Glaciations Neoproterozoic

Bodiselitsch B, Koeberl C, Master S, Reimold WU (2005) Estimating duration and intensity of Neoproterozoic snowball glaciations from Ir anomalies. Science 308 239-242... 

It seems strange, therefore, that the Late Neoproterozoic should have been a time of severe glaciations (Kirschvink, 1992). In their review of the snowball Earth hypothesis, Hoffman and Schrag (2002) point out that in some sections a steep decline in values by 10-15% ... 

It seems very likely that the continents were largely ice covered during the Neoproterozoic glaciations. The state of the oceans is still a matter of debate. The Hoffman-Schrag Snowball Earth... 

Leather J., AUen P. A., Brasier M. D., and Cozzi A. (2002) Neoproterozoic snowball Earth under scrutiny evidence from the Fig glaciation of Oman. Geology 30, 891—894. 

Figure 8 Archean distribution of banded iron formations, with short reoccurrence associated with widespread glaciation in the Neoproterozoic, and the Proterozoic and Phanerozoic distribution of sedimentary rocks containing ferric-iron cements (red beds). The end of banded iron formation and beginning of red bed deposition at —2.2 Ga has been taken as evidence for a major oxygenation event in Earth s atmosphere.

The first episode of Neoproterozoic glaciation (Sturtian, c.760-700Ma) accompanied the opening of the Pacific Ocean, while the second (Varangerian or... 

Fig. 6.17 Carbonate isotopic excursions during Neoproterozoic glaciations predicted by the Snowball Earth and gas-hydrate models (after Jacobsen 2001). Zero on the time scale corresponds to onset of cap-carbonate deposition.

The Neoproterozoic interval witnessed supercontinent formation and breakup and profound global-scale glaciations that persisted for perhaps millions of years (Knoll 1991). It therefore is not surprising that this interval experienced substantial isotopic excursions reminiscent of those during the Paleoproterozoic (Fig. 10). Eukaryotic lineages that would lead directly to plants and animals had developed by this time. It is generally believed that the events associated with tectonics, climate and the biogeochemical cycles played important roles in the enormous diversification of plant and animal life at the dawn of the Phanerozoic Eon. 

G.M., and Selby, D. (2004) Constraints on the timing of Marinoan Snowball Earth glaciation by Re-187-Os-187 dating of a Neoproterozoic, post-glacial black shale in Western Canada. Earth Planet. Set. Lett., 222 (3—4), 729—740. 

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