Microbial Mats in Siliciclastic Depositional Systems Through Time

The research field on microbial mats in siliciclastic environmental settings has greatly developed since its establishment by studies of pioneering scientists such as Gisela Gerdes, Wolfgang Krumbein, Jürgen Scheiber, David Bottjer and others. This SEPM Special Publication is the result of the SEPM Research Conference on Sandy Microbial Mats (modern and ancient), which was held in May 21-23, 2010 at Dinosaur Ridge, Denver, Colorado, USA. This volume presents peer reviewed individual case studies on microbial mats and on sedimentary structures (often called “microbially induced sedimentary structures-MISS”) that occur in modern and ancient marine and terrestrial environments. The conference brought together sedimentologists, microbiologists, and paleontologists from 30 countries and all five continents.
Witwatersrand Metallogenesis: The Case for (Modified) Syngenesis
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Published:January 01, 2012
Abstract
The Witwatersrand (WWR) ores contain more gold than could have been derived in particulate form by erosion from any conceivable type of source area as proposed by the modified placer hypothesis. In contrast to this, syngenesis goes further to explain a host of observations from those Late Archean Au-U ores. Although recycling, placer processes, and processes of hydrothermal (diagenetic/authigenic) mobilization all contributed, syngenesis was a major factor contributing to ore genesis in this huge metallogenic province. Over 80% of the gold occurs in the Main Reef and Bird Reef of the Johannesburg Subgroup in the Central Rand Group, and...