on a more general functional than has been previously used to evaluate the SSWE. The resulting eigenvalues are compared with previous work done by Aldridge and Toomre (1969). The work is then extended to include a density profile and a shift is noted in the eigenspectrum. A perturbation approach was used to include stably stratified regions characterised by negative values of the stability parameter B; unfortunately this method only works for such small values of B as to be uninteresting. Finally a Galerkin approach was adopted that allows for the evaluation of negative B values. This results in a further change of the inertial eigenspectrum and the appearance of gravity modes.


identifier: Otterson, Timm <https://research.library.mun.ca/view/creator_az/Otterson=3ATimm=3A=3A.html>   (1992) An analysis of the wind-forced response of Conception Bay using a reduced-gravity numerical model.  Masters thesis, Memorial University of Newfoundland.

abstract: A reduced-gravity numerical model of Conception Bay, Newfoundland, with a realistic coastline and driven by local wind is developed to analyze the wind-forced response of the pycnocline. Model solutions are compared with temperature and current measurements collected from sub-surface moorings deployed at the month in the spring of 1989 and near the head in the spring of 1990. The observed temperature near the head shows similar behavior at all six moorings indicating upwelling of the pycnocline due to northeastward winds. Upwelling around the head and evidence of phase lag from one mooring to the next are consistent with Kelvin wave propagation. The model reproduces most of this variability at all six moorings including the two moorings on the eastern side of the Bay near Bell Island Tickle where Kelvin waves might be expected to be scattered by bottom topography. At the mouth, only the 2 day temperature signal at the mooring closest to the western shore is successfully reproduced by the model. The model's ability to better reproduce temperature variability at the head is explained by the increased wind-forced response at the head and the likely importance of external forcing at the mouth, either from Trinity Bay or due to eddies entering the Bay from outside. The current field at both the head and mouth is poorly reproduced by the model, probably due to the complicated vertical structure of the current. Coherence analysis of the current data shows that the horizontal scale of coherent motions is small (less than 10 km). -- In developing the model used for comparison with observations, boundary conditions that allowed an accurate solution were developed. Placing a radiation condition perpendicular to the coast "upstream" of the Bay resulted in the generation of spurious fluxes and near-inertial Kelvin waves at the boundary. These problems were eliminated by extending the coastline out to sea on the "upstream" side of the mouth and applying a condition of zero normal gradient in interface displacement on the artificial stretch of boundary. Experiments using sponge layers rather than radiation conditions on the other boundaries showed that sponging only the interface displacement and leaving the velocities undamped gives results that compare well with those obtained using radiation conditions. Sponging the velocities as well as the interface displacement led to significantly different results suggesting that applying highly viscous layers around open ocean parts of model boundaries can be counter-productive.


identifier: Lu, Youyu <https://research.library.mun.ca/view/creator_az/Lu=3AYouyu=3A=3A.html>   (1994) A fine-resolution barotropic model of the North Atlantic driven by wind and atmospheric pressure forcing.  Masters thesis, Memorial University of Newfoundland.

abstract: We investigate the response of the North Atlantic to wind and atmospheric pressure forcing with a two-dimensional, fine-resolution barotropic model. The model domain extends from the equator to 65ﾟN and from 100ﾟ W to 14ﾟE with a resolution of 1/3ﾟ in latitude and 2/5ﾟ in longitude. The forcing field to drive the model is the twice-daily wind and atmospheric pressure data from the European Center for Medium Range Weather Forecasts (ECMWF). The model results are compared with sea level observed at coastal tide gauges, volume transport derived from voltage measurements made using a submarine cable across the Florida Straits, and bottom pressure data collected on the Labrador and Newfoundland Shelf. The time scales being studied range from several days to seasonal. -- The primary model experiment is a two-year (1985-1986) run driven by both wind and atmospheric pressure forcing. Three one-year runs are used to determine the contributions from the individual forcing, and the influence of Hudson Bay on the Labrador Shelf. Model results show the best agreement with observed sea level data at locations with broad shelves where the stratification is weak. Significant coherence between observed and modeled adjusted sea level is obtained at periods beyond ~3 days, at four representative stations along the western boundary. Contributions from atmospheric pressure forcing are not important for periods beyond ~2-3 days. The primary model experiment explains the observed volume transport variation through the Florida Straits at synoptic time scales, which is mainly due to wind. The model captures the variation at longer time scales in 1985, but not in 1986. The exclusion of advection by the mean flow may be the reason for the drop of coherence at ~10 days in the case of the Florida Straits volume transport and at ~12 days in the case of sea level at Fernandina Beach, Florida. -- Model output is also coherent with the observed bottom pressure data from the Labrador and Newfoundland Shelf. The significant non-iostatic response in the observational data at synoptic time scales in reproduced by model experiments with the Hudson Bay-Hudson Strait system included, with energy peaks at ~2-6 days. The contribution from atmospheric pressure forcing is only important in generating the energy peak at ~2-6 days when the Bay/Strait system is included, verifying the Helmholtz-like resonance mechanism proposed by former researchers. Wind forcing dominates over atmospheric pressure forcing at synoptic time scales. In particular, the wind over Hudson Bay-Hudson Strait is shown to be important.


identifier: Brown, Dennis Lewis <https://research.library.mun.ca/view/creator_az/Brown=3ADennis_Lewis=3A=3A.html>   (1990) A structual analysis of the Grenville Front Zone, Northeast Terrane, Labrador.  Masters thesis, Memorial University of Newfoundland.

abstract:
The study area, located in western Labrador near the projected intersection of the front zones of the Grenville and Hudsonian orogens, occupies part of Gagnon terrane in the Parautochthonous Belt of the Grenville Province. Rocks in the area consist principally of supracrustal units of the Early Proterozoic Knob Lake Group, and a newly recognized, tectonically overlying unit, the Equus Lake formation, both of which are intruded by Middle Proterozoic gabbros of the Shabogamo Intrusive Suite. -- The structural elements in the rock units record evidence of a polyorogenic history that is attributed to NW-trending structures of the ca. 1800 Ma Hudsonian orogeny that were overprinted by NE-trending structures of the ca. 1000 Ma Grenvillian orogeny. -- Grenvillian deformation and metamorphism resulted in the formation of a relatively deep level, north-verging foreland fold and thrust belt. Four structural domains have been defined based on variations in morphology and orientation of structural elements, and internal domain geometry. Each domain is interpreted to be a structurally distinct thrust bound unit or group of units that has
undergone a unique deformational history. The map pattern indicates a complex stacking order of the domains, and of thrust slices within domains, that involved development of northwest- to north-directed fold nappes followed by out-of-sequence thrusting. -- Metamorphic grade varies from lower to upper greenschist facies. Plagioclase-amphibole geothermometry shows qualitatively that there is an increase in Grenvillian metamorphic grade from northwest to southeast across the area. Quantitative garnet-biotite geothermometry indicates that the Grenvillian metamorphic grade attained temperatures of 450 ﾟC in the southern part of the area. Inversion of temperature with structural height in the thrust stack is a well known feature from higher level thrust stacks and implies thrusting post-dated the metamorphic peak. -- Documentation of the northern margin of Gagnon terrane as a NW-directed metamorphic fold and thrust belt corroborates similiar interpretations from elsewhere along the Grenville Front, and is in accord with the models of the Grenville Province as a collisional orogen.


identifier: Kristjansson, Leo Geir <https://research.library.mun.ca/view/creator_az/Kristjansson=3ALeo_Geir=3A=3A.html>   (1972) A magnetic study of tertiary igneous rocks from Greenland, Baffin Island and Iceland.  Doctoral (PhD) thesis, Memorial University of Newfoundland.

abstract: This work describes paleomagnetic measurements carried out by the author on rock samples from Tertiary basalt areas in southern Disko Island (West Greenland), Cape Dyer (Baffin Island) and Iceland. -- In the Disko collection, the stable remanence direction of samples from 45 felsparphyric lava flows in three separate profiles was measured and shown to be that of the primary remanence in the flows. A mean ancient pole position at 62°N, 169°W was derived from 37 of these flows. A relatively large secondary component of remanence was shown to be viscous remanence acquired in situ during the present geomagnetic epoch. Correlations between these magnetizations and other magnetic characteristics of the flows were studied. -- The magnetic properties of several intrusive basalt units, a breccia, and local sediments, all from Disko Island, were also investigated. All formations were found to be reversely magnetized, but differences in these properties between and within the units were shown to be due to variations in oxidation state and in the rate of initial cooling. -- Similar studies were carried out on samples from 6 olivine basalt flows in Cape Dyer. Their remanence was very stable and of normal polarity; secondary magnetization components are small except in three samples from one flow, which are reversely magnetized and appear to have suffered remagnetization in situ, A mean pole position of 83°N, 55°W was derived from five of the Cape Dyer flows. -- Various magnetic properties of a number of rock samples from Iceland and from the Precambrian basement on the Baffin Bay coast were investigated, to aid in the geological interpretation of magnetic anomalies found in these areas. -- Two rock magnetic instruments, a thermomagnetic balance and a ballistic magnetometer, were designed, built and used during the present study and are described in detail.


identifier: English, Gerald Michael <https://research.library.mun.ca/view/creator_az/English=3AGerald_Michael=3A=3A.html>   (1995) A novel vibrating-sample magnetometer used to measure magnetic hysteresis of rock at low temperature.  Masters thesis, Memorial University of Newfoundland.

