A Neoproterozoic Snowball Earth

• DOI: 10.1126/science.281.5381.1342
• Publication Date: 2002-07-27T09:43:20Z
• Authors: Paul F. Hoffman; Alan J. Kaufman; Galen P. Halverson; Daniel P. Schrag
• Keywords: Snowball Earth; Subaerial

Negative carbon isotope anomalies in carbonate rocks bracketing Neoproterozoic glacial deposits Namibia, combined with estimates of thermal subsidence history, suggest that biological productivity the surface ocean collapsed for millions years. This collapse can be explained by a global glaciation (that is, snowball Earth), which ended abruptly when subaerial volcanic outgassing raised atmospheric dioxide to about 350 times modern level. The rapid termination would have resulted warming Earth extreme greenhouse conditions. transfer result precipitation calcium warm waters, producing cap observed globally.