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Cyclic change in late triassic lacustrine communities
Science (New York, N.Y.)
|August 25, 1978
Summary
Late Triassic lake ecosystems in North Carolina and Virginia reveal cyclic patterns of life and extinction. These ancient meromictic lakes experienced repetitive development and demise, evidenced by fossil assemblages.
Area of Science:
- Paleontology
- Sedimentology
- Paleoecology
Background:
- The Dan River Group in North Carolina and Virginia contains Late Triassic sedimentary rocks.
- Understanding ancient lake ecosystems provides insights into past environmental conditions and evolutionary processes.
Purpose of the Study:
- To characterize a newly discovered lake and shore fossil assemblage from the Late Triassic Dan River Group.
- To investigate the relationship between sedimentary cycles and faunal/floral changes in these ancient lakes.
Main Methods:
- Systematic paleontological analysis of fossil remains (aquatic reptiles, fishes, insects, crustaceans, flora).
- Sedimentary facies analysis to identify and interpret depositional cycles.
- Correlation of fossil occurrences with identified sedimentary cycles.
Main Results:
- Discovery of a diverse fossil assemblage including aquatic reptiles, fishes, diverse insects, crustaceans, and flora.
- Identification of cyclic sedimentary patterns within the Dan River Group rocks.
- Correlation between faunal and floral changes and sedimentary cycles, indicating repetitive lake dynamics.
Conclusions:
- The fossil record indicates the repeated formation and extinction of large meromictic lakes during the Late Triassic in the Dan River basin.
- Sedimentary and fossil evidence points to cyclical environmental changes influencing lake ecosystems.
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