abstract
- Glaciation cools the crust by setting its surface temperature to 0°C or well below. During the Cryogenian Snowball Earth glaciations, these conditions were in place long enough to cool the entire crustal column. Although crustal thermal history can be deciphered by thermochronology, these data are typically interpreted to record depth changes due to burial or erosion. Thermal models of the crust under Cryogenian boundary conditions predict that thermochronometers were substantially altered in the upper quarter to half of the crust. This Snowball Earth refrigeration, with little to no coeval erosion, may have imparted a cooling signal mimicking up to 3‒5 km of glacial erosion. Rock cooling previously attributed to massive Snowball erosion and linked to the Great Unconformity may instead reflect a great refrigeration of Earth's crust, with implications for thermochronology across other climate events.