Temperate glaciation on a Snowball Earth: Glaciological and palaeogeographic insights from the Cryogenian Yuermeinak Formation of NW China. / Vandyk, Thomas Matthew; Wu, Guanghui; Davies, Bethan; Xiao, Yang; Li, Meng; Shields-Zhou, Graham; le Heron, Daniel.

In: Precambrian Research, 17.01.2019.

Research output: Contribution to journalArticle

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Abstract

Extreme glaciation is the hallmark of the Cryogenian Period and understanding the behaviour and configuration of its constituent ice bodies is essential for environmental reconstructions. Thermal regime is one of the most important controls of glacial behaviour and subglacially striated surfaces are one of the very few means of determining an ancient temperate thermal regime. Unfortunately, due to a preservational bias of basinal over subglacial facies and the fragility of mm-scale striae, these surfaces are rarely preserved. In this context we present sedimentological and detrital zircon detail of a fortuitously preserved Cryogenian (Marinoan) outcrop on the Tarim Craton, NW China. The Yuermeinak Formation preserves not only a subglacially striated surface and palaeotopography but also a thin locally developed subglacial facies, indicating grounded ice. The remaining formation reveals glacial retreat and deposition of predominantly supraglacially-sourced debris within a dynamic, open-water, ice-proximal proglacial environment. This debris comprises dropstone-bearing shales punctuated by turbidites to debrites. Integrating our findings with published hypotheses for the tectonic and palaeogeographic development of the Tarim craton, we are able to present a first attempt at reconstruction of the palaeogeographic context of the Marinoan glaciation on the northern Tarim margin.
Original languageEnglish
JournalPrecambrian Research
StateSubmitted - 17 Jan 2019

ID: 33081112