Toward the Recognition of Biological Soil Crusts in the Rock Record: Key Features from the Studyof Modern and Cretaceous Examples
Published:January 01, 2012
H. Fitzgerald Malenda, Edward L. Simpson, Michael C. Wizevich, Sarah E. Tindall, 2012. "Toward the Recognition of Biological Soil Crusts in the Rock Record: Key Features from the Studyof Modern and Cretaceous Examples", Microbial Mats in Siliciclastic Depositional Systems Through Time, Nora Noffke, Henry Chafetz
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Biological soil crusts (BSCs) are ubiquitous and crucial components of modern dryland ecosystems and probably were the first community type to colonize the Precambrian land surface. BSCs are complex symbioses of eubacteria, cyanobacteria, green algae, mosses, lichens, and fungi. BSCs, having adapted to intense ultraviolet radiation and drastic variations in precipitation and temperature, have likely been prevalent in terrestrial environments since the Precambrian and are undoubtedly under-reported in the rock record. This is probably due to the crusts’ inconspicuous appearance and preservational taphonomy. In order to improve understanding of the diverse appearances of BSCs in sedimentary strata, this study reviews the biology, biologically produced structures, and morphological variation of modern BSCs using examples from Colorado Plateau BSC of southern Utah (Grand Staircase–Escalante National Monument). Sediment coring into modern BSCs identified a variety of pedogenic features. Simple compaction experiments on the cores illustrate the taphonomic destruction of pedogenic features. In addition, a comparison of the modern BSC features to those preserved in a Cretaceous BSC found in Utah demonstrates the utility of understanding the nature of the various stages of development of modern BSCs. These descriptions of potentially preserved expressions of BSCs should facilitate identification and separation of fossilized BSCs from other physical sedimentary structures.
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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.