Australia: The Land Where Time Began

A biography of the Australian continent 

Northwestern Australia and East Africa A Deglaciation Event in the Early Permian between these 2 Landmasses

Along the entire length of the Tethyan margin of Gondwana the base of the Gondwana megasequence is formed by glacigene deposits from the late Palaeozoic. The prevailing climate largely controlled the lithology of the deposits in these sequences and the climate influence was also imposed on early diagenesis*. A change from a mineralogically immature composition (arkosic chloritic) of the periglacial sediments to a mature, kaolinite pyrite quartz dominated lithofacies of the periglacial deposits  reflects the change from the cold glacial climate to a postglacial environment that was cool temperate. The appearance of black, kaolinitic lutites, that usually have high organic carbon content, is a typical feature of the latter period. In this paper only a few examples of typical deglaciation sequences, of the many known occurrences, are discussed, including Tanzania, Southern Oman, the Lesser Himalaya, northwestern Australia and southwest China. These deglaciation sequences have been shown by microflora and fauna that all these deglaciation sequences are from the Late Asselian to Early Sakmarian age indicates that along the Tethyan margin of Gondwana deglaciation was a synchronous event, within the limit of dating methods. In the Late Sakmarian/Early Artinskian a peak in sea level was experienced in all but 1 of the sections that have been described here, which supports this statement. The sudden increase of bioproduction that was stimulated by higher temperatures and a high atmospheric carbon dioxide concentration caused the high level of organic matter content in the deglaciation deposits. The dominance of euxinic conditions during this period was a high organic material, combined with basin geometries that were overdeepened. According to Wopfner the rapid, synchronous amelioration of climate cannot be explained by the shifting of pole positions, rather, only by global warming that was rapid and sustained.

*https://en.wikipedia.org/wiki/Diagenesis

Sources & Further reading

  1. Wopfner, H. (1999). "The early