Abstract
Effects of coal deposition on carbon isotopes; Milankovitch cyclicity, eustacy, and the carbon cycle
Abstracts with programs - Geological Society of America, Vol.37(7), p.483
Geological Society of America, 2005 annual meeting
10/2005
Abstract
Carbon isotope data were collected from 72 meters of Atokan age limestones in Arrow Canyon, Nevada. Samples were collected every 30 cm through cyclic carbonates that contained major and minor cycles. These data clearly show a periodicity close to the 400,000 year periodicity of the major coal units of the same age in the Appalachian Basin. The isotopic signal reflects the sequestration of organic matter as coal with highest values ( approximately +4ppm) occurring in lithologies indicative of deepest water, the same time coals were being deposited. Lowest delta (super 13) C values ( approximately 0ppm) occur in silty limestone interpreted to be wind driven silt that accumulated during glacial maxima. These data show the impact coal deposition had on the function of the carbon cycle and may speak to the anomalously low CO (sub 2) levels that have been modeled for the Pennsylvanian. These data also show how the function of the carbon cycle was altered by the presence of coal swamps. When compared to Cenozoic data the contrast is distinct. Modern ocean circulation dictates that glacial episodes have higher delta (super 13) C values associated with maximum ice, more vigorous upwelling and increased nutrient delivery. Interglacial episodes show the decrease in circulation and nutrient delivery as lower delta (super 13) C values. We attribute the difference between the Pennsylvanian example and the Cenozoic example to the inundation of the continents and a change in the rate of terrestrial sequestration.
Details
- Title: Subtitle
- Effects of coal deposition on carbon isotopes; Milankovitch cyclicity, eustacy, and the carbon cycle
- Creators
- Kate E Tierney - Ohio State University, Department of Geological Sciences Columbus, OH USA United StatesMatthew R Saltzman
- Resource Type
- Abstract
- Publication Details
- Abstracts with programs - Geological Society of America, Vol.37(7), p.483
- Conference
- Geological Society of America, 2005 annual meeting
- Publisher
- Geological Society of America (GSA)
- ISSN
- 0016-7592
- Alternative title
- Geological Society of America, 2005 annual meeting
- Language
- English
- Date published
- 10/2005
- Academic Unit
- Earth and Environmental Sciences
- Record Identifier
- 9984240897602771
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