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Full-Text Articles in Earth Sciences
Holocene Climate And Environmental History Of Laguna Saladilla, Dominican Republic, Maria Anne Caffrey
Holocene Climate And Environmental History Of Laguna Saladilla, Dominican Republic, Maria Anne Caffrey
Doctoral Dissertations
Stratigraphic analyses of lacustrine sediments provide powerful tools for reconstructing past environments. The records that result from these analyses are key to understanding present-day climate mechanisms and how the natural environment may respond to anthropogenic climate change in the future. This doctoral dissertation research investigates climate and environmental history at Laguna Saladilla (19° [degrees] 39' N, 71° [degrees] 42' W; ca. 2 masl), a large (220 ha) lake along the north coast of Hispaniola. I reconstructed changes in vegetation and environmental conditions over the mid to late Holocene based on pollen, microscopic charcoal, and diatoms in an 8.51 m sediment …
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 …