The Hudson-James Bay Lowlands (HJBL) are composed of fens and bogs frequently intersected by rivers and punctured by bioherms (ancient reef mounds) rising from bedrock aquifer. The peatlands exist partly due to minimal vertical losses limited by the low hydraulic conductivity (K) of the Tyrrell Sea sediments and small vertical gradients between the surface and bedrock aquifers. The recent development of an open-pit mine; DeBeers Victor Diamond Mine within the HJBL requires dewatering of the regional limestone aquifer to a depth of 200 mbgs. Two major components in assessing the potential impacts of dewatering on the hydrogeological regime and the sensitive peatland ecosystem are: the characteristics and behaviour of the Tyrrell Sea aquitard, and bioherms as potential recharge enhancing features. The Victor Tyrrell Sea (VTS) deposits are clayey silt with low LL, low PI, and no smectite clay minerals. The clay fraction consists of quartz, illite, chlinochlore, and usually calcite. The deposits are normally consolidated with Cc values of 0.08-0.155 and void ratios of 0.52-0.77. The VTS deposits are grey with pockets of black graphite and frequent shells. The K rages from 6.6x10-9 to 4.7x10-8 m/s. GEO-SLOPE™ finite element modeling software was used to investigate the sensitivity of surface drainage and consolidation behaviour in regard to the range of measured VTS parameters. The behaviours were also compared to classic clay aquitard types such as Lake Agassiz and Lake Champlain. Unit thickness, K, and the K modifier function have the greatest impact on the rate and magnitude of consolidation, and vertical drainage of the surface. The K of the underlying till is extremely important because they can be a buffer between the dewatered bedrock aquifer and the VTS. The characteristics of the sediments and the flow regime surrounding three outcropping bioherms which increase vertical drainage are investigated and a conceptual model of flow is proposed. The sediments in profile around bioherms have different levels of stratification but always contain silt and sand units. The hydraulic conditions at eight nested piezometers and the stratigraphy as defined by a series of auger hole profiles was considered to develop a conceptual model. The flow regime presented is of radial flow towards the bioherms enhanced by high K sediments between the peat and bedrock becoming vertical flow when the high K sediments contact vertical channels in the rock. / Thesis (Master, Geological Sciences & Geological Engineering) -- Queen's University, 2013-02-06 14:47:13.582

<p> Bioherm growth within the Edgecliff Member of the Onondaga Formation in the vicinity of Port Colborne, Ontario is represented by a broad low-lying coralliferous mound, trending approximately north-south. The mound displays a progressive pattern of faunal and lithologic succession which can be broken down into four stages. The Basal and Coral-Rich Basal Facies represents deposition in a shallow to deep shelf lagoon, below fair weather wave base and above storm wave base. Stage I of mound development is initiated in response to a slight regression near the top of these facies, corresponding to the deposition of the Transitional Facies, a shoaling upwards sequence reaching above the surrounding substrate. stage II is represented by the colonization and stabilization of the mound by solitary and colonial corals within fair weather wave base. Stage III results in the diversification of the mound upwards into a high energy zone, corresponding to the deposition of the Core Facies. At this time, sea-level remains stable and intermound areas are filled in by the Biostrome, Flank, and Flank/Cap Facies. The final stage, Stage IV represents the termination of mound growth by deposition of a crinoidal cap due to, either a fall in sea-level, or growth of the mound into the surf zone.</p> <p> The inferred paleocurrent direction from facies relationships, and a measured coral orientation, suggest currents direction from the southeast to northwest.</p> <p> Thus, the Edgecliff Member of the Onondaga Formation in the vicinity of Port Colborne, Ontario represents deposition in a shallow shelf lagoon, and displays evidence for two possible sea-level fluctuations; one near the top of the Basal and Coral-Rich Basal Facies, and the second corresponding the Flank/Cap and Cap Facies, terminating mound development.</p> / Thesis / Bachelor of Science (BSc)

No description available.

The colloquially named leopard rock of the Holder and Laborcita formations (Late Pennsylvanian-Early Permian) is an algal/foraminiferal boundstone that occurs within a cyclic, interfingered, carbonate siliciclastic system in the Sacramento Mountains of southeastern New Mexico) and often accompanies phylloid algal mounds. This project is the first to fully characterize and evaluate the evidence that leopard rock is microbial in origin and assess the potential influence of methane seeps and deltaic organics on its genesis. Characterization of the algal-foraminiferal boundstone revealed a highly variable expression in outcrop based on geolocated photo imagery, hand samples, optical microscopy, and scanning electron microscopy (SEM) data. Leopard rock is interpreted as microbial in origin based upon all features observed in aggregate, particularly upward-oriented concentric gradational laminae and striking clusters of segmented curvilinear cylinders (~1000 nm long). Leopard rock is best described as thrombolytic. A comprehensive categorization into thrombolite types was conducted and field and analytical data were used in creating a geospatial data base. The data was evaluated spatially in ArcMap for co-occurrence, trends, and possible associations within, and between, categorizations and formations. Distribution and associations of dome (1-3 m), small coniform (< 1 m), and planar outcrop structures and thrombolite types reflect a hierarchy of complexity and prevalence that would be expected from a microbial system. An extensive multi-scale feature comparison of potential modern analogues from Australia, the Bahamas, and Canada, in conjunction with contiguous paleo-analogues, support the interpretation of a highly adaptable complex microbial ecosystem. Results were also consistent within the global chemical, biologic, and physical context at the time of deposition. Evidence for methane seep contribution support the plausibility of supplemental microbial energy sources based on modern examples and limited paleo-analogues. Stratigraphic position and a paucity of data do not support a significant role for deltaic bathymetry or organic influx in leopard rock genesis. The results of this study provide robust evidence that leopard rock is a multi-faceted complex microbial thrombolite that displays a continuum of expression not represented by one all-encompassing term and illustrates the value of multi-parameter analyses augmented across time and space using analogues and geospatial software.

No description available.