Abstract 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.

Abstract The thickest and most laterally continuous upper Carboniferous molasse in the central Appalachians is located in the Southern Anthracite Field of northeastern Pennsylvania. Substantial deposits extend throughout northeastern Pennsylvania where >90% of the total anthracite (original reserves) in the United States and the thickest coal beds of the eastern United States are located. The abundance of and demand for this resource allowed the region to prosper in the nineteenth and twentieth centuries. In Pottsville, Pennsylvania, the exposed Upper Mississippian to Middle Pennsylvanian molasse reveals a progressive evolution from a semiarid alluvial plain to a semihumid alluvial plain to a humid alluvial plain. The anthracite beds occur and thicken with increased humid conditions. The progression is also exposed in Tamaqua, Pennsylvania, where convenient access to the underlying Lower Mississippian strata is available, thus providing a section of all Carboniferous formations in the region. Finally, in Lansford, Pennsylvania, a renovated deep anthracite mine illustrates the historical methods and working conditions that existed to extract the valuable resource and allow the region to flourish and fuel the Industrial Revolution.