435: Estimating Duration and Intensity of Neoproterozoic Snowball Glaciations from Ir Anomalies -- Bodiselitsch et al. 308 (5719): 239 -- Science

Estimating Duration and Intensity of Neoproterozoic Snowball Glaciations from Ir Anomalies -- Bodiselitsch et al. 308 (5719): 239 -- Science:

The Neoproterozoic glaciations supposedly ended in a supergreenhouse environment, which led to rapid melting of the ice cover and precipitation of the so-called cap carbonates. If Earth was covered with ice, then extraterrestrial material would have accumulated on and within the ice and precipitated during rapid melting at the end of the glaciation. We found iridium (Ir) anomalies at the base of cap carbonates in three drill cores from the Eastern Congo craton. Our data confirm the presence of extended global Neoproterozoic glaciations and indicate that the duration of the Marinoan glacial episode was at least 3 million, and most likely 12 million, years.

This isn't evolution per se, though an easy case can be made that species changes 600-700 million years ago were the first tip off that something happened. This is a neat example of science at work. A hypothesis generates an unlikely prediction (a prediction unlikely to be true if the hypothesis is false, but likely to be true of the hypothesis is true). That prediction comes true, and the hypothesis itself is considered more likely.