Mudstones, commonly thought to be homogenous and boring, turn out to be quite complex. Recent work on shale-gas and tight-liquid development, along with research on climate records and modern continental shelves, have revealed mudstones to be so complicated as to almost defy understanding. Rather than recording settling from suspension under persistently low-energy and low-oxygen waters, mudstones reflect the complex interaction of biological production, decay, dissolution of fossils, influx of sediments from land, and alteration during burial. Work presented here by Kevin Bohacs and colleagues reveals ordered patterns in this complexity that can be differentiated quantitatively and used to make predictions of rock properties. It appears that, on marine continental shelves, myriad processes converge to deposit relatively few associations with commonly recurring rock properties at the meter to tens of meter scale. These associations can be related quantitatively to ancient depositional environments with characteristic sets of processes. Bohacs and colleagues then used these patterns of sedimentary features to infer corresponding modern regimes with similar sets of commonly recurring depositional processes and from that, develop appropriate templates for their map patterns. These results can be used to make more robust interpretations of the rock record and to map the distribution of natural resources.
A White Nile megalake during the last interglacial period
Timothy T. Barrows et al., Department of Geography, College of Life and Environmental Science, University of Exeter, Exeter, Devon EX4 4RJ, UK; email@example.com. Published online ahead of print on 6 Jan. 2014, http://dx.doi.org/10.1130/G35238.1.
The eastern Sahara Desert of Africa is on
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Geological Society of America