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Reference
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| Title: |
Report on Referred Fossils
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1979
(11/19)
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This report deals with one sample from unnamed lacustrine sediments that formed behind a moraine of Itkillik II age during and following glacier retreat. |
| Report by: |
Rick Forester
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| Referred by: |
Tom D. Hamilton
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| | Age: | Quaternary |
| Formation: | Unnamed |
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| Comment: | The sample was processed for calcareous microfossils and found to contain a few ostracodes and other organisms.
Bistratigraphy
Cypria opthalmica range is unknown, but it probably existed throught the Quaternary. It is a thin valved weakly calcified ostracode that is not readily preserved. The latter factor suggests, but does not demonstrate, a very young age for these sediments.
Paleoenvironment
Cypria opthalmica is a common ostracode occuring in the temperate to frigid climatic belts of the Northern Hemisphere. It is primarily a detrital feeder and, lives in both shallow and deep water. It is known from small, temporary pools and ponds as well as larger lacustrine systems. C. opthalmica lives in fresh (less than 3 ppt TDS) water that is slightly acidic to alkaline (pH about 6 to 10). Based on recently obtained information from cores in Yukon lakes and ponds C. opthalmica is often one of the first ostracodes to appear in newly formed aquatic environments.
The presence of this ostracode probably indicates very cold water. Based on trap experiments in Lake Itasca, Minn. it tended to occur most commonly during the winter months and was not present during July thought October. No other paleoenvironmental information is available for this ostracode. |
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