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1	Petrography and Provenance of an Archean Conglomerate Manitou Lake Northwestern Ontario Teal, Suzanne E. 05 1900 (has links) <p> The Archean "Loose Pebble Bay" conglomerate, Manitou Lake, northwestern Ontario, contains a variety of clast types, not all of which can be readily ascribed to local lithologies. This study was undertaken to determine the modal clast composition of the conglomerate, and investigate the origin of the clasts. The conglomerate lies near the top of a stratigraphic sequence which includes mafic and felsic volcanic rocks, iron formations, conglomerates, sandstones and argillites. The conglomerate unit itself consists of interbedded conglomerate and sandstone, and probably represents a channel-fill deposit of an ancient submarine fan.</p> <p> Modal percentages of clast types were obtained using a line-intercept method. They indicate that most of the debris in the conglomerate can be reasonably attributed to uplift and erosion of the lateral equivalents of the underlying stratigraphy, except for the granitoid clasts, which have no known origin within the area.</p> <p> Petrographic examinations of the clasts indicate that field identifications must be confirmed with thin section investigations.</p> <p> The modal composition of granitoid clasts was determined utilizing both thin sections and stained slabs. Most of the granitoid clasts are granodiorite, or lie just within the granite field, adjacent to the granodiorite field. Textural studies of the granitoid clasts suggest that gneissic and allotriomorphic-granular textured rocks may have formed by deformation or partial recrystallization along grain boundaries of previously hypidiomorphic-granular rocks. Textures generally indicate intrusive origin and slow cooling, although two granophyric samples may have solidified at relatively shallower depths than the other granitoid rocks.</p> <p> The textures and compositions of most of the granitoid clasts suggest that they were derived from one intrusive body. Intrusion of such a body into the volcanic-sedimentary belt, followed by uplift and erosion, would account for the presence in the "Loose Pebble Bay" conglomerate of granitic clasts and clasts similar to the underlying rocks. However, no evidence of such an intrusion has been found in the Manitou Lake area, and two of the granitoid clasts are noticeably different in composition from the others. The possibility of a pre-existing sialic basement cannot be ruled out.</p> / Thesis / Bachelor of Science (BSc)
2	The terraces of the Conway Coast, North Canterbury: Geomorphology, sedimentary facies and sequence stratigraphy McConnico, Tim January 2012 (has links) A basin analysis was conducted at the Conway Flat coast (Marlborough Fault Zone, South Island, New Zealand) to investigate the interaction of regional and local structure in a transpressional plate boundary and its control on basin formation. A multi-tiered approach has been employed involving: (i) detailed analysis of sedimentary deposits; (ii) geomorphic mapping of terraces, fault traces and lineaments; (iii) dating of deposits by 14C and OSL and (iv) the integration of data to form a basin-synthesis in a sequence stratigraphy framework. A complex thrust fault zone (the Hawkswood Thrust Fault Zone), originating at the hinge of the thrust-cored Hawkswood anticline, is interpreted to be a result of west-dipping thrust faults joining at depth with the Hundalee Fault and propagating eastwards. The faults uplift and dissect alluvial fans to form terraces along the Conway Flat coast that provide the necessary relief to form the fan deltas. These terrace/fan surfaces are ~9 km long and ~3 km wide, composite features, with their upper parts representing sub-aerial alluvial fans. These grade into delta plains of Quaternary Gilbert-style fan deltas. Uplift and incision have created excellent 3D views of the underlying Gilbert-style fan delta complexes from topsets to prodelta deposits. Erosive contacts between the Medina, Rafa, Ngaroma and modern Conway fan delta deposits, coupled with changes in terrace elevations allow an understanding of the development of multiple inset terraces along the Conway Flat coast. These terraces are divided into five stages of evolution based on variations in sedimentary facies and geomorphic mapping: Stage I involves the uplift of the Hawkswood Range and subsequent increased sedimentation rate such that alluvial fans prograded to the sea to form the Medina fan delta Terrace. Stage II began with a period of incision, from lowering sea level or changes in the uplift and sedimentation