Abstract
Did early land plants produce a stepwise-change in atmospheric oxygen during the Late Ordovician (Sandbian nearly equal 458 Ma)?
Abstracts with programs - Geological Society of America, Vol.51(5)
Geological Society of America, 2019 annual meeting & exposition
09/2019
DOI: 10.1130/abs/2019AM-338453
Abstract
A stepwise-change in atmospheric oxygen (O (sub 2) ) levels during the Ordovician has been attributed to the emergence of land plants. This phenomenon is tied to a major baseline shift in the stable carbon isotope (delta (super 13) C (sub carb) ) curve, and an inferred increase in nutrient delivery, and enhanced primary productivity in nearshore settings, which led to enhanced organic carbon burial. The timing and magnitude of this baseline shift, however, is still elusive in part due to the lack of high-resolution delta (super 13) C data that span this period. This study presents new high-resolution delta (super 13) C data from Middle to Upper Ordovician sections at Germany Valley (West Virginia) and Union Furnace (Pennsylvania) in the Central Appalachian Basin. The delta (super 13) C curves of the data from both sections are characterized by relative stability and low carbon isotope values (mean delta (super 13) C = -0.61 ppm) in the lower Sandbian, followed by a nearly equal 1.2 ppm shift toward more positive values (mean delta (super 13) C = +0.62 ppm) in the upper Sandbian. We propose that the positive shift represents a fundamental state change in the global carbon cycle that is coincident with a major diversification of early land plants (i.e., bryophytes). This shift in delta (super 13) C baseline supports a growing number of studies that interpret enhanced organic carbon burial rates served as a mechanism for the stepwise oxygenation of the atmosphere during the Late Ordovician.
Details
- Title: Subtitle
- Did early land plants produce a stepwise-change in atmospheric oxygen during the Late Ordovician (Sandbian nearly equal 458 Ma)?
- Creators
- Y. Datu Adiatma - The Ohio State UniversityMatthew R. SaltzmanSeth A. YoungElizabeth M. GriffithNevin P. KozikCole T. EdwardsStephen A. LeslieAlyssa M. Bancroft
- Resource Type
- Abstract
- Publication Details
- Abstracts with programs - Geological Society of America, Vol.51(5)
- Conference
- Geological Society of America, 2019 annual meeting & exposition
- Publisher
- Geological Society of America (GSA)
- DOI
- 10.1130/abs/2019AM-338453
- ISSN
- 0016-7592
- Alternative title
- Geological Society of America, 2019 annual meeting & exposition
- Language
- English
- Date published
- 09/2019
- Academic Unit
- Earth and Environmental Sciences; Iowa Geological Survey; IIHR--Hydroscience and Engineering
- Record Identifier
- 9984702711902771
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