Based on hafnium and oxygen isotope compositions of zircons up to 4.4 billion years in age, a study finds that the abrupt transition from crystalline basement to sedimentary rock at the end of the Proterozoic Eon, known as the Great Unconformity, may reflect rapid glacial erosion during late Proterozoic "snowball Earth" events that transferred sediment from the continents to ocean basins, where the sediment was recycled through subduction.
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Article #18-04350: "Neoproterozoic glacial origin of the Great Unconformity," by C. Brenhin Keller et al.
MEDIA CONTACT: C. Brenhin Keller, Berkeley Geochronology Center, CA; tel: 607-351-9811; e-mail: < cbkeller@berkeley.edu >
Proceedings of the National Academy of Sciences