abstract: A vibrating-sample magnetometer was constructed, calibrated and used to measure the magnetic hysteresis of rock samples. The magnetometer was designed around a large electromagnet capable of producing fields of approximately 3600 Oe (360 mT). Between the poles of this magnet, pick-up coils and a liquid nitrogen bath surrounded a sample port assembly in which the sample could be vibrated. The sample port assembly contained a heating element that allowed the sample temperature to be varied from room temperature to 98 K (-175ﾟC). A novel method was used to vibrate the large (5 gram) rock samples. The sample was mounted off-axis on a rotating shaft in a way that kept the sample's orientation in the applied field from changing while the sample moved uniformly in a circle of 2 mm radius 29.2 times a second. This induced a 29.2 Hz sinusoidal voltage in the pick-up coils proportional to the magnetization of the sample. Cycling the magnetic field intensity allowed hysteresis loops to be automatically plotted. -- Seven magnetite-bearing Precambrian dolerite dyke samples which had likely retained their original remanence direction for over a billion years were studied. Measurements of their magnetic hysteresis as a function of low temperature were used to investigate what mechanisms allowed them to retain such stable remanence. -- The coercive force, Hc, of the samples decreased as a linear function of saturation magnetostriction on cooling. This suggests that internal stresses opposing domain wall motion are mainly responsible for the ability of most of these rocks to retain stable remanence. The one clear exception was the specimen of highest coercive force (Hc = 487 Oe = 3.9x10⁴ A/m) in which Hc hardly changed on cooling suggesting that remanence was carried by single-domain grains with shape anisotropy. -- The ratio of saturation remanence to saturation magnetization JR/Js was found to change linearly with saturation magnetostriction and with coercive force on cooling. These linear relationships and that between coercive force and saturation magnetostriction were used to infer what proportion of the magnetite present was in the form of single-domain or pseudo-single-domain grains using the method of Hodych (1990). This method could not be applied to the sample of highest coercive force because its coercive force and saturation remanence did not change on cooling. -- Reversible work, Wrev, done on descending from saturation to the remanence point in a hysteresis loop was measured as a function of low temperature. When Wrev was estimated by integrating to a constant magnetization rather than to a constant field, Wrev was found to decrease on cooling. However, this does not allow inference of what is controlling domain rotation in the samples.


identifier: Bridge, Colleen <https://research.library.mun.ca/view/creator_az/Bridge=3AColleen=3A=3A.html>   (2004) Structure and salt tectonics of Messinian evaporites in the Cilicia Basin, eastern Mediterranean.  Masters thesis, Memorial University of Newfoundland.

abstract: During the Oligocene to late Miocene, the Cilicia Basin evolved as a foreland basin in front of the Taurus Mountains thrust front. Over time, the regional eastern Mediterranean tectonics, the continual subsidence of the Cilicia Basin and the rapid progradational loading of the evaporite unit by sediments from the northeast end of the Cilicia Basin (the Adana Basin) have resulted in the development of three tectonic domains within the basin. -- A particular type of faulting and salt tectonism characterizes each tectonic domain. The inner domain consists of salt rollers that have their distribution and lateral extent controlled by the presence of extensional growth faults at the progradational listric fault fan. The boundary domain is a zone of larger salt walls that accumulated and rose partially due to the progradational loading of evaporites, which squeezed the evaporites to the west, to the central portion of the basin. The outer domain contains a series of thrusted and non-thrusted salt anticlines and salt pillows that have arisen as a result of regional north-south contraction in the eastern Mediterranean. -- Within the Cilicia Basin it is possible to delineate four major tectonic systems each system sharing a common purpose. They are: -- A) The Basin-Forming Tectonic System - those faults responsible for the formation of the basin -- B) Intra-Salt Gravitational Gliding Tectonic System - faults within the evaporite unit which record the change from a south tilted basin to a north tilting basin -- C) Convergent Fold and Thrust Belt Tectonic System - composed of the salt structures and faults which coincide with the hypothesized presence of a basin central extensional fault near the central part of the Cilicia Basin, which acts as a buttress to southward moving sediments -- D) Supra-Salt Gravitational Gliding Tectonic System - records extension related to delta progradation from the northeastern portion of the basin and the resultant contraction at the toe of the gravitationally controlled tectonic system -- The migration of evaporites in the Cilicia Basin is dynamically linked to the tectonic elements internal to the basin but are also strongly linked to large-scale regional tectonic activity of the Eastern Mediterranean.


identifier: Smith, Roderick L. <https://research.library.mun.ca/view/creator_az/Smith=3ARoderick_L=2E=3A=3A.html>   (2006) The basal gabbro subdivision and associated magmatic nickel-copper sulphide mineralization of the Pants Lake intrusion, Labrador, Canada : a combined geological, petrological, geochemical, and metallogenic study.  Masters thesis, Memorial University of Newfoundland.

abstract: The Pants Lake Intrusion (PLI), located in northern Labrador, represents an early phase of the 1.34 to 1.29 billion-year Nain Plutonic Suite that is located amongst the 1.45 to 1.46 billion-year old Harp Lake Intrusive Suite, the 1.85 billion-year Nain-Churchill Province suture zone, and the 2.78 to 1.74 billion-year Churchill Province which actually hosts the intrusion. The early evolution of the Pants Lake Intrusion is similar to that described for the Voisey's Bay Intrusion. -- The PLI is composed of two separate intrusions termed the North and South Pants Lake Intrusion. A U/Pb zircon and baddeleyite igneous crystallization age of 1322.2 ± 2 million years was derived from the north intrusion, whereas a U/Pb baddeleyite igneous crystallization age of 1337 +4/-2 million years was derived from the south intrusion. Apart from geographical proximity, and common origin and host, the north and south intrusions do not share many characteristics; in fact, the north intrusion intrudes the south intrusion. -- The South Pants Lake Intrusion, located in the southern part of the study area, is a weakly layered mafic body that intrudes the Harp Lake Intrusive Suite. The south intrusion is characterized by olivine cumulate-textured peridotite and troctolite compositions, high MgO abundances (up to 21 wt %), elevated light rare earth elements, positive Eu anomalies (Eu/Eu* = 1.19), and Ce/Yb ratios that resembles the range reported for the troctolites of the Voisey's Bay Intrusion (Ce/Yb = 26-31). -- Disseminated, blotchy, net, and les abundant massive textured sulphides are widespread in the south intrusion and are dominated by pyrrhotite with lesser chalcopyrite and pentlandite. Nickel tenors of the sulphide minerals are slightly elevated compared to those in the north intrusion due to the greater percentage of nickel available to partition into the localized sulphide liquid (as indicated by the elevated modal olivine). Sulphur isotopic ratios of sulphide mineral separates from the south intrusion range from -5.25 to -1.99 ‰, indicating the influence of the local sedimentary sulphide source. Partially digested gneissic inclusions are widespread and closely resemble inclusions present in the north intrusion, as well as inclusions described from the Voisey's Bay Intrusion. -- The North Pants Lake Intrusion is spatially much larger (up to 60 km²) than the south intrusion (10 to 15 km²). The north intrusion is a layered, horizontal to sub-horizontal, mafic sill-like body that is divided into the Upper and Basal Gabbro Subdivisions. These two subdivisions are present only in the north intrusion. Collectively the two subdivisions range from 100 to 400 meters thick, with the thickest parts present in the north part of the intrusion. The footwall contact of the intrusion is undulating and locally brecciated which aided the deposition of semi-massive to massive sulphide. Not much is known about the upper contact of the north intrusion, only that there was very little assimilation with the country rock gneiss. -- Unlike the south intrusion, the north intrusion pooled in a secondary magma chamber located in the upper crust prior to its final ascension and lateral emplacement. While in the secondary magma chamber, the magma fractionated, producing a plagioclase and olivine cumulate silicate liquid. With increasing assimilation of the surrounding sulphide-bearing Tasiuyak paragneiss, as indicated by sulphur isotopic ratios of -3.33 to -1.99 ‰, sulphide saturation and subsequent production of an immiscible sulphide liquid was induced within the silicate liquid. This was followed by partitioning of nickel from the silicate magma into the available immiscible sulphide liquid (< 650 ppm Ni in olivines of the north intrusion). The first pulses of fractionated silicate liquid to enter the sill chamber formed the Upper Gabbro, followed by the denser olivine-rich liquid that formed the Basal Gabbro. The point of entry for the silicate liquid feeding the Upper and Basal Gabbro as it entered the sill was near the northwest mapped boundary of the north intrusion. Magma injection into the northern part of the intrusion continued well after the main volume of Basal Gabbro had flowed into the sill. -- As the name implies, the Upper Gabbro forms the uppermost part of the north intrusion and is the more voluminous of the two subdivisions. Variations in the mineralogy and texture of the Upper Gabbro allow for the designation of four primary subunits. These are the Altered Gabbro, Coarse- to Medium-Grained Gabbro, Pegmatitic Gabbro, and Olivine Gabbro. These subunits constitute variations in a medium- to coarse-grained gabbro, containing cumulate plagioclase with intercumulate olivine and clinopyroxene, which are typically void of visible foreign contaminants and sulphides. Chemically, the Upper Gabbro is less varied than its basal counterpart. The Upper Gabbro has slightly elevated SiO₂, Na₂O, A1₂O₃, CaO, Rb, and Sr contents, but much lower FeO, MgO, Ni, Cu, and S concentrations compared to the Basal Gabbro. Rare earth element patterns exhibit slightly decreasing light to heavy rare earth element patterns and an average Europium anomaly of 1.24 which is comparable to the Basal Gabbro. -- The Basal Gabbro, present at the base of the North Pants Lake Intrusion, is approximately 27 meters thick and is distinguished primarily by the presence of partially digested gneissic inclusions coupled with the occurrence of magmatic-textured sulphides similar to the varied textured troctolites and basal breccia sequences described from the Voisey's Bay deposits. The Basal Gabbro is further subdivided into four primary subunits. These constitute the Transition Gabbro, Gabbro Hybrid, Olivine Gabbro, and Leopard Gabbro that collectively forms a recurring sequence present throughout the entire north intrusion. Overall, the major, trace, and rare earth element chemistry of the Basal Gabbro subunits mimics the chemistry of the Upper Gabbro, and where variations are present, they are most typically a direct consequence of gneissic and sulphide influences. -- Magmatic sulphide textures observed in the Basal Gabbro vary from disseminated, blotchy, leopard, to semi-massive and massive. The leopard texture, not present in the northern part of the intrusion, indicates areas of less turbulent flow. The largest massive sulphide intersections discovered to date is 15.7 meters of 1.13 % Ni, 0.78 % Cu and 0.20 % Co. Typical massive sulphide intersections are much smaller (< 1 meter) but have similar to slightly higher grades. Pyrrhotite is the most common sulphide present in the intrusion followed by chalcopyrite and pentlandite. Pentlandite is present as small (< 1 cm) inclusions and exsolutions within the pyrrhotite. Sulphides observed in the footwall are of two types, that is, sulphides remobilized from the main sulphide mass in the Basal Gabbro and unrelated sedimentary sulphides. One remobilized footwall sulphide intersection assayed 11.75 % Ni, 9.70 % Cu and 0.43 % Co over 1.1 meters. -- The North Pants Lake Intrusion is the closest analogue to intrusive rocks at the Voisey's Bay deposits recognized to date in Labrador. The present lack of identification of Voisey's Bay-like mineralization may be a function of observation level within the magmatic system. The northwestern margin of the intrusion offers the best exploration potential due to the recognition of new magma pulses, the potential feeder entry-point, and of course, spatial proximity to the most significant sulphide intersections encountered to date.


