Bird’s-eye view of an Ediacaran subglacial landscape

Abstract

Abstract Depositional evidence for glaciation (dropstones, diamictites) is common in Neoproterozoic strata, and often debated, but erosional evidence (e.g., unconformities cut directly by ice) is rare. Only two such unconformities are known to have been well preserved globally from the Ediacaran Period (in western Australia and central China). This paper provides the first full description of a spectacular subglacial landscape carved beneath ice masses in the Shimengou area of central China, with classical subglacial bed forms including general faceted forms, müschelbruche, cavetto, spindle forms, and striations that testify to an abundance of meltwater during subglacial erosion. These features were produced during the southward, somewhat sinuous, flow of a temperate to polythermal ice mass.