New Approaches to Understanding the Mechanics of Burgess Shale-Type Deposits: From the Micron Scale to the Global Picture

Robert R. Gaines, Mary L. Droser
2005 The Sedimentary Record  
Cambrian Burgess Shale-type (BST) deposits are among the most significant deposits for understanding the "Cambrian explosion" because they contain the fossilized tissues of nonmineralized organisms and provide a substantially different window on the radiation of the Metazoa than is afforded by the more "typical" fossil record of skeletal parts of biomineralized organisms. Despite nearly a century of research, BST deposits remain poorly investigated as sedimentologic entities largely because
more » ... comprise fine-grained mudrocks. Here, we describe a new, integrative approach to understanding a single BST deposit, the middle Cambrian Wheeler Formation of Utah, which reveals a dynamic interplay of paleoenvironmental, paleoecologic, and sedimentologic/diagentic factors within a superficially homogeneous lithofacies.This millimeter-scale microstratigraphic and paleontologic approach is augmented by both outcrop and microscopic study.These types of data are applicable to issues of quite different scales, including micron-scale diagenetic processes involved in fossil preservation, organism-environment interactions and paleoecology of the early Metazoa, and regional and global controls on the distribution of BST deposits. The Sedimentary Record June 2005 | 5
doi:10.2110/sedred.2005.2.4 fatcat:3lrwo74lzncodeljtlg27ndxpm