identifier: Winsor, Jonathan Dion <https://research.library.mun.ca/view/creator_az/Winsor=3AJonathan_Dion=3A=3A.html>   (2004) The Neogene development of the eastern Mediterranean Sea as manifested in and near the Rhodes Basin : an insight into arc-arc junctions.  Masters thesis, Memorial University of Newfoundland.

abstract: New multi-channel seismic data were acquired by Memorial University of Newfoundland (MUN) over the Rhodes Basin, eastern Mediterranean Sea, during the summer of 2001. Imaging challenges imposed by the deep water depth, short receiver array and channel and frequency specific noise were overcome by careful data processing. The final processed data generally yields good image quality for the first 1.5 seconds below the seabed with significant improvements in areas where the geology is simple and the Pliocene-Quaternary basin fill is thick. -- The Rhodes Basin is a deep (~4400 m) bathymetric trough located near the junction between the Hellenic and Cyprus Arcs. On the basis of this study, two major seismic-stratigraphic units are identified and described in detail: a pre-late Miocene unit (Eocene-Miocene) and a Pliocene-Quaternary unit separated by a laterally extensive unconformity, interpreted in this work as the M reflector. Hence, unlike most of the eastern Mediterranean, the Rhodes Basin has not preserved its Messinian stratigraphy (e.g., Messinian evaporites). This suggests that, since the late Miocene, it developed somewhat independently from the remainder of the eastern Mediterranean since the late Miocene. -- Analysis of structural and stratigraphic architectures reveals that the Rhodes Basin can be divided into three structural domains: a) Domain 1- the heavily sheared plateau, b) Domain 2- the folded and faulted deep Rhodes Basin and c) Domain 3- the Turkish continental slope. Structural and stratigraphic relationships within and between these structural Domains suggest that the Rhodes Basin has been subjected to two major episodes of deformation during the Neogene. The first deformation episode, P₁, is characterized by southeast-verging Miocene thrusting and uplift consistent with the emplacement of the Lycian Nappes to the northeast and fold/thrust complexes on the Island of Rhodes to the west. Following an early Pliocene period of regional subsidence associated with the opening of the Aegean Graben System, a middle Pliocene-Quaternary phase of northeast-southwest sinistral transpression (P₂) developed in response to an actively curving Hellenic Arc and the increasing obliquity of its eastern limb (Pliny-Strabo trench system) to the African Plate convergence vector. The middle Pliocene introduction of this strike slip deformation into the proto-Rhodes Basin re-activated the P₁ structural fabric as transpressional faults and facilitated rapid subsidence (~555-740 m/Ma) along its margins in a strike-slip pull-apart regime. The identification of a structural trend reminiscent of the Cyprus Arc and Hoyran-Beysehir Nappes along the eastern margin of the Rhodes Basin suggest that the Rhodes Basin marks the apex of the structurally complex Hellenic Arc/Cyprus Arc junction.


identifier: Wheaton, Chad J. <https://research.library.mun.ca/view/creator_az/Wheaton=3AChad_J=2E=3A=3A.html>   (2004) Tomographic traveltime inversion for linear inhomogeneity and elliptical anisotropy.  Masters thesis, Memorial University of Newfoundland.

abstract: A velocity model is described in which we assume that velocity increases linearly with depth and varies elliptically with propagation direction. That is, we consider a linearly inhomogeneous elliptically anisotropic model. The variation of velocity with depth is given in terms of parameters a and b, and the elliptical anisotropy is given in terms of parameter x. An analytical traveltime expression is then derived to account for the direct traveltime between an offset source and a receiver in a well; such as in a vertical seismic profile (VSP) setting. A method of inverting traveltime observations to estimate parameters a, b and x is derived. The application of this method is exemplified using a data set from the Western Canada Basin. The parameter estimation also includes a statistical analysis. In the above case, we obtain a good agreement between the field data and the model. Furthermore, the inclusion of elliptical anisotropy is validated by showing that an isotropic model is outside of the confidence interval for x. Once a, b and x are known, a further application is considered; namely, we use the model to calculate the possible reflection points, collectively referred to as the zone of illumination, for a VSP experiment with a given source-receiver geometry. Such modelling is useful for both data analysis and survey design. Two computer codes are given using Maple®. The first code is for the estimation of the parameters and the second one is for the calculation of the zone of illumination.


identifier: Bartholomew, Linda <https://research.library.mun.ca/view/creator_az/Bartholomew=3ALinda=3A=3A.html>   (1995) An investigation of L-moments and the generalized logistic distribution: applied as a new way to model ice strength.  Masters thesis, Memorial University of Newfoundland.

abstract: In cold ocean research the development of statistical techniques useful in the analysis of cold ocean data such as ice strength is of important practical concern. A central interest is the identification of and fitting of suitable models to the data, for the analysis of such data. In this practicum we study the theory of L-Moments as a method of distributional identification and parameter estimation. In particular, the Generalized Logistic Distribution (GLD) is fitted to nine data sets consisting of breaking strength measurements of different types of ice using the method of L-Moments. The results compare favorably to the original analysis of the data based on Maximum Likelihood fitting of the Weibull distribution. The asymptotic distribution of the L-Moment estimators is derived, and a test for the symmetry of the GLD, based on these asymptotic results, is developed. A Monte Carlo simulation study demonstrates the performance of the method of L-Moments for the estimation of the parameters of the GLD and compares it to the method Maximum Likelihood and the method of Moments. L-Moment estimators are easy to compute and perform consistently well across a wide range of parameter values. The method was found to be a simple and reliable method for estimation and distributional identification and thus it provides an attractive alternative method to the standard techniques. The application of this method to real data illustrates the implementation of the method and the contexts in which the method is useful.


identifier: Lorenz, Brenna Ellen <https://research.library.mun.ca/view/creator_az/Lorenz=3ABrenna_Ellen=3A=3A.html>   (1984) A study of the igneous intrusive rocks of the Dunnage Melange, Newfoundland.  Doctoral (PhD) thesis, Memorial University of Newfoundland.

abstract: The Dunnage Melange, located in the central mobile belt of the Appalachian Orogen, in north-central Newfoundland, is host to several suites of igneous intrusions. These include mafic through felsic dikes, stocks, and batholiths ranging in age from Early Ordovician through Jurassic. -- The tectonic environment and mode of origin of the Dunnage Melange, as well as the origin and significance of its intrusions, have long been a subject of controversy. The purpose of this study was to examine the field relationships between the intrusions and the host melange, and the geochemistry and petrography of the intrusions, in the context of this controversy. -- It was concluded that the melange and its intrusions were part of a complex and dynamic igneous, sedimentary and tectonic system, the local history of which was characterized by penecontemporaneous sedimentation, block faulting, olistostrome deposition, intrusion, and sediment slumping and sliding in Ordovician time. The earliest intrusions are mafic tholeiites with a chemistry indicative of a tensional environment, interpreted to be related to back-arc basinal rifting. The Dunnage Formation was then intruded, penecontemporaneously with sedimentation and melange formation, by a suite of silicic rocks (the Coaker Porphyry) that have a sedimentary source. These intrusions were followed closely in time by a calc-alkaline suite that was derived from an igneous or mantle source. On a regional scale, melange formation and intrusion of the Coaker Porphyry are interpreted to have taken place in a back-arc setting during the Early Ordovician subduction of the leading edge of the continental margin of North America, with partial melting of sediments from the continental margin giving rise to large quantities of silicic magma that permeated the overlying mantle wedge. Later calc-alkaline magmas were derived from the partial melting of this contaminated mantle.


identifier: Stouge, Svend <https://research.library.mun.ca/view/creator_az/Stouge=3ASvend=3A=3A.html>   (1980) Conodonts of the Table Head Formation (Middle Ordovician), western Newfoundland.  Masters thesis, Memorial University of Newfoundland.

abstract: On the Great Northern Peninsula, western Newfoundland, the transqressive Table Head Formation (Middle Ordovician) overlies the Lower Ordovician St. George Group. The Table Head strata are overlain by carbonate breccias and easterly derived flysch deposits. The Table Head sediments include limestones, mainly rubbly, with dolostones at the base (lower Table Head), overlain by limestones interbedded with shales (middle Table Head) and black graptolitiferous shales at the top (upper Table Head). The lower Table Head limestones represent the last platform carbonate deposit before the bank foundered probably due to the emplacement of Lower Ordovician allochthons in western Newfoundland. -- The formation has been studied in detail from eight localities in the area from Bellburns community in the south to St. John Island in the north. Additional information from localities on Port au Port Peninsula and Hare Bay is included. The Table Head sediments all along on the west coast of Newfoundland compare with those in the study area. The thickness of the different units varies considerably and reaches its maximum at Table Point. The detailed investigation of the rocks revealed that carbonate accumulation was interrupted by "catastrophic" downwarps of the shelf. These may be related to the emplacement of the allochthons. -- A total of approximately 17,000 conodonts was recorded within the study area. An additional 3,000 were recorded from elsewhere in western Newfoundland. The conodont fauna is described in multi-element taxonomy, and a supragenetic classification is applied. 35 genera and Panderodontidae, and the new recognized family Cornuodontidae n. fam.. -- Two phylo-zones and four biointerval-zones are defined. The phylo-zones are based on phylogenetically related and facies independent species of Histiodella. The species from the basal lower Table Head on Newfoundland belong to Midcontinent Fauna 4, and are correlative with strata from North America. The conodonts reinforce trilobite and cephalopod data that indicate a late Whiterockian (early Llanvirnian age for these strata. The North Atlantic Province conodonts from the middle Table Head have a number of species in common with the Eoplacognathus suecicus Zone of Scandinavia. The top of the middle Table Head at Table Point may be as young as the E. suecicus-P. sulcatus Subzone. -- The Table Head strata accumulated in lagoonal, shelf (inner-outer) and slope environments. The lateral distribution of conodonts can be directly related to these depositional environments, and a sequence of three biofacies and sub-biofacies is introduced. The lagoonal (Midcontinent Province) and slope (North Atlantic Province) biofacies are distinct, whereas the shelf biofacies is less distinct. The occurrence of occasional invaders from the open oceanic biofacies can be related to the oscillating transgression.


