Marinoan Snowball Glaciation Archives

Idealized ice growth and stratigraphy at onset of snowball Earth. Note vertical exaggeration.

Atmospheres, Climate, Weather, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Cryobiology, Habitable Zones, Icy Worlds, Mapping, Geodesy, Cartography, Bathymetry, Status Report, Water/Hycean Worlds & Oceanography

Four-million-year Marinoan Snowball Shows Multiple Routes To Deglaciation

by Keith CowingApril 22, 2025April 22, 2025

Twice during the Neoproterozoic Era, Earth experienced runaway ice-albedo catastrophes that resulted in multimillion year, low-latitude glaciations: the Sturtian and Marinoan snowball Earths.

Model benchmark against the modern climate system. Histograms show the results for observable variables from 1000 model runs where uncertain parameters are sampled. The vertical shaded regions are the measured or assumed modern values. (a, b, c) We assume the pre-industrial modern climate had 280 ppm atmospheric CO2, 285 K surface temperature, and 8.2 ocean pH. (d) The calcite and aragonite saturation states of the modern ocean vary from over 5 at the surface to below 0.5 in the deep ocean (Pilson 2012). (e) Estimates of continental carbonate weathering are from Hartmann et al. (2009), continental silicate weathering are from Moon et al. (2014), and seafloor weathering are from Coogan & Gillis (2013) and Krissansen-Totton et al. (2018). (f) Estimates of neritic carbonate deposition are from Iglesias-Rodriguez et al. (2002) and pore-space deposition are from Gillis & Coogan (2011) and Krissansen-Totton et al. (2018). -- astro-ph.EP

Astrogeology, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Cryobiology, Gaia - Planetary Perspectives, Habitable Zones, Icy Worlds, Status Report, Water/Hycean Worlds & Oceanography

Three-stage Formation of Cap Carbonates after Marinoan Snowball Glaciation Consistent with Depositional Timescales and Geochemistry

by Keith CowingAugust 20, 2024

At least two global “Snowball Earth” glaciations occurred during the Neoproterozoic Era (1000-538.8 million years ago). Post-glacial surface environments during this time are recorded in cap carbonates: layers of limestone […]