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Showing 1 to 20 of 52 for “"clast"”.
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Experimental study of clast orientation in gravels deposited by unidirectional flow
Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Earth, Atmospheric, and Planetary Sciences, 1985.
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Clast cell activity in a model of aseptic root resorption / Craig William Dreyer.
Includes bibliographical references (leaves 355-403)
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Geochemistry of the Sykesville diamictite in central Maryland: an investigation of clast-matrix activity during metamorphism with tectonic implications
… matrix and pelitic schist and some felsic-gneiss clasts suggests that these inclusions were intrabasinally derived as first suggested by Fisher (1970). Zoned textures, compositional differences, and isotopic disequilibrium with the matrix exhibited by mafic schist, amphibolite, and …
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Geochemical and Paleontological investigations of the Neoproterozoic-Cambrian Transition: Case Studies on geochemical clast provenance, emerging paleo redox proxies, and ambiguous dubiofossils
… of this dissertation examines the carbonate clasts from a glacial diamictite deposited at the end of the Cryogenian Period in South China. By determining the source locality of those carbonate clasts using stable carbon and oxygen isotope compositions, we can better understand the extent of …
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Thermal Modeling of Cooling Time of Submarine Dacite Lapilli Tuff: Brothers Volcano, Kermadec Arc
… rim. Expedition researchers analyzed samples for clast radius, density, thermal conductivity, and specific heat. This data was then entered into the heat transfer equation of a sphere to create a cooling curve model of a lapilli dacite clast from its initial eruption temperature to the Curie …
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Sedimentology of the Cape Town boulder beds
… Cape Town region. The cobble- to boulder-size clasts in these fossil beaches point to a genesis that can be linked to the erosion of local rocky shores during hurricanes and “super storms”. This mode of formation seems similar to the Pliocene fossil beaches located at different elevations …
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Characterization of clasts in the Glen Torridon region of Gale crater observed by the Mars Science Laboratory Curiosity Rover
Granule- to cobble- sized clasts in the Glen Torridon region of Gale crater on Mars were studied using data captured by the Mars Science Laboratory (MSL) Curiosity rover between martian days (’sols’) 2302 and 2593. The morphology and composition of clasts has the potential to reveal the nature and …
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Weichselian glaciations in the middle Notec River region, northwest Poland
… on correlation of stratigraphical position, clast lithology, fabrics and grain size composition of till units. The lithostratigraphy covers two glacial advances of presumed Weichselian (Vistulian) age. The ice flow pattern during these glacial events was reconstructed using directional …
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The sedimentology of coarse grained hyperconcentrated flow deposits within modern and ancient volcaniclastic and alluvial fan sequences
… hyperconcentrated flow deposits in the volcaniclastic environment of Mount Saint Helens. Hyperconcentrated flow deposits are generally homogeneous, matrix-supported, unstratified (except where defined by sub units), have sorting characteristics intermediate between debris flow and stream flow …
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The Dynamics of the Late Neogene Antarctic Ice Sheets in the Central Ross Sea using a Multianalytical Approach
… data was compared to neodymium isotope and clast lithology datasets from collaborators. Site U1522 shows three distinct provenance shifts from the late Miocene to the Pleistocene, two of which are coincident with Ross Sea Unconformities three and two. Late Miocene samples have abundant …
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Abrasion, transport and distribution of sediment in selected streams of Southern Ontario and Western New York /
… shifting accumulation zones for each finer clast size. The discharge required to initiate movement of 8 cm and 6 cm blocks in Cazenovia Creek is closely approximated by Baker and Ritter's equation. Incipient motion of blocks in Twenty Mile Creek is best predicted by Yalin's relation which is …
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Late Pleistocene Stratigraphy And Events In The Asbestos-valcourt Region, Southeastern Quebec
… provenance. Till geochemistry as well as till clast lithology and fabrics indicate that drift unit A was deposited by a glacier that was advancing westward from Appalachian outflow centers. However, the presence of some northwest-derived clasts in till of drift unit A provides evidence for an …
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Depositional history of the Black Mountain conglomerate, Mohave County, Arizona: Sedimentary response to Miocene extension
… extensional corridor to the Lake Mead area. Clastic sedimentary rocks in the basin are linked to the extension of the region; Documentation of the basin fill was conducted with the aim of determining whether sedimentary clasts can be tied to lithologies that are exposed along Wilson Ridge and …
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Fault rock evolution and fluid flow in sedimentary basins
… inversion event. Fracture arrays and narrow cataclastic zones outside the previously developed sealed domain provided pathways for the migration of mature hydrocarbons. The East Scapa Fault reactivated in a reverse sense, and also contains fault rocks which record the presence of hydrocarbons at …
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A Quantitative Analysis of the Geomorphic Agency of the Mud-Nesting Swallows in Central Texas
… yet to be analyzed for their role in mud and clast transport for use in nesting. This dissertation aims at quantifying this geomorphic process.
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Braided stream deposition and provenance of the Late Cretaceous-Paleocene(?) Canaan Peak Formation, Table Cliff and Kaiparowits Plateaus, southwestern Utah
… on bar tops during waning flow conditions; Clast imbrication and trough axis orientation measurements indicate east to northeast paleoflow directions; Canaan Peak Formation detritus was derived from erosion of highlands created by Cretaceous Servier-style thrust faulting to the west in …
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The Role of Geomorphic Features and Hydrologic Processes on Sediment Clusters in Gravel-Bed Rivers, Washington: A Field-Based Approach
… Clusters are defined as an obstacle or anchor clast(s) that impede the progress of two or more sediment particles, and are believed to be an important characteristic of the variable bed topography of gravel-bed rivers. Detailed field descriptions and digital photographs of clusters were used to …
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The possibility of an impact-related origin of quasi-conglomerate pseudotachylytes on Barra, Outer Hebrides, Scotland, an integrated study
… amount of pseudotachylyte (sensu stricto) versus clasts and host rock, with a resolution of up to a millimetre, and to document and illustrate structures and clast rotation. Thin sections were used for microstructural analyses by optical and electron beam microscopy. Stereographical data was …
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Evolution of the Kingman Arch, southern Nevada
… quartzite, and Paleozoic carbonate clasts. Studies of clast type and provenance, together with qualitative analysis of paleoflow indicators, suggest that sediment was eroded from the Kingman Arch and highlands to the west and transported to the east and northeast.
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The morphodynamics of a sand and gravel barrier, Southern Hawke Bay, North Island, New Zealand
… ridge show increasing coarse skewness. Coarser clasts become more bladed in the littoral drift, but on average, the percentages of spheres do not increase in the direction of littoral drift. Towards the high-energy environment, the oblate prolate index becomes more negative (increasingly …
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