rate and continued with the deposition of the Dawn and Upham fan deltas. Stage III starts with the incision of the Rafa Terrace and deposition of aggradational terraces in the upper reaches. Stage IV initiated by a period of incision followed by deposition of estuarine facies at ~8ka and Stage V began with a period of incision and continues today with the infilling of the incised valley by the modern fan delta of the Conway River and its continued progradation. New dates from within the Gilbert-type fan deltas along the Conway Flat coast are presented, using OSL and 14C dating techniques. Faulting at the Conway Flat coast began ~ 94 ka, based on the development of the Medina Terrace fan delta with uplift rates ~1.38~1.42 m/ka. The interplay of tectonics and sea level fluctuations continued as the ~79 ka Rafa Terrace fan deltas were created, with uplift rates calculated at ~1.39 m/ka. Detailed 14C ages from paleoforest (~8.4-~6.4 ka) in the Ngaroma Terrace and from the mouths of smaller streams have established uplift rates during the Holocene ~1-3 m/ka, depending on sea level. Gilbert-type Fan Deltas Hawkswood Thrust Fault Zone Marlborough Fault Zone Sequence Stratigraphy Clast Imbrication Fabric Sediment Gravity Flows Foreset Processes Slumps Incision Terrace Geomorphology Geomorphic Mapping Conway Flat Coast New Zealand
3	Geology of the Phil Pico Mountain Quadrangle, Daggett County, Utah, and Sweetwater County, Wyoming Anderson, Alvin D. 25 April 2008 (has links) (PDF) Geologic mapping in the Phil Pico Mountain quadrangle and analysis of the Carter Oil Company Carson Peak Unit 1 well have provided additional constraints on the erosional and uplift history of this section of the north flank of the Uinta Mountains. Phil Pico Mountain is largely composed of the conglomeratic facies of the early Eocene Wasatch and middle to late Eocene Bridger Formations. These formations are separated by the Henrys Fork fault which has thrust Wasatch Formation next to Bridger Formation. The Wasatch Formation is clearly synorogenic and contains an unroofing succession from the adjacent Uinta Mountains. On Phil Pico Mountain, the Wasatch Formation contains clasts eroded sequentially from the Permian Park City Formation, Permian Pennsylvanian Weber Sandstone, Pennsylvanian Morgan Formation, and the Pennsylvanian Round Valley and Mississippian Madison Limestones. Renewed uplift in the middle and late Eocene led to the erosion of Wasatch Formation and its redeposition as Bridger Formation on the down-thrown footwall of the Henrys Fork fault. Field observations and analysis of the cuttings and lithology log from Carson Peak Unit 1 well suggest that initial uplift along the Henrys Fork Fault occurred in the late early or early middle Eocene with the most active periods of uplift in the middle and late Eocene (Figure 8, Figure 24, Appendix 1). The approximate post-Paleocene throw of the Henrys Fork fault at Phil Pico Mountain is 2070 m (6800 ft). The Carson Peak Unit 1 well also reveals that just north of the Henrys Fork fault at Phil Pico Mountain the Bridger Formation (middle to late Eocene) is 520 m (1710 ft) thick; an additional 460 m (1500 ft) of Bridger Formation lies above the well on Phil Pico Mountain. Beneath the Bridger Formation are 400 m (1180 ft) of Green River Formation (early to middle Eocene), 1520 m (5010 ft) of Wasatch Formation (early Eocene), and 850 m (2800 ft) of the Fort Union Formation (Paleocene). Stratigraphic data from three sections located east to west across the Phil Pico Mountain quadrangle show that the Protero-zoic Red Pine Shale has substantially more sandstone and less shale in the eastern section of the quadrangle. Field observations suggest that the Red Pine Shale undergoes a facies change across the quadrangle. However, due to the lack of continuous stratigraphic exposures, the cause of this change is not known. Eocene Red Pine Shale Uinta Mountains Bridger Formation Wasatch Formation Henrys Fork Fault Uplift uplift history anticline syncline Laramide Green River Formation Bishop Conglomerate inverted cobble stratigraphy unroofing unroofing sequence conglomerate Phil Pico Mountain Flaming Gorge Utah Wyoming Paleocene clast erosional history north flank facies change strike-slip fault Madison Limestone Weber Sandstone Vr VrTwo VrOne geologic mapping geology glacial deposits Smiths Fork Uinta thrust cuttings lithology log erosion Carson Peak well geologic map cross-section stratigaphy stratigraphic column unit descriptions tectonic history Tertiary depositional deposition Proterozoic Precambrian Geology

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