Analysis of Proterozoic basement granite in the southern Colorado Front Range suggests that the granite underwent substantial erosion prior to the Snowball Earth glaciations 717 million years ago, implying that the Great Unconformity--a large gap in the geological record between the Proterozoic and Phanerozoic Eons--did not result from glacial erosion during the Snowball Earth in this area and may have formed at varying times in different locations, according to a study.
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Article #19-13131: "Diachronous development of Great Unconformities before Neoproterozoic Snowball Earth," by Rebecca M. Flowers, Francis A. MacDonald, Christine S. Siddoway, and Rachel Havranek.
MEDIA CONTACT: Rebecca M. Flowers, University of Colorado Boulder, CO; tel: 303-579-5887; e-mail: rebecca.flowers@colorado.edu
Proceedings of the National Academy of Sciences