Science. 2007 Dec 14;318(5857):1760-3. doi: 10.1126/science.1147001.

Accretion of mudstone beds from migrating floccule ripples.

Science (New York, N.Y.)

Juergen Schieber, John Southard, Kevin Thaisen

PMID: 18079398 DOI: 10.1126/science.1147001

Abstract

Mudstones make up the majority of the geological record. However, it is difficult to reconstruct the complex processes of mud deposition in the laboratory, such as the clumping of particles into floccules. Using flume experiments, we have investigated the bedload transport and deposition of clay floccules and find that this occurs at flow velocities that transport and deposit sand. Deposition-prone floccules form over a wide range of experimental conditions, which suggests an underlying universal process. Floccule ripples develop into low-angle foresets and mud beds that appear laminated after postdepositional compaction, but the layers retain signs of floccule ripple bedding that would be detectable in the rock record. Because mudstones were long thought to record low-energy conditions of offshore and deeper water environments, our results call for reevaluation of published interpretations of ancient mudstone successions and derived paleoceanographic conditions.

Publication Types

• Journal Article
• Research Support, U.S. Gov't, Non-P.H.S.