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Tectonics and Structure

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Full-Text Articles in Geology

Potential Field Modeling Across The Neodymium Line Defining The Paleoproterozoic-Mesoproterozoic Boundary Of The Southeastern Margin Of Laurentia, Rachel Lauren Durham Jan 2017

Potential Field Modeling Across The Neodymium Line Defining The Paleoproterozoic-Mesoproterozoic Boundary Of The Southeastern Margin Of Laurentia, Rachel Lauren Durham

Theses and Dissertations--Earth and Environmental Sciences

A zone of high magnetization along the SE margin of Paleoproterozoic Laurentia in the United States is indicated by magnetic anomaly data. The SE edge corresponds to the geochemical Neodymium mantle derivation model age (TDM) boundary and the entire anomaly overlies the Paleoproterozoic Mazatzal Province. Two-dimensional gravity and magnetic models across the Nd boundary are created with Moho constrained from receiver functions with gravity, sedimentary thickness and the base of the crustal magnetization. Upper crustal magnetization does not show strong variation across this boundary and much of the strong magnetization appears to lie in the middle crust. Using …


Spatiotemporal Slip Rate Variations Along Surprise Valley Fault In Relation To Pleistocene Pluvial Lakes, Brian N. Marion Jan 2016

Spatiotemporal Slip Rate Variations Along Surprise Valley Fault In Relation To Pleistocene Pluvial Lakes, Brian N. Marion

All Master's Theses

Using mapped paleoshoreline features with high-resolution topographic data and obtained radiocarbon dates on paleoshoreline tufas, I documented precise fault offsets of dated features over the last 25 ka along the Surprise Valley Fault (SVF). Fault offset measured in three lake sections within Surprise Valley ranged from 3.6 m in the southern section to 14.4 m in the central section. The offset paleoshorelines are dated to the late Pleistocene (<22 >ka) and were formed during the latest impoundment of pluvial Lake Surprise since the last glacial maximum. Slip rates vary along strike, assuming a fault dip of 68° with 0.25 ± …