Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 1 of 1
Full-Text Articles in Geology
Carbon And Sulfur Cycling In Early Paleozoic Oceans, Cara Kim Thompson
Carbon And Sulfur Cycling In Early Paleozoic Oceans, Cara Kim Thompson
Doctoral Dissertations
Here, I evaluate biospheric evolution during the Ordovician using high-resolution inorganic carbon and sulfur (carbonate-associated sulfate and pyrite) isotope profiles for Early Ordovician to early Late Ordovician strata from geographically distant sections in Western Newfoundland and the Argentine Precordillera. Additionally, I present new, high-resolution U-Pb ages for volcanic ash beds within strata of the Argentine Precordillera. Carbon isotope data record subdued variation that is typical of Early- to Middle Ordovician strata worldwide. By contrast, sulfur-isotopic compositions of carbonate-associated sulfate reveal a complex signal of short-term, rhythmic variation superimposed over a longer-term signal. This short-term, rhythmic variation occurs in all sections …