identifier: Churchill, Rodney A. <https://research.library.mun.ca/view/creator_az/Churchill=3ARodney_A=2E=3A=3A.html>   (1994) An integrated study of epigenetic gold mineralization, Duder Lake Area, Northeastern Newfoundland.  Masters thesis, Memorial University of Newfoundland.

abstract: The Duder Lake area is located within the eastern Dunnage Zone of the Newfoundland Appalachians, being part of the volcano-sedimentary Exploits Subzone. The study area is underlain by a mixed succession of late Ordovician to middle Silurian sedimentary and volcanic rocks which are intruded by numerous small gabbroic dykes and sills of Silurian to Devonian age. These sills and dykes were emplaced late in the deformational history of the area, but exhibit features suggesting that emplacement coincided with movement along a major fault system termed the Dog Bay Line. All units preserve three phases of deformation as well as a low- to mid-greenschist facies metamorphic mineral assemblage. -- Recent exploration activity in this area, and elsewhere in the eastern Dunnage Zone, has indicated that the gabbros and graphitic sedimentary rocks host gold-bearing pyrite and arsenopyrite mineralization. The sulphide mineralization in most instances is structurally controlled following low angle Riedel shears which appear to be late structures related to the Dog Bay Line fault system. Fluid/rock and CO₂/H₂O ratios, as determined from alteration mineral assemblages, diminish away from the mineralized shear zones producing a distinctive alteration zonation that is characterized by sulphidation, carbonatization and silicification. The hydrothermal alteration overprints the regional metamorphic assemblages. -- Detailed geochemical, isotopic and microthermometric studies suggest that the fluids responsible for the auriferous mineralization were derived from metamorphic devolatilization reactions in both Gander Zone basement rocks and the overlying allochthonous cover rocks of the Dunnage Zone during a Silurian orogenic event. The fluids, having sampled lithologically complex and diverse country rocks, were enriched in CO₂, H₂O, Au, As and Sb and were focused into large, late structures transecting the crust. -- Geochemical data suggest that the Au was transported as bisulphide complexes that were destabilized due to changes in redox conditions in the carrier fluid from reducing to relatively more oxidizing. The physico-chemical controls acting at the time of mineralization were such that Au precipitated simultaneously with As and S, resulting in its incorporation within arsenopyrite. As a result, gold at the Duder Lake occurrences is not free and is best described as invisible. -- Similarities between the Duder Lake gold occurrences and others elsewhere in the Dunnage Zone with similar ages and geological relationships suggest that the processes inherent in the formation of the Duder Lake occurrences may have been of a regional extent. As such the Duder Lake genetic model may be applicable to these other occurrences as well.


identifier: Blais, Estelle <https://research.library.mun.ca/view/creator_az/Blais=3AEstelle=3A=3A.html>   (1992) Deep crustal seismic reflection profiles across the Little Carpathians and adjacent margins of Vienna Basin and West Danube Basin in Czechoslovakia.  Masters thesis, Memorial University of Newfoundland.

abstract: Within the accretionary wedge forming the Carpathians of Central Europe, several 'basement' horsts occur within the usual sequence of thrust wedges, or nappes. This thesis is concerned with one such anomaly - the Little Carpathian horst in the Western Carpathians in Czechoslovakia. The horst is located between two deep post-nappe basins: the Vienna and West Danube basins, so that the structural relations with the underlying nappe sequences is unclear from surface geology. -- The main objective of this study is to define the structure of the Little Carpathian portion of the accretionary prism and the basin margins. To address this tectonic problem, three seismic reflection lines from Geofyzika Brno were reprocessed. The objective of the reprocessing was to improve the signal-to-noise ratio and velocity analysis to enhance reflectors buried in cultural noise (12.5 Hz and 16.7 Hz) in many places. Deconvolution, bandpass filtering, frequency filtering and velocity analysis were the main steps of reprocessing. Only common-mid-point (CMP) gathers without binning information were available, thereby limiting re-processing to post gather processes. Reprocessing greatly attenuated diffractions at the margins of the Vienna basin and West Danube basin and improved signal-to-noise ratio in some zones of the seismic sections. The main objectives of reprocessing were met though the extent of improvement is modest. -- The interpretation of the reprocessed seismic sections yielded interesting results. Late Cretaceous thrust related structures within the Little Carpathian horst were identified, such as the base of the Bratislava massif, thrust onto the Modra massif. A trailing imbricate fan structure within the Envelope nappe was also imaged. Reflections at the margin of the Vienna basin and West Danube basin were correlated with borehole data, and their dips are in agreement with no or very little thermal subsidence in the Vienna basin as the reflections are close to horizontal and faulting is intensive.


identifier: Briggins, David Rodney <https://research.library.mun.ca/view/creator_az/Briggins=3ADavid_Rodney=3A=3A.html>   (1992) Characterization of fracture roughness and its role in modelling the stress-flow behaviour of fractured rock.  Masters thesis, Memorial University of Newfoundland.

abstract: The importance of fracture roughness in the mechanical and hydraulic behaviour of fractured rock has long been recognized but quantitative modelling of its effects has proven to be difficult. This study addresses the characterization of fracture roughness and assesses some of the existing stress-flow models that exist in the literature. As part of the study, laboratory stress-flow tests were carried out on a single, natural fracture in a 20 cm diameter granite core. These were followed by injection of an epoxy resin into the fracture plane at a specified normal stress and flow rate. The resin injection experiment enabled direct measurements and characterization of the roughness of both sides of the fracture, contact area, aperture and void space. Statistical analysis of these parameters indicated that the distributions were skewed towards zero and could be approximated reasonably well by a log-normal distribution. All of the stress-flow models examined, including the parallel plate model, were found to have limited application or required simplifying assumptions with respect to fracture roughness. From the results of this study it is clear that fracture flow theory must take into account both sides of the fracture, the variation and spatial distribution of fracture aperture, and the different scales of roughness that exist.


identifier: Brace, Terry D. <https://research.library.mun.ca/view/creator_az/Brace=3ATerry_D=2E=3A=3A.html>   (1990) Geology, geochemistry and metallogeny of the Archean Florence Lake Group and associated ultramafic and trondhjemitic rocks, Nain Province, Labrador.  Masters thesis, Memorial University of Newfoundland.

abstract: The Florence Lake Group (FLG) forms a 65 km-long northeast-trending greenstone belt within the southernmost Archean Nain Province, Labrador. The FLG contains a bimodal volcanic sequence consisting dominantly of mafic metavolcanic schists, flows and pillow lavas, and minor synvolcanic sills. Felsic metavolcanic and siliceous metasedimentary rocks are less extensive. The FLG is intruded by elongate bodies of strongly serpentinized peridotite, which have undergone various degrees of carbonatization. Massive, gneissic and mylonitic trondhjemite and tonalite of the Kanairiktok Intrusive Suite envelop and intrude both the FLG and the metaperidotites. All units are folded and have undergone middle greenschist facies metamorphism. Post-tectonic Proterozoic diabase and gabbro dykes, informally referred to as the Florence Lake (FL) dykes, cut all other lithologies. -- Based on the relative depletion of LREE, FLG basalts can be divided into two groups: (1) Group 1 has flat chondrite-normalized REE patterns; (2) Group 2 is slightly LREE-depleted. The FLG basalts are similar to typical N-MORB, whereas the felsic supracrustal rocks and Kanairiktok trondhjemites display classic arc (or continental crust) signatures. Both lithological and geochemical characteristics are consistent with the FLG having been deposited subaqueously in a back-arc basin which lay proximal to a volcanic arc and/or continental margin. -- The Proterozoic FL diabase and gabbro dykes appear to be of two ages: (1) an older set of north- to northeasterly-trending gabbro dykes, viz., the FL gabbro dykes; and (2) an apparently younger set of east-west-trending smaller diabase dykes, viz., the FL diabase dykes. The FL gabbro dykes may be equivalent to the Harp dykes further to the north; however, the FL diabase dykes are chemically more evolved than other Proterozoic mafic suites in Labrador, with the exception of the Nain HP (high P₂O₅) dykes, with which they are very similar. -- The metaperidotites which intrude the FLG are enriched in Mg, Ni and Cr, and appear to consist dominantly of serpentinized dunites. Fe-Ni-Cu (+ minor PGE) sulphides hosted by meta-ultramafic rocks at the Baikie showings are interpreted to be magmatic in origin, and concentrations of PGE, Ni and Cu indicate that the metaperidotites south of Florence Lake and the meta-ultramafic xenoliths at the Baikie showing are komatiitic. -- Magnesite-quartz rocks southeast of Florence Lake are chemically similar to the metaperidotites. The alteration is somewhat similar to that associated with Archean lode gold deposits. However, abundant quartz veins which infill tension gashes in the rocks appear to have formed in situ due to the carbonatization process, and shear-related silicification and/or sulphldation is absent. -- Although metavolcanic and metasedimentary rocks of the FLG host many thin syngenetic pyrite horizons and several small base-metal sulphide occurrences, no significant mineralization has been discovered.


identifier: Bijaksana, Satria <https://research.library.mun.ca/view/creator_az/Bijaksana=3ASatria=3A=3A.html>   (1991) Magnetic anisotropy of Cretaceous deep sea sedimentary rocks from the Pacific plate.  Masters thesis, Memorial University of Newfoundland.

abstract: Palaeomagnetism and magnetic anisotropy are measured for Cretaceous deep sea sedimentary rocks cored from the Pacific plate by the Deep Sea Drilling Project. The objective is to use magnetic anisotropy to test whether sediment compaction during burial is responsible for the shallowing of remanence inclination reported previously for these rocks. -- The present palaeomagnetic study confirms that except at site 463 remanence inclination is shallower than expected. Careful alternating field demagnetization shows that the inclination shallowing is not likely due to a shallow overprint. -- Anisotropy of anhysteretic susceptibility (AAS) measurements reported in this thesis show that most specimens (except those from site 463) have a high degree of magnetic anisotropy (averaging 15%) with strong foliation in the bedding plane as would be expected from sediment compaction. Correlation found between degree of magnetic anisotropy and density for both claystones and limestones suggests that the anisotropy was enhanced by compaction. For the claystone specimens, the hypothesis of sediment compaction causing inclination shallowing is supported by a correlation found between the inclination shallowing and the AAS degree of anisotropy. No such correlation is found for the limestones perhaps because they magnetized earlier in the compaction process. The claystone results suggest that at mid-palaeolatitudes claystones with AAS degree of anisotropy of about 15% may show a compaction-induced inclination error of 5° leading to an underestimation of palaeolatitude of 4°. -- Both claystones and limestones seem to show an inclination shallowing of about 12°, which is independent of anisotropy and thus is probably not compaction-induced. Perhaps inaccuracies in the apparent polar wander path for the Pacific plate are responsible. -- The axis of minimum anhysteretic susceptibility deviates an average of only 5° (± 3°) from vertical orientation in the DSDP specimens with about 15% anisotropy. Perhaps AAS could be used to locate the bedding plane in massive sediments. -- The magnetic susceptibility of most specimens was too weak for its anisotropy to be reliably measured. However, the susceptibility anisotropy of the stronger specimens did resemble the AAS but was weaker. -- Key words: palaeomagnetism; Pacific plate; Cretaceous; deep-sea sedimentary rocks; remanence inclination shallowing; magnetic anisotropy; sediment compaction.


