Glaciogenic and related sedimentary rocks: Main lithochemical features. Communication 1. Late Archean and Proterozoic

Lithochemical features of the Late Archean, Paleoproterozoic, and Neoproterozoic glaciogenic and related sedimentary rocks around the world are considered. Based on comparison with the average Post-Archean Australian Shale (PAAS), it is shown that the bulk chemical composition of diamictites reveals no specific lithochemical characteristics that would undoubtedly suggest their formation under cold climatic conditions. The chemical index of alteration (CIA) frequently applied in different paleoclimatic reconstructions should be considered as additional (though sufficiently important) tool, because its values for each analyzed object show significant variations mainly controlled by local factors.