Physical Sciences and Mathematics Commons^™

Assessing Diagenetic Conditions In The Late Triassic Chinle Formation Through Petrographic And Geochemical Analysis Of Phytosaur Teeth, John Fortner

Earth Sciences Theses and Dissertations

The Upper Triassic (Norian; ~227-208 Ma) Chinle Formation of Petrified Forest (PeFo) National Park was deposited during a time of major tectonic breakup and profound changes in atmospheric circulation and faunal compositions. Little has been done however to assess whether surficial paleoenvironmental trends related to deterioration of the Late Triassic Megamonsoon resulted in similar trends in the early diagenetic environment. Here, we use phytosaur tooth dentin as a proxy for diagenetic conditions in the Chinle of PEFO, as its greater susceptibility to chemical alteration relative to enamel makes it an excellent substrate from which changing diagenetic conditions may be studied …

Assessing Quaternary Geohazards In Hispaniola And Jamaica Using Seismic, Remote Sensing And Sediment Core Data, Vanshan Wright

Earth Sciences Theses and Dissertations

The Enriquillo-Plantain Garden Fault Zone (EPGFZ) is a system of predominantly left-lateral strike-slip faults extending through Eastern Jamaica and Western Hispaniola. The fault zone has generated at least one large (> Mw 6) earthquake per century within the last five centuries. These earthquakes include the 2010 Mw 7 Haitian earthquake which killed 300, 000 people and the 1907 Jamaican earthquake which killed ~900 people. Both earthquakes resulted in significant infrastructural damages, tsunamis, landslides and ground fissures.

This dissertation provides insights into the history, and societal impacts of active faulting and earthquake triggered geohazards within the EPGFZ. Herein, I show that …

Investigating Seismic Deformation Associated With The Aging And Subduction Of Oceanic Lithosphere Using Teleseismic Earthquake Relocation And Insar Techniques, Kevin Kwong

Earth Sciences Theses and Dissertations

Based on seismicity and deformation patterns, the evolution and subduction of oceanic lithosphere can be divided into three domains: 1) the incoming oceanic lithosphere plate, 2) the megathrust plate boundary, and 3) the down-going slab. Well-located hypocenters illuminate fault complexity in space and time and verify details of surface deformation within or associated with the subduction system. This dissertation presents high-resolution earthquake catalogs derived using teleseismic double-difference (DD) relocation to best resolve earthquakes in absolute space, while providing relative locations for more detail fault studies. In the Wharton Basin, a new earthquake catalog allows more detailed examination of complex oceanic …

Geochemical Analysis Of Soil And Lake Deposits As Indicators Of Paleoenvironmental Conditions; Examples From Texas, New Mexico, And D.R. Congo, Mary Milleson

Earth Sciences Theses and Dissertations

Geochemical proxies of paleoenvironmental conditions are presented from studies of modern lacustrine deposits from White Rock Lake, Dallas Texas, Upper Pennsylvanian through Lower Permian paleosols from Mora County New Mexico, and Upper Paleozoic lacustrine strata from the Congo Basin, D.R. Congo.

The composition of sedimentary organic matter of White Rock Lake is utilized to establish a temporal relationship between urbanization of the local watershed and lake system. Geochemical proxies of watershed conditions allow for the evaluation of changes in lake morphometry, which are correlated with historical records of urbanization. The δ¹³C and C/N values of sedimentary organic matter …