identifier: Thurlow, J. Geoffrey <https://research.library.mun.ca/view/creator_az/Thurlow=3AJ=2E_Geoffrey=3A=3A.html>   (1981) Geology, ore deposits and applied rock geochemistry of the Buchans Group.  Doctoral (PhD) thesis, Memorial University of Newfoundland.

abstract:
The Buchans Group is a regionally extensive, submarine, calc-alkaline volcanic suite erupted at a point in time near the Ordovician-Silurian boundary. It is subdivided into Lower and Upper Subgroups, each of which consists of interbedded mafic to felsic flows, breccias, pyroclastics and related sediments. The Lower Subgroup, which contains the economic ores, consists of four volcanic formations which have been repeated structurally by thrust faults, forming seven major volcanic sequences. The economically barren Upper Subgroup is subdivided into three major sequences. -- Plutonic rocks associated with the Buchans Group include the Feeder Granodiorite, Hungry Mountain Complex and the Topsails Granite. The earliest of these, the Feeder Granodiorite, is considered to be a time-equivalent plutonic facies of the Buchans Group. Deformed plutonic facies of the Hungry Mountain Complex were tectonically emplaced upon the Buchans Group during a major episode of southeast-directed Silurian thrusting. The Siluro-Devonian Topsails Granite intrudes all older formations and, in the Buchans area, consists of two main phases: a high level alkali-feldspar phase and a coarser grained equigranular peralkaline phase. Gently dipping alkali amphibole-bearing ignimbrite forms roof pendants within the Topsails Granite. These are interpreted as extrusive equivalents of the Granite and may be outliers of the Springdale Group -- The Buchans ores are high grade polymetallic massive sulphide deposits associated with submarine felsic volcanic rocks near the top of the Lower Buchans Subgroup. Three genetically related ore types are recognized; stock-work ore, in situ ore, and mechanically transported ore. Stockwork ore consists of networks of veinlet and disseminated base metal sulphides within highly silicified and locally chloritized host rocks. In situ ore lies stratigraphically above stockwork mineralization and is composed of banded to streaky yellow ore, black ore and barite. Transported ore consists of discrete sulphide and barite fragments in breccias which flank in situ ores and form substantial distinct orebodies. Their origin is interpreted as a result of brecciation at source, transport down-slope in paleotopographic channels by gravity-driven submarine debris flows, and deposition in depressions. The Buchans ores and their environment are similar to those of the Japanese Kuroko deposits in almost all respects. -- Whole-rock chemical analyses have shown that Buchans Group volcanic rocks are similar in chemical abundances and variations to other calc-alkaline volcanic suites. There was apparently little chemical evolution in Buchans Group flows through the stratigraphic column, and
flows within the ore horizon sequences are essentially similar to their counterparts elsewhere in the Buchans Group. Pyroclastic rocks of the ore horizon are chemically similar to those at other stratigraphic horizons and show no anomaly related to mineralization with the exception of high Ba content. -- Study of the unaltered pyroclastic rocks of the ore horizon has shown that there are no regional variations in element concentrations, element ratios, discriminant scores or factor scores, either along or across stratigraphy, which bear relationship to mineralization. Erratic base metal concentrations are present in host pyroclastic rocks only within 50 m of ore. Visibly altered footwall rocks have undergone chemical changes typical of rocks in most massive sulphide terranes. -- Anomalously high concentrations of Ba in ore horizon pyroclastics is a regional feature which provides a means of distinguishing ore horizon pyroclastics from similar lithologies at other stratigraphic horizons. The Ba anomaly is caused by microscopic barite which was widely distributed by subaqueous pyroclastic flows which transported most ore horizon pyroclastics.


identifier: Le, Van Minh <https://research.library.mun.ca/view/creator_az/Le=3AVan_Minh=3A=3A.html>   (1994) Geochemical and palynological characteristics of tertiary oil shales and lignites of the Mae Moh Basin, northern Thailand.  Masters thesis, Memorial University of Newfoundland.

abstract: The sources of organic matter, the depositional conditions during lacustrine/swamp phases, the degree of post-depositional thermal alteration are examined for a Tertiary intermontane basin in northern Thailand, the Mae Moh Basin. Alternating oil shale and lignite layers in this basin also preserve a record of changing temperature and precipitation patterns, and variable contributions from swamp flora and lake primary producers. -- Variations in molecular and isotopic geochemical characteristics (including compound-specific stable carbon isotope compositions) and spore and pollen assemblages (including thermal alteration index) across a 300 meter section of the Middle Mae Moh Formation are investigated. Samples collected are classified into: group I, lignite; group II, argillaceous lignite; and group III, oil shale. The saturate fraction for all samples is dominated by n-alkanes from C₁₅ to C₃₃. Group I is characterized by a high abundance of the high molecular weight (HMW) C₂₆ to C₃₃ (up to 82%), and a low abundance of the low molecular (LMW) C₁₅ to C₁₉ (3 to 8%). Group III has a lower abundance of the HMW alkanes (29 to 66 %), and a greater abundance of the LMW homologues (13 to 43 %). Group II has n-alkane distribution that is intermediate between these end members. Although the dominance of higher plant contributions is indicated throughout the section, the oil shales clearly received substantial contributions from lake primary producers (algae). These molecular trends are consistent with the δ¹³C values determined on bulk samples, which vary from -22.5 to -26.8‰. The δ¹³C of n-alkanes in the HMW range, which are mostly lighter than -30‰, also substantiate a dominantly higher plant source. Algal contributions are suggested by the relative abundance of LMW alkanes with carbon isotopic compositions (about -24 to -30 ‰), which are somewhat enriched compared to the HMW homologues (-28 to -35‰). -- Decomposition and settling conditions of organic particulates are inferred from the pristane/phytane ratios (Pr/Ph). Oil shale samples, having Pr/Ph ratios close to unity (0.95 to 1.58), were likely deposited during oxic-anoxic fluctuations on the bottom of lakes and bogs within the basin. Deposition and degradation of lignitic organic matter probably occurred in prevailing oxic conditions as indicated by their Pr/Ph values that range from 1 to 3.53. -- The degree of thermal maturation given by thermal alteration index (TAI) values ranging from 2.0 to 2.4 and carbon preference index (CPI) from 0.63 to 3.77 (most values are > I) indicate immature to early mature stages in terms of oil generation for Mae Moh source rocks. The spore and pollen assemblages are mainly palm (Spinizonocolpites, Oncosperma, Calamuspollenites, and Cyrtostachys), fern (Verrucatosporites sp. and Polypodiidites sp.), deciduous trees (Quercoidites, Alnipollenites, and Trivestibulopollenites), and other specimens of unknown affinity: Crassoretitriletes sp., Trichanthera sp., Monosulcites, CupuUferoipollenites, Biretisporites huonensis and Roipites sp.. Their temporal variations suggest a dominant tropical paleoclimate with possible cooler conditions in the early stage of basin evolution.


identifier: Schaefer, Richard Alan <https://research.library.mun.ca/view/creator_az/Schaefer=3ARichard_Alan=3A=3A.html>   (1994) Effects of fracture geometry on fluid flow through the Monterey Formation, California : an application of a 3D discrete fracture simulator.  Masters thesis, Memorial University of Newfoundland.

abstract: Outcrops of the fractured and folded sedimentary Monterey Formation located along or near the coast of central California were sampled to characterize the geometry of the fracture system and determine the impact of the fracture geometry on rock mass permeability. A scanline mapping technique was used to obtain: orientation, trace length, spacing, mineral infill, termination, censoring, and shape data for over 1700 individual discontinuities. Analyzing the general fracture characteristics, using cluster analysis of the poles to fracture planes, and taking into account the different structural settings, it was determined that there were two to three fracture sets at each of six different locations. Four of these locations, were part of a "small-scale" fracture survey where short scanlines (≤ 30 m) sampled fractures 0.25 m or greater in trace length from individual outcrops. The other two locations, were a composite of sites sampled for "large-scale" fractures (extensive breccias and faults) with trace lengths greater than 3 m, using long (100 m to 1400 m) scanlines. The strike of the dominant fracture set at most small-scale sites was sub-parallel to bedding dip direction. Generally the fractures in the subordinate set had shorter trace lengths that terminated against and were approximately perpendicular to the fractures making up the dominant set. The two large-scale sites had three sets, one sub-horizontal, one sub-parallel to bedding strike, and the other sub-parallel to bedding dip direction, all with similar mean lengths. -- Statistical methods were used to correct for some of the biases, associated with scanline mapping, in the trace length, spacing and orientation data. Straight lines, drawn through the data points on probability plots show that die fracture trace length and spacing data can be approximated by a lognormal distribution. The statistics of trace length, density, and orientation obtained from the field data, along with assumed aperture distributions were used in a 3-D discrete fracture flow simulator to evaluate the impact of the variability in fracture orientation, fracture interconnectivity, and aperture on rock mass permeability. Simulations of rock mass cubes with side length of 8 to 18 meters for the small-scale data and 100 to 150 meters for the large-scale data, found that the fracture geometry was well connected and imparted a strong anisotropy to flow in the horizontal section and less so in the vertical section, when the same aperture was assigned to each fracture. When the apertures for individual fractures were generated using a lognormal distribution the computed directional permeabilities became even more anisotropic to flow.


identifier: Moore, Paul J. <https://research.library.mun.ca/view/creator_az/Moore=3APaul_J=2E=3A=3A.html>   (1991) Geology and geochemistry of mafic rocks from ophiolites of East Nelson, New Zealand.  Masters thesis, Memorial University of Newfoundland.

