Duration and nature of the end-Cryogenian (Marinoan) glaciation
Abstract
The end-Cryogenian glaciation (Marinoan) is portrayed commonly as the archetype of snowball Earth, yet its duration and character remain uncertain. Here we report U-Pb zircon ages for two ash beds from widely separated localities of the Marinoan-equivalent Ghaub Formation in Namibia: 639.29 ± 0.26 Ma and 635.21 ± 0.59 Ma. These findings verify, for the first time, the key prediction of the snowball Earth hypothesis for the Marinoan glaciation, i.e., longevity, with a duration of ≥4 m.y. They also show that the nonglacial interlude of Cryogenian time spanned 20 m.y. or less and that glacigenic erosion and sedimentation, and at least intermittent open-water conditions, occurred 4 m.y. prior to termination of the Marinoan glaciation.
Citation
Prave , A R , Condon , D J , Hoffmann , K H , Tapster , S & Fallick , A E 2016 , ' Duration and nature of the end-Cryogenian (Marinoan) glaciation ' , Geology , vol. 44 , no. 8 , pp. 631-634 . https://doi.org/10.1130/G38089.1
Publication
Geology
Status
Peer reviewed
DOI
10.1130/G38089.1ISSN
0091-7613Type
Journal article
Description
This work was supported by NERC Isotope Geoscience Facility Steering Committee grant IP-1462-0514.Collections
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