Does cement-induced sulfate limitation account for Burgess Shale-type preservation?

Abstract

In a recent PNAS paper, Gaines et al. (1) proposed a mechanism of early diagenetic sealing and oxidant limitation to account for the preservation of Burgess Shale-type (BST) fossils (i.e., the “exceptional” preservation of carbonaceous compression fossils in Cambrian-aged marine mudstones) (1). It is an interesting hypothesis, but it raises a number of issues.