Abstract
First documentation of early Wenlock Ireviken positive delta (super 13) C (sub CARB) excursion in the type area of the Niagaran provincial series; Irondequoit Limestone, Rochester Shale, Decew Dolomite, Gasport Dolomite, and Goat Island Dolomite are all Sheinwoodian (early Wenlock) in age
Abstracts with programs - Geological Society of America, Vol.37(5), p.79
Geological Society of America, North-Central Section, 39th annual meeting
05/2005
Abstract
A high-resolution delta (super 13) C (sub carb) stratigraphic study recently performed on strata of the Clinton and Lockport Groups in the Niagara River Power Project S-1 core (Lewiston, New York) resulted in the first-ever recognition in those strata of the most widely known and best-documented positive delta (super 13) C excursion of the Silurian, the Early Wenlock Ireviken Excursion. A sharp increase in the delta (super 13) C (sub carb) values (+2.96 per mil to +5.55 per mil) near the Rockway Dolomite/Irondequoit Limestone contact marks the base of the Ireviken Excursion in the upper part of the Clinton Group, for it is known to have begun shortly following the extinction of Pterospathodus amorphognathoides amorphognathoides (just above the Llandovery/Wenlock boundary), which has its highest representation in western New York in the uppermost Rockway or basal Irondequoit. Apart from a slight decease in values in the lower Rochester Shale, delta (super 13) C (sub carb) values are consistently around +5.00 per mil in the Irondequoit Limestone, Rochester Shale, and DeCew and Gasport Dolomites. delta (super 13) C (sub carb) values gradually return to baseline (approximately +2.50 per mil) in the lower part of the Goat Island Dolomite (Niagara Falls Member), marking the end of the Ireviken Excursion. The Ireviken Excursion is known to end within the middle Sheinwoodian Kockelella walliseri Zonal Group, a zone based on the range of the nominative species. That species has its highest representation in the lower part of the Ancaster Member of the Goat Island in western New York, just slightly above the level at which delta (super 13) C (sub carb) values return to baseline. Since the Ireviken Excursion began in the earliest Sheinwoodian and ended well before the end of the Sheinwoodian, all of the strata containing a record of that excursion in western New York must also be Sheinwoodian (Early Wenlock) in age. A steady decline in delta (super 13) C (sub carb) values of nearly 5.00 per mil from baseline is recorded in the Ancaster and Vinemount Members of the Goat Island through the lower Eramosa Dolomite. A steady decline in delta (super 13) C (sub carb) values continuing well after the Ireviken Excursion has never previously been documented, and remains enigmatic until further study.
Details
- Title: Subtitle
- First documentation of early Wenlock Ireviken positive delta (super 13) C (sub CARB) excursion in the type area of the Niagaran provincial series; Irondequoit Limestone, Rochester Shale, Decew Dolomite, Gasport Dolomite, and Goat Island Dolomite are all Sheinwoodian (early Wenlock) in age
- Creators
- Mark A Kleffner - Ohio State University, Department of Geological Sciences Lima, OH USA United StatesBradley D CramerM. M Saltzman
- Resource Type
- Abstract
- Publication Details
- Abstracts with programs - Geological Society of America, Vol.37(5), p.79
- Conference
- Geological Society of America, North-Central Section, 39th annual meeting
- Publisher
- Geological Society of America (GSA)
- ISSN
- 0016-7592
- Alternative title
- Geological Society of America, North-Central Section, 39th annual meeting
- Language
- English
- Date published
- 05/2005
- Academic Unit
- Earth and Environmental Sciences; International Programs; Office Of The Provost
- Record Identifier
- 9984240890102771
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