Peritidal microbial assemblages from the Late Proterozoic limestone/dolomite series, central east Greenland
The Late Riphean (700-800 Ma) Limestone/Dolomite sequence of the East Greenland Caledonides comprises some 1100 meters of carbonates and minor interbedded siliciclastic units deposited in tidal flat to shallow subtidal marine environments. Several horizons within this succession contain exceptionally well preserved microfossil assemblages. Peritidal associations include: 1) the remnants of two distinct microbial mat communities containing Lyngbya- or Phormidium-like cyanobacterial mat builders and associated mat dwellers; 2) a microbenthic association dominated by populations morphologically and behaviorally indistinguishable from modern cyanobacteria assigned to the genus Cyanostylon; 3) thin horizons of Eoentophysalis which occasionally cap laminae of the previous association; and 4) endolithic microfossils preserved in silicified ooids and pisoliths. Fossil endoliths include one population that is morphologically, developmentally, and ecologically comparable to the modern cyanobacterium, Hyella gigas, and additionally contain several other fossil cyanobacterial and algal populations. The unusually good preservation of these assemblages, apparently associated with rapid burial during storms, permits reconstruction of some measure of the ecological dynamics of these several peritidal communities. Comparable microbial communities occur today in Bahamian peritidal environments. Such detailed knowledge of microbial paleoecology is necessary for realistic biostratigraphic and evolutionary evaluations of the Proterozoic fossil record.
- Research Organization:
- Harvard Univ., Cambridge, MA (USA)
- OSTI ID:
- 6201006
- Report Number(s):
- CONF-8510489-
- Journal Information:
- Geol. Soc. Am., Abstr. Programs; (United States), Vol. 17; Conference: 98. annual meeting of the Geological Society of America, Orlando, FL, USA, 28 Oct 1985
- Country of Publication:
- United States
- Language:
- English
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