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Theses/Dissertations

Geology

University at Albany, State University of New York

1981

Articles 1 - 6 of 6

Full-Text Articles in Physical Sciences and Mathematics

Geology Of The Plutonic And Hypabyssal Rocks Of The Betts Cove Ophiolite Complex, Newfoundland, Bruce D. Idleman Jan 1981

Geology Of The Plutonic And Hypabyssal Rocks Of The Betts Cove Ophiolite Complex, Newfoundland, Bruce D. Idleman

Geology Theses and Dissertations

The Betts Cove ophiolite complex lies within the Dunnage Zone island arc terrain of central Newfoundland. It forms the base of the lower Ordovician Snooks Arm Group, which consists of mafic igneous rocks of the ophiolite and a thick sequence of volcanic and volcaniclastic rocks which conformably overlies it. The Snooks Arm Group is unconformably overlain by sub-aerial sediments and volcanics of the presumed Silurian Cape St. John Group.
The base o£ the ophiolite complex consists predominantly of ultramafic rocks. These are interlayered on a variety of scales, and show mesoscopic igneous structures which suggest that they were produced by …

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Permo-Triassic Reconstruction Of Western Pangea And The Evolution Of The Gulf Of Mexico-Caribbean Region, James Lawrence Pindell Jan 1981

Permo-Triassic Reconstruction Of Western Pangea And The Evolution Of The Gulf Of Mexico-Caribbean Region, James Lawrence Pindell

Geology Theses and Dissertations

A Permo-Triassic reconstruction of western Pangea (North America, South America, Africa) is proposed that is characterized by: 1) definition of the North Atlantic fit by matching of marginal offsets (fracture zones) along the opposing margins, 2) a South Atlantic fit that is tighter than the Bullard fit and that is achieved by treating Africa as two plates astride the Benue Trough and related structures during the Cretaceous, 3) complete closure of the Proto-Atlantic Ocean between North and South America, accomplished by placing the Yucatan block between the Ouachita Mountains and Venezuela, 4) a proposed Hercynian suture zone that separates zones …

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Some Chemical And Mineralogical Aspects Of Plutonic Rocks From The North Arm Mountain Massif, Bay Of Islands Ophiolite, Newfoundland, Jerry W. Sullivan Jan 1981

Some Chemical And Mineralogical Aspects Of Plutonic Rocks From The North Arm Mountain Massif, Bay Of Islands Ophiolite, Newfoundland, Jerry W. Sullivan

Geology Theses and Dissertations

Whole-rock major and trace element compositions of one basalt, one diabase, and 21 rocks from the magmatic-plutonic units of the North Arm Mountain massif, Bay of Islands ophiolite, Newfoundland, were determined. Mineral compositions of a subset of the plutonic rocks were also determined.
The major and trace element compositions of the basalt and diabase are similar to abyssal tholeiites, and this is consistent with the REE data of Malpas (1978) and Suen, et. al. (1979) that suggest the lavas and dikes formed from a depleted or slightly enriched abyssal tholeiitic magma. The alkaline nature of the magma proposed by several …

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Geologic Investigations In The Cayman Trough And The Nature Of The Plutonic Foundation Of The Oceanic Crust, Janet B. Stroup Jan 1981

Geologic Investigations In The Cayman Trough And The Nature Of The Plutonic Foundation Of The Oceanic Crust, Janet B. Stroup

Geology Theses and Dissertations

A survey of the literature that deals with the gabbroic rocks believed to comprise the foundation of the oceanic crust indicates that the overwhelming majority of these rocks are recovered from escarpments associated with transform faults. The wide range of mineral and chemical compositions characterizing oceanic gabbroic rocks suggests that the lower oceanic crust is much more heterogeneous in nature than was previously suggested by the results of geophysical investigations. The examination of gabbroic rocks recovered in situ from the walls of the Mid-Cayman Rise rift valley by the submersible ALVIN not only supports the notion that oceanic gabbroic rocks …

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Structural Studies Of The Ordovician Flysch And Melange In Albany County, New York, Frederick W. Vollmer Jan 1981

Structural Studies Of The Ordovician Flysch And Melange In Albany County, New York, Frederick W. Vollmer

Geology Theses and Dissertations

The middle Ordovician rocks of the Albany 15 minute quadrangle comprise interbedded graywacke and shale, and in the east, coarse cobble or olistostromic deposits. The detrital composition, westward fining and regional westward transgression of these deposits indicate that these were sediments shed off the westward thrusting Taconic Allochthon. Primary sedimentary structures show that these rocks were deposited by turbidity currents flowing into a longitudinal trough, probably formed in response to increased load during overthrusting. Although strongly dependent on lithology, deformation intensity generally increases from west to east; from essentially undeformed bedded flysch through asymmetrically folded and thrust beds to highly …

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Structural Analysis Of An Area Near Middlebury, Vermont, Paul A. Washington Jan 1981

Structural Analysis Of An Area Near Middlebury, Vermont, Paul A. Washington

Geology Theses and Dissertations

Detailed mapping of an area near Middlebury, Vermont, reveals a multiple deformational scheme quite different from that previously proposed. The published stratigraphy of the middle Ordovician limestones, on which earlier structural theories are based; was found to be inaccurate, so a new system has been defined. An unreported early generation of cleavage has been discovered which indicates the existence of a decollement zone in the upper Bascom formation. The second generation of cleavage and its associated folding were well defined by earlier workers, but this study shows that it is also a thin-skinned event.
The last deformation, as exhibited by …

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