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Paleobiology of a Neoproterozoic tidal flat/lagoonal complex: the Draken Conglomerate Formation, Spitsbergen

Published online by Cambridge University Press:  20 May 2016

A. H. Knoll ,
K. Swett  and
J. Mark
A. H. Knoll
Affiliation:
Botanical Museum, Harvard University, Cambridge, Massachusetts 02138
K. Swett
Affiliation:
Department of Geology, University of Iowa, Iowa City 52242
J. Mark
Affiliation:
Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, Massachusetts 02138
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Abstract

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Carbonates and rare shales of the ca 700–800 Ma old Draken Conglomerate Formation, northeastern Spitsbergen, preserve a record of environmental variation within a Neoproterozoic tidal flat/lagoon complex. Forty-two microfossil taxa have been recognized in Draken rocks, and of these, 39 can be characterized in terms of their paleoenvironmental distributions along a gradient from the supratidal zone to permanently submerged lagoons. Supratidal to subtidal trends include: increasing microbenthic diversity, increasing abundance and diversity of included allochthonous (presumably planktonic) elements, decreasing sheath thickness of mat-building organisms (with significant taphonomic consequences), and an increasing sediment/fossil ratio in fossiliferous rocks. Five principal and several minor biofacies can be distinguished. The paleoecological resolution obtainable in the Draken Conglomerate Formation rivals that achieved for most Phanerozoic fossil deposits. It documents the complexity and diversity of Proterozoic coastal ecosystems and indicates that both environment and taphonomy need to be taken into explicit consideration in attempts to understand evolutionary trends in the early fossil record. Three species, Coniunctiophycus majorinum, Myxococcoides distola, and M. chlorelloidea, are described as new; Siphonophycus robustum, Siphonophycus septatum, and Gorgonisphaeridium maximum are proposed as new combinations.

Type
Research Article
Information
Journal of Paleontology , Volume 65 , Issue 4 , July 1991 , pp. 531 - 570
Copyright
Copyright © The Paleontological Society 

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