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Full-Text Articles in Life Sciences
Stable And Radiocarbon Isotopic Composition Of Dissolved Organic Matter In The Gulf Of Mexico, B. D. Walker, E. R. M. Druffel, J. Kolasinski, B. J. Roberts, X. Xu, B. E. Rosenheim
Stable And Radiocarbon Isotopic Composition Of Dissolved Organic Matter In The Gulf Of Mexico, B. D. Walker, E. R. M. Druffel, J. Kolasinski, B. J. Roberts, X. Xu, B. E. Rosenheim
Marine Science Faculty Publications
Dissolved organic carbon (DOC) is of primary importance to marine ecosystems and the global carbon cycle. Stable carbon (δ13C) and radiocarbon (Δ14C) isotopic measurements are powerful tools for evaluating DOC sources and cycling. However, the isotopic signature of DOC in the Gulf of Mexico (GOM) remains almost completely unknown. Here we present the first DOC Δ14C and δ13C depth profiles from the GOM. Our results suggest the Mississippi River exports large amounts of DOC with an anthropogenic “bomb” Δ14C signature. Riverine DOC is removed and recycled offshore, and some marine …
Sub-Ice Shelf Sediment Geochronology Utilizing Novel Radiocarbon Methodology For Highly Detrital Sediments, C. Subt, H. I. Yoon, K. C. Yoo, J. I. Lee, A. Leventer, Eugene W. Domack, Brad E. Rosenheim
Sub-Ice Shelf Sediment Geochronology Utilizing Novel Radiocarbon Methodology For Highly Detrital Sediments, C. Subt, H. I. Yoon, K. C. Yoo, J. I. Lee, A. Leventer, Eugene W. Domack, Brad E. Rosenheim
Marine Science Faculty Publications
Sub-ice shelf sediments near Larsen C ice shelf (LIS-C) show fine-scale rhythmic laminations that could provide a near-continuous seasonal-resolution record of regional ice mass changes. Despite the great potential of these sediments, a dependable Late Quaternary chronology is difficult to generate, rendering the record incomplete. As with many marginal Antarctic sediments, in the absence of preserved carbonate microfossils, the reliability of radiocarbon chronologies depends on presence of high proportions of autochthonous organic carbon with minimized detrital organic carbon. Consequently, acid insoluble organic (AIO) 14C dating works best where high productivity drives high sediment accumulation rates, but can be problematic …
Short Organic Carbon Turnover Time And Narrow 14C Age Spectra In Early Holocene Wetland Paleosols, Lael Vetter, Brad E. Rosenheim, Alvaro Fernandez, Torbjörn E. Törnqvist
Short Organic Carbon Turnover Time And Narrow 14C Age Spectra In Early Holocene Wetland Paleosols, Lael Vetter, Brad E. Rosenheim, Alvaro Fernandez, Torbjörn E. Törnqvist
Marine Science Faculty Publications
Paleosols contain information about the rates of soil organic carbon turnover when the soil was actively forming. However, this temporal information is often difficult to interpret without tight stratigraphic control on the age of the paleosol. Here we apply ramped pyrolysis/oxidation (Ramped PyrOx) 14C analyses to evaluate age spectra of transgressive early Holocene paleosols from the Mississippi Delta in southeastern Louisiana, USA. We find 14C age spectra from soil organic matter (SOM) in both paleosols and overlying basal peats that represent variability in age that is close to, or only slightly greater than, analytical uncertainty of 14C …