abstract: In the East Nelson area, ophiolitic rocks of the Dun Mountain Ophiolite Belt (East Nelson ophiolites) have been described by past workers as representing either a single disrupted ophiolite suite or a number of distinct ophiolite suites. -- Through geochemical evaluation of mafic rocks of the East Nelson ophiolites, it has been determined that potentially three separate ophiolite suites exist; the Dun Mountain Ophiolite, the Patuki mélange and the Croisilles mélange. -- The Dun Mountain Ophiolite represents a semi-complete ophiolite suite. Geochemical evidence indicates that mafic rocks of this ophiolite are of island-arc tholeiite composition and have been produced by partial melting of depleted mantle above a subduction zone. The disrupted and relatively incomplete nature of the ophiolite is considered to be the result of tectonic activity associated with obduction and later orogenesis. -- Unconformably overlying the Dun Mountain Ophiolite are local accumulations of conglomeratic material, known as the Upukerora Formation. Clasts within this formation closely resemble lithologies observed within the Dun Mountain Ophiolite and pyroxenes analyzed from clasts are found to be compositionally similar to those observed within the ophiolite. -- Rocks of the Patuki and Croisilles mélanges lie in fault contact with, and underlie the Dun Mountain Ophiolite. Blocks within the mélanges consist of sedimentary, mafic to ultramafic volcanic and plutonic rocks suspended in matrices dominated by sheared serpentinite. Although these rocks are highly disrupted, they are considered to represent vestiges of true ophiolitic assemblages, as representative lithologies of an ophiolite are observed within the blocks. These rocks likely represent fragments of oceanic crust subducted beneath the Dun Mountain Ophiolite. -- Basaltic rocks of the Fatuki and Croisilles mélanges are divided into two petrographically and geochemically defined suites; a mid-ocean ridge suite and an alkaline within-plate suite. Geochemical evidence suggests mid-ocean ridge basalts of the mélanges are indistinguishable and therefore it is suggested that the mélanges may represent dislocated portions of the same oceanic basement. -- A fore-arc environment of formation is favoured for the origin of the Dun Mountain Ophiolite. By this model the Patuki and Croisilles mélanges are considered fragments of normal ocean crusts sheared off the subducted slab during subduction.


identifier: Sabetu, Obet <https://research.library.mun.ca/view/creator_az/Sabetu=3AObet=3A=3A.html>   (1993) Rainfall distribution in West Timor: temporal and spatial characteristics, regional frequency analysis and drought identification.  Masters thesis, Memorial University of Newfoundland.

abstract: This study of rainfall distribution in West Timor is concerned with the analysis of temporal and spatial rainfall characteristics, regional frequency analysis of annual daily maximum rainfall and pentad (5-days) drought analysis. Several statistical properties such as persistency, trend and seasonality of rainfall series, and also physical factors such as topography and prevailing winds are used to describe the general characteristics of rainfall. The index-rainfall and L-moment approaches are used to provide a regional probabilistic model of annual daily maximum rainfall and, for comparison, the at-site frequency of selected gauges is analyzed. Probability analysis is used to describe pentad drought properties such as onset and end of the rainy season, severity, and vulnerability of drought. -- The results of this study show that the rainfall characteristics in West Timor are variable in time and space. The prevailing wind system and topography are the dominant physical factors affecting the spatial and temporal distribution of rainfall in this region. West Timor can be classified into one homogenous rainfall region based on annual daily maximum rainfall analysis, but into two homogenous rainfall regions based on monthly rainfall analysis. The Gumbel distribution is an acceptable model for at-site and regional frequency analysis. -- The severity and vulnerability of drought is significant even in the wet season. At site 6 for example, only two months in the wet season are wet enough for rice, and only four months for dry land crops at a reliability level of 75%. The results of this study should provide better guidance to engineers involved in irrigation and agricultural planning in West Timor. In addition, the results obtained provide an up date of an earlier study by Crippen Consultants (1980).


identifier: Cumming, Ewan Hugh <https://research.library.mun.ca/view/creator_az/Cumming=3AEwan_Hugh=3A=3A.html>   (1990) Seismic stratigraphy and late Quaternary sedimentary history of Bonavista Bay, northeastern Newfoundland.  Masters thesis, Memorial University of Newfoundland.

abstract: The Late Quaternary glacial and sedimentary history of Bonavista Bay, on the NE coast of Newfoundland, is interpreted from 545 line km of high-resolution seismic reflection data and three piston cores. Seismic data from the open, outer region of Bonavista Bay display three seismic units (1-3) overlying acoustic basement within two broad, shallow basins. The surveyed inner region of Bonavista Bay contains narrow, deep basins which commonly host four seismic units (A-D) above acoustic basement. -- Glacial sediments are represented by seismic units 1 and A, both of which are acoustically incoherent. Unit 1 is generally <15 ms thick and has a variable morphology. It is correlated with a stiff, sandy, gravelly mud (diamicton). Unit A is up to 110 ms thick and ponded. Units 2, B and C are proglacial sequences. Unit 2 is acoustically stratified, <20 ms thick and has a draping basin-fill morphology. It is correlated with an interlaminated sequence of distal turbidites and hemipelagic/ice-rafted sediment. Unit B is acoustically transparent, ponded and up to 30 ms thick. It corresponds with a proglacial homogeneous silty mud, rapidly deposited under open water conditions until 12,790 y BP (in Chandler Reach). Unit C, overlying B, is acoustically stratified, up to 90 ms thick and has a draping basin-fill morphology. It is correlated with a sandy, pebbly and shelly mud, deposited by hemipelagic, terrestrial and ice-rafted sedimentation from 12,790 y BP to 10,170 y BP. Seismic units 3 and D are acoustically transparent post-glacial sequences with an average thickness of 20 ms. They display a draping basin-fill morphology which has been altered by erosion and are correlated with a sandy, pebbly and shelly hemipelagic mud; initially deposited in the outer bay by 13,500 y BP and in the inner bay by 10,170 y BP (Chandler Reach). -- Bonavista Bay was host to a grounded Late Wisconsinan ice sheet. Deglaciation of the bay was rapid and occurred at a time of rising sea level. Initially a thin basal till was deposited beneath grounded ice. With lift-off, an ice shelf formed over the basins of the outer bay. Retreat of the grounding line paused briefly on the basin margins, where discontinuous moraines were deposited. The ice sheet also became buoyant within the northeasternmost basin of the inner bay during this period. Diamictons (seismic units 1 and A) were subaqueously deposited within basins beneath the floating ice. Following ablation of the ice shelf, ice margins persisted near the SW and western regions of the outer bay, providing sediment for proglacial turbidity currents within the basins (unit 2). Geostrophic currents largely limited deposition of hemipelagic sediments to within the basins of the outer bay. -- The basins of the inner bay were gradually deglaciated while unit 2 was deposited. Fine-grained outwash sediment (unit B), transported by interflows, was rapidly deposited as the ice margin retreated to a terrestrial position by at least 12,790 y BP. The region of the inner bay remained under the influence of one or more ice margins until 10,170 y BP, with ice at the position of an inland end moraine and probably on the Bonavista and Gander Peninsulas. Normal marine conditions were present in the outer bay by 13,500 y BP and throughout the entire region by 10,170 y BP. The Labrador Current has eroded Holocene and perhaps Wisconsinan sediments. -- The deglacial sequence of events within Bonavista Bay and the sediments present, suggest that ice was channelized in the bay during the Late Wisconsinan, either at glacial maximum or during a deglacial surge which was driven by a collapsing ice cap from the SW.


identifier: Weick, Reinhold James <https://research.library.mun.ca/view/creator_az/Weick=3AReinhold_James=3A=3A.html>   (1993) Petrography and stable isotope geochemistry of alteration and mineralization in the Rambler volcanogenic massive sulphide deposit, Baie Verte, Newfoundland.  Masters thesis, Memorial University of Newfoundland.

abstract: The Rambler is one of the five VMS deposits of the Consolidated Rambler Mines properties which occur in the Pacquet Harbour Group; a deformed and metamorphosed sequence of volcanic and sedimentary rocks located on the east half of the Baie Verte Peninsula in Central Newfoundland. The deposit contains alteration and base metal sulphide assemblages typically associated with VMS mineralization, but is highly deformed and occurs as a northeast trending, shallow dipping, ellipsoidal body, above a prominent imbricate shear zone. The syn-kinematic quartz + muscovite ± chlorite assemblages in the shear zone are of uncertain origin, but similar to the alteration in several epigenetic / mesothermal gold prospects which occur throughout the Baie Vert region. The alteration and sulphide assemblages associated with the deposit and its shear zone are cut by quartz-carbonate veins which contain their own characteristic alteration assemblages. All alteration assemblages are overprinted by disseminated biotite related to a late metamorphic event. -- Oxygen isotope thermometry and calculated δ¹⁸O and δD fluid values confirm a complex thermal and fluid history in the Rambler deposit. An early high temperature event is recorded by the isotopic composition of a dark green variety of chlorite in massive sulphide horizons, which equilibrated with a high ¹⁸O magmatic fluid; δ¹⁸O and δD values of +9.0 to +9.4‰ and -39‰ at 430 to 480°C. A decrease in temperature (-200 to 300°C) and shift in δ¹⁸O and δD fluid values to +4.4 and +4.6‰, and -26 to -37‰, respectively, are associated with the occurrence of a pervasive secondary light green chlorite which may have equilibrated with a mixture of seawater and metamorphic fluids during greenschist metamorphism and deformation of the Pacquet Harbour Group. The presence of an additional low ¹⁸O (< +5‰) low D (<-60‰) fluid during deformation is suggested by δ¹⁸O and δD mineral values of +6.4 to +8.2‰ and -55 to -70‰ for muscovite which are out of equilibrium with values of +2.9 to +7.5‰ and -57 to -73‰ for coexisting chlorite. Low δ¹⁸O chlorite fluid values of 0 to +4.1 ‰ at 180 to 200°C may be related to an influx of meteoric waters during the formation of quartz-carbonate veins. -- Metamorphic biotite in the stratigraphy of the deposit appears to have equilibrated with a high ¹⁸O fluid, with δ¹⁸O values as high as +7.5 ‰ and δD values of -41 to -49‰ at temperatures of 540 and 560°C. Similar biotite occurs in contact metamorphic assemblages along the margin of the Burlington Granodiorite to the west of the Consolidated Rambler Mines properties. -- Alteration mineralogy and isotopic composition of the low ¹⁸O-low D fluid which affected the Rambler is distinct from the isotopic composition of the CO₂-rich, low D fluids in equilibrium with chlorite and muscovite during the formation of two epigenetic / mesothermal gold deposits in the Baie Verte and Springdale regions. The replacement of seafloor assemblages in massive sulphide horizons by syn-kinematic assemblages in the footwall shear zone suggests the distinct low ¹⁸O-low D hydrothermal fluid may have evolved from the influx and mixing of formational and meteoric fluids during the obduction and imbrication of the Pacquet Harbour Group and its emplacement over the Laurentian continental margin.


