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Paying attention to mudrocks: Priceless!

New Special Paper from the Geological Society of America

Geological Society of America


IMAGE: Outcrop of the Union Springs Member of the Devonian Marcellus Formation. Photo by Lindell Bridges, courtesy Randy Blood, EQT Production. view more

Credit: Lindell Bridges, courtesy Randy Blood, EQT Production. Design by the Geological Society of America.

Boulder, CO, USA - Siliciclastic mudrocks, often termed shales, represent more than two thirds of all sedimentary rocks on Earth, yet they are the least understood. The topic of mudstone deposition and diagenesis has only recently begun to emerge as important and widely recognized, mostly because of increased interest from the petroleum industry. In spite of their fine grain-size rocks and low permeabilities, mudstones have contributed significantly to North American production of natural gas.

But it is not only the petroleum sector that has focused on the significance of mudstones: Clay minerals in fine-grained sediments are also sought after to provide raw materials incorporated into liners for landfills, both at the base as well as sealing the tops of them. They are also made into ceramics used in every household, they aid in the process of paper making, are an essential component for producing cement, and are even used in medicine. An understanding of shale sedimentology, the make-up of shales and muddy sediments from different environments, and modification of muddy sediments by post-depositional processes is therefore crucial for a wide variety of practical uses.

The case studies included in this new Special Paper from The Geological Society of America, edited by Daniel Larsen of the University of Memphis, Sven O. Egenhoff of Colorado State University, and Neil S. Fishman of the U.S. Geological Survey and Hess Corporation, cover two themes: The first focuses on mudstone deposition in several settings, and the second focuses on the diagenetic processes that have affected important mudstone units.


Individual copies of the volume may be purchased through The Geological Society of America online store,, or by contacting GSA Sales and Service,

Book editors of earth science journals/publications may request a review copy by contacting April Leo,

Paying Attention to Mudrocks: Priceless!
edited by Daniel Larsen, Sven O. Egenhoff, and Neil S. Fishman
Geological Society of America Special Paper 515
SPE515, 168 p., $55; GSA member price $38
ISBN 978-0-8137-2515-4
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