1997), although Nature did not acknowledge Berthault’s prior work (Snelling 1997).
Furthermore, these experimental results have been confirmed by field observations. Helens subsequent to the well-known May 18, 1980, eruption resulted in the formation of a 762 cm (25 feet) thick deposit consisting of many thin, alternating fine-grained and coarse-grained laminae very similar to varves.
However, recent research by Schieber, Southard and Thaisen (2007) and Schieber and Yawar (2009), using the Indiana University Flume Laboratory, has demonstrated that the commonly observed laminated mudrocks, so prevalent throughout the rock record and around the globe, formed by moving water, and energetic deposition.
Their experiments showed that mudrocks, and laminae in particular, form not by slow deposition out of a stagnant water column, but by flowing water at speeds of 0.3 m/sec (1 ft/sec).
This occurs because particles of different sizes have a tendency to spontaneously segregate and stratify themselves.