identifier: Dunsworth, Sherry Mary <https://research.library.mun.ca/view/creator_az/Dunsworth=3ASherry_Mary=3A=3A.html>   (1989) Multiple intrusion and deformation within the northwestern quadrant of the plutonic complex, Troodos Ophiolite, Cyprus.  Masters thesis, Memorial University of Newfoundland.

abstract: Detailed geological mapping (1:5,000) of a 16 sq. km. area was completed within the northwestern quadrant of the Troodos plutonic complex, Cyprus. The plutonic complex incorporates an older, high-temperature deformed sequence of harzburgite, dunite, transition zone orthopyroxenite and layered olivine and hypersthene gabbro that is intruded and truncated/disrupted by a series of post-kinematic ultramafic-mafic (i.e.: wehrlite, feldspathic-wehrlite, lherzolite, feldspathic-lherzolite, clinopyroxenite, websterite and pyroxene-hornblende gabbro) plutons. Post-kinematic mafic dikes intrude both the older and younger magmatic suites, marking the final stage of magmatism within this section of the ophiolite. -- A penetrative, steep to subvertical regional S₁ foliation, traced intermittently from the harzburgite tectonite into portions of the layered olivine gabbro tectonite, is coaxial to large scale infolding of the dunite-harzburgite boundary. An equant granoblastic to porphyroclastic microfabric prevails in the harzburgite, dunite and transition zone lithologies whereas the layered gabbro exhibits both primary cumulate igneous and secondary ductile deformation textures. The structurally highest position of the high-temperature ductile deformation, termed the deformation front and marked by the transition from ductile to brittle deformation mechanisms, occurs within the layered olivine gabbro of the Troodos plutonic complex. -- The plutons of the younger suite represent variable sized, spatially and temporally distinct, fault-controlled magma chambers that are focused primarily along the transition zone of the older suite. Most of the older suite transition zone orthopyroxenite and part of both the dunite and layered gabbro have been removed through faulting and intrusion of the younger suite plutons. -- The fractional crystallization sequence of the older suite layered gabbro and the younger suite ultramafic-mafic lithologies is olivine -> clinopyroxene -> orthopyroxcne -> plagioclase -> +/- hornblende (+/- quartz). Textural features indicate simultaneous crystallization of the pyroxene phases within the gabbroic units. Electron microprobe studies indicate that the younger and older suites cannot be distinguished on the basis of their respective mineral chemistry, that fractionation trends occur within both the younger and older suites and that cryptic chemical layering cannot be detected over a 20 m section of the layered olivine gabbro. The mafic dikes exhibit a tholeiitic affinity (island-arc tholeiite) and an extremely depleted, Mg-rich and Ti-poor chemistry correlative with the depleted upper pillow lava suite and indicative of derivation from a residual mantle source that had undergone previous partial melting and melt extraction event(s). -- A dynamic crustal accretionary history consisting of multiple intrusion and ductile-brittle deformation is established for the Troodos plutonic complex. The geometrical relations between the penetrative regional foliation, infolding along the paleo-Moho and orientation of the enveloping surface of this folded dunite-harzburgite boundary at a high-angle to the regional foliation suggest that the Troodos ophiolite may represent a segment of diapirically flowing asthenosphere in an ancient ocean spreading region.


identifier: Richter, Susan <https://research.library.mun.ca/view/creator_az/Richter=3ASusan=3A=3A.html>   (1994) Relationships of flow and basin variables on the island of Newfoundland, Canada with a regional application.  Masters thesis, Memorial University of Newfoundland.

abstract: A hydrological study of the island of Newfoundland (Canada) was carried out to identify the key basin characteristics associated with a range of flow measures and to assess the potential for improving flow estimates at ungauged sites using various regionalization methods. The data set was the natural flow records of 40 stations on the island with record lengths of more than ten years. The research included a detailed assessment of the flow records, selection and computation or abstraction of appropriate flow and basin variables, analysis of the relationships of the flow measures to basin characteristics, grouping of the basins (for flood analysis only) into regions of geographic and basin characteristic dataspace, development of predictive equations for all groups, and assessment of the effectiveness of the regionalization methods. A procedure was developed in this work for estimating the effective precipitation in ungauged basins from geographic and topographic variables. -- The most important explanatory variables were found to be drainage area, area controlled by lakes and swamps, fraction of barren area in the basin, and distance of the basins north and/or southwest of defined lines. A detailed assessment of five methods of regional subdivision carried out using the mean annual maximum daily flow as the measure of interest found that dividing the island into regions generally improves the estimates at ungauged sites. Clustering based on basin characteristics is a promising method of regionalization.


identifier: Yi, Ul-Sung <https://research.library.mun.ca/view/creator_az/Yi=3AUl-Sung=3A=3A.html>   (1989) Stratigraphic and paleoenvironmental interpretation of coccoliths from ocean drilling program site 647, Labrador Sea.  Masters thesis, Memorial University of Newfoundland.

abstract: A total of 18 coccolith species was identified in the upper ca. 55 m of Ocean Drilling Program Site 647 Hole B (cores 1H to 6H) and the upper 1.1 m of gravity core Hudson 84-030-003. E. huxleyi Zone (NN 21), G. oceanica Zone (NN 20) and the upper part of P. lacunosa Zone (NN 19) were recognized at 0 to 11.1 m, 11.1 to 21.8 m and 21.8 to 56 m, respectively. The biostratigraphic zones were identified primarily based on the FAD of E. huxleyi and the LAD of P. lacunosa which are found to occur at the lowermost part of oxygen isotopic stage 7 and at the lowermost part of oxygen isotopic stage 12. -- Total floral record indicated that i) glacial and interglacial stages are characterized by minimum and maximum coccolith abundances, respectively; ii) early phases of several glacial stages are characterized by relatively high coccolith abundances; and iii) a few glacial to interglacial stage transitions are barren of coccoliths. These barren zones may be the result of dilution by terrigenous sediments or/and the result of suppressed biogenic carbonate productivity by the input of low-salinity and low-nutrient melt waters during deglaciation. The floral assemblages indicated that the study area was dominated by subpolar and transitional water-masses from 0 to ca. 0.472 Ma (oxygen isotopic stages 1 to 12/13) and by transitional water-masses from ca. 0.472 to ca. l.076 Ma (isotopic stages 12/13 to 35/36). The floral assemblage data also showed that early phases of several glacial stages are characterized by the presence of transitional or subpolar water-masses, indicating possible northward advection of warm North Atlantic water during the initial period of Northern Hemisphere ice sheet growth. -- R-mode cluster and factor analyses recognized an environmentally significant floral group consisting of C. pelagicus, E. huxleyi and G. oceanica. The floral group may reflect possible interactions between the cold Labrador Current and the warm North Atlantic Drift or coexistence of the two currents in the southern Labrador Sea during the interval studied. Q-mode cluster analysis recognized the most significant floral change slightly above the top of Jaramillo magnetic event, ca. 0.91 Ma when the dominant species, C. doronicoides was replaced by G. caribbeanica. It is interesting to note that the stratigraphic level marked by this floral change approximately coincides with the mid-Pleistocene interval ca. 0.9 to 0.6 Ma marked by the shift in climatic response of the North Atlantic from 41,000 years to 100,000 years periodicities (Ruddiman, Backman et al., 1987).


identifier: Meana, Lourdes <https://research.library.mun.ca/view/creator_az/Meana=3ALourdes=3A=3A.html>   (1991) Spatio-temporal trends of fertility decline in Newfoundland, 1966-1981.  Masters thesis, Memorial University of Newfoundland.

abstract: Age-specific fertility rates are not available for Newfoundland because the birth registration record does not include the age of the mother. However, age-specific fertility rates can be estimated from the administrative records of the hospital. This study estimates age-specific fertility rates and a number of derivative indexes from hospital records for prescribed areas on the island for the census years 1966 through 1981. The findings of this study reveal a large degree of spatial variation in fertility in 1966. The subsequent fifteen years are a period of extensive decline in fertility as rates converge toward a much lower family size norm. The spatio-temporal patterns of fertility decline reveal that Catholicism has presented a formidable barrier to the adoption of family limitation. The findings also reveal very significant spatial differences in teenage fertility rates and marriage patterns based on religion and the urban-rural distinction.


identifier: Li, Guoqing <https://research.library.mun.ca/view/creator_az/Li=3AGuoqing=3A=3A.html>   (1994) Simulating interdecadal variation of the thermohaline circulation by assimilating time-dependent surface data into an ocean climate model.  Masters thesis, Memorial University of Newfoundland.

abstract: We explore the feasibility of simulating interdecadal variations of the temperature, salinity and thermohaline circulation in the North Atlantic using an ocean general circulation model (OGCM) driven by time-dependent surface data. The natural way to drive the ocean is to use the surface heat and freshwater fluxes. In this thesis, we investigate the alternative of using surface temperature and salinity data since compared to heat and freshwater flux data, they are more accurate and more readily available. -- We do the experiments using idealized North Atlantic sized box geometry. In order to obtain a set of interdecadally-varying data, we first reproduced the results described by Zhang, Greatbatch and Lin (1993). Temperature, salinity, surface heat and freshwater flux are output from this control run and serve as "observations" in the further experiments. -- We can apply either a restoring boundary condition or a flux boundary condition at the ocean surface. To simulate the interdecadal variations, there are four choices for the surface boundary conditions: i) flux conditions on both temperature and salinity; ii) restoring conditions on both temperature and salinity; iii) a restoring condition on temperature and a flux condition on salinity (mixed boundary conditions); and iv) a flux condition on temperature and a restoring condition on salinity ("reversed mixed" boundary conditions). The restoring boundary conditions are to be understood in a sense of data assimilation. -- The experiments show that all the choices work well except mixed boundary conditions. It is found that a correct simulation of the thermohaline circulation is necessary to obtain a correct distribution of the sub-surface variables. Under mixed boundary conditions, a positive feedback between the development of a freshwater cap and heat-loss reduction results in either a collapsed or violent overturning thermohaline circulation quite unlike what happens in the control run. So mixed boundary conditions are not suitable for interdecadal simulation studies. The use of both-restoring boundary conditions does not allow a freshwater cap to develop because the surface salinity is constrained by the use of the restoring condition on salinity. This guarantees a realistic thermohaline circulation and, consequently, a correct distribution of the sub-surface temperature and salinity. In contrast with mixed boundary conditions, "reversed mixed" boundary conditions work well. This is because both surface heat flux and surface salinity are controlled, breaking the positive feedback that occurs under mixed boundary conditions. -- A common feature of the successful experiments is that all of them have a correct surface heat flux distribution (prescribed or implied), whereas the surface salt flux may defer (though not significantly). This shows that whatever the boundary condition is, it is necessary to get the surface heat flux seen by the ocean correct in order to have a realistic thermohaline circulation. It also shows that controlling surface salinity is more important than getting every detail of the freshwater flux correct (fortunately, freshwater flux data are the poorest). The results show that we should use both-restoring boundary conditions or reversed mixed boundary conditions to simulate interdecadal variations of the thermohaline circulation.


identifier: Fox, Don (Donald Laughlin) <https://research.library.mun.ca/view/creator_az/Fox=3ADon_=28Donald_Laughlin=29=3A=3A.html>   (1992) Structure, metamorphism and tectonic setting of metasedimentary rocks and mafic-ultramafic inclusions in the Dashwoods subzone of the Dunnage zone, southwestern Newfoundland.  Masters thesis, Memorial University of Newfoundland.

abstract: The Dashwoods subzone of the Dunnage zone in southwestern Newfoundland is characterized by high grade metasedimentary schists and gneisses and disrupted ophiolite complexes (Annieopsquotch Complex and Long Range Mafic-Ultramafic Complex) all intruded by hornblende-biotite granodiorite to tonalite. A previously reported age of the granitoid rocks is 456 ± 3Ma. This study focuses on an area east of the Long Range Fault, on the western side of the Dashwoods subzone and contains all the major lithostratigraphic units characteristic of the Dashwoods subzone. -- Metasedimentary rocks are separated into two main units: metapsammites to the west and metapelites to the east. Mafic-ultramatic inclusions lie within shear zones in the metapelites and are interpreted to represent parts of a disrupted ophiolite suite. All rocks within the shear zones (both metapelite and mafic-ultramatic) are extensively retrogressed to greenschist facies mineral assemblages but evidence of a higher grade, amphibolite facies metamorphism is evident in rocks that have not been completely retrogressed. The mafic-ultramafic rocks are interpreted to have undergone the full range of metamorphism and deformation that has affected the metasedimentary rocks. Geothermobarometry calculations suggest that the higher grade metamorphic event may have reached temperatures in the order of 800°C with pressures in the order of 5 to 7 kbars. -- The metasedimentary rocks are correlated with the Fleur de Lys metasediments found in northeastern Newfoundland on the basis of similar stratigraphic position along the eastern edge of the miogeocline of eastern North America. An upper age of deposition of the metasediments is approximately middle Ordovician as constrained by the age of the granitoid rocks. Silurian mafic bodies in the Dashwoods subzone have not been affected by high grade metamorphism or high degree of deformation and the Dashwoods subzone had probably stabilized by late Ordovician to Silurian time.


identifier: Easton, R. M. <https://research.library.mun.ca/view/creator_az/Easton=3AR=2E_M=2E=3A=3A.html>   (1982) Tectonic Significance Of The Akaitcho Group, Wopmay Oreogen, Northwest Territories, Canada.  Doctoral (PhD) thesis, Memorial University of Newfoundland.

abstract: The early Proterozoic Akaitcho Group consists of 6 to 8 km of metasedimentary and metavolcanic rocks located in the central metamorphic core zone of the Wopmay, Orogen (Bear Province). In the northern part of the orogen, the following generalized stratigraphic sequence has been recognized: 1) a lower mainly basaltic sequence, 2) 1-2 km of arkosic turbidites intruded by sills of rhyolite porphyry, 3) basalt and rhyolite volcanic complexes, and 4) 1 to 2 km of pelite and tuffaceous sedimentary rocks, locally, intruded by gabbro sills. The Akaitcho Group is conformably overlain by the Odjick Formation, part of an inferred passive-continental margin sequence (the Epworth Group). -- Two types of chondrite-normalized REE patterns are present in the Akaitcho Group basalts: a sloping pattern similar to recent continental tholeiites, and a flat pattern similar to type II ocean tholeiites. The basalt geochemistry in the Akaitcho Group evolves from older, evolved continental tholeiites, through continental tholeiites, to younger oceanic tholeiites. The Akaitcho Group rhyolites are probably crustally-derived. REE patterns of the Akaitcho Group sedimentary rocks indicate that the arkosic turbidites were derived from a granodiorite source terrane (i.e. average continental crust), whereas the upper pelites were derived from a volcanic source terrane similar to the Akaticho Group volcanic complexes and a granodiorite source terrane. -- Bimodal volcanism (subalkaline basalt and rhyolite) in association with continent-derived sediments, the temporal evolution of the basalt geochemistry, and the similarity of the Akaitcho Group to recent rift sequences indicate that the Akaitcho Group was deposited in a rift. The stratigraphic position of the Akaitcho Group beneath the Epworth Group suggests that the Akaitcho Group is related to continental break-up along the western Slave Craton about 1.9 Ga. Zircon dates from central Wopmay Orogen indicate that sea-floor spreading associated with continental break-up was short-lived.


identifier: Colman-Sadd, S. P. <https://research.library.mun.ca/view/creator_az/Colman-Sadd=3AS=2E_P=2E=3A=3A.html>   (1974) The geologic development of the Bay d'Espoir area, southeastern Newfoundland.  Doctoral (PhD) thesis, Memorial University of Newfoundland.

abstract: Bay d'Espoir on the south coast of Newfoundland exposes a section across the southeastern marginal metamorphic belt of the Newfoundland Appalachians. Two major tectonostratigraphic divisions are recognized; in the south the Little Passage Gneisses of the older division (probably Precambrian), consisting of amphibolitic and psammitic gneisses intruded by tonalite, are overlain by metavolcanic and metasedimentary cover rocks of the younger division, the Baie d'Espoir Group (possibly Ordovician). The Little Passage Gneisses have been intruded post-tectonically by a megacrystic potash feldspar granite. Both this granite and the enclosing gneisses are extensively mylonitised and reconstituted close to the contact with the cover rocks and the gneissic foliations have been largely destroyed. -- The Baie d'Espoir Group has undergone two, regionally penetrative deformations, the second of which has produced a major recumbent south-east facing anticline, the Bay d'Espoir Nappe. These deformations are the cause of the mylonitised and reconstituted zone along the contact with the Little Passage Gneisses. Garnetiferous leucocratic granite and associated aplites and pegmatites have intruded the Little Passage Gneisses, the megacrystic granite, and the Baie d'Espoir Group after its first deformation but before its second; the intrusion coincided with the metamorphic climax of the Baie d'Espoir Group. Sheets of this garnetiferous granite have been tightly folded with the reconstituted gneisses near the contact with the cover. -- It is concluded that the gneisses form the basement to the Baie d'Espoir Group and that the contact is now tectonic. Deposition of the Baie d'Espoir Group was along a continental margin which was initially of Atlantic-type but later changed to Andean-type. Deformation was probably caused by continental collision along the line of the Cape Ray Fault and the Lower Palaeozoic outcrop of central Newfoundland. Correlations with similar rocks in the Gander region, central Newfoundland, on the southwest coast of Newfoundland, and in Nova Scotia are proposed.


identifier: Gollop, Alison <https://research.library.mun.ca/view/creator_az/Gollop=3AAlison=3A=3A.html>   (2003) Structural controls on the seismic sequence stratigraphy of the Ben Nevis, Avalon, and Eastern Shoals formations, Terra Nova field, Jeanne D'Arc Basin, offshore Newfoundland.  Masters thesis, Memorial University of Newfoundland.

abstract: The structural controls on the seismic sequence stratigraphy of the lower Cretaceous succession in the Terra Nova oil field, Grand Banks of Newfoundland, is studied using a digital 3-D seismic database and wireline log data from 11 offshore wells. Three seismic sequences (Units A, B, and C) were mapped in the Terra Nova area, roughly corresponding to the Eastern Shoals, Avalon, and Ben Nevis formations, respectively. Each sequence is bounded by distinct unconformities. The development of these sequences and their boundaries was controlled by an interplay of sediment input, changes in sea level, tectonism, accommodation space, and climate. However, tectonism (i.e., fault-block subsidence and rotation) is interpreted to be the principal cause for the sedimentary patterns and development of the major unconformities in the Terra Nova field; global eustatic sea-level variations had only a minor influence on unconformity generation. -- The N-S-trending fault system in the Terra Nova field was active during the Tithonian to mid-Valanginian, as evidenced by fault growth within the Hibernia and Rankin formations. The E-W-trending fault system was previously interpreted to have been formed during mid-Aptian to Albian extensional phases; however, growth-strata patterns within the Eastern Shoals Formation suggest instead that the E-W-trending fault system in the Terra Nova field was initiated by at least the late Barremian and was active until late Albian. Also, the N-S-trending fault system in the Terra Nova field was reactivated at this time. This fault system terminates upward against the Albian unconformity, so that by late Albian the active rifting in the Terra Nova field is interpreted to have ceased. -- A "pop-up" feature immediately west of the Voyager Fault in the Terra Nova field has been previously interpreted to have formed by transpressional stresses induced by oblique-slip movement. However, geometries similar to those presented in the model of Jackson and Vendeville (1992 and 1994) suggest that a large salt diapir may lie in the footwall of the Voyager Fault. Therefore, an alternative interpretation is proposed for this "pop-up" feature, as a localized contractional feature related to diapirism. -- The lower Cretaceous succession in the Terra Nova field does not contain hydrocarbons, but forms reservoirs in other oil fields such as Hibernia and White Rose. It is proposed that the reservoir facies represented by the Ben Nevis and Avalon formations in the Terra Nova field were charged with hydrocarbons at some point but were subsequently breached, allowing oil to escape from the traps. This scenario is consistent with published fluid-inclusion studies.