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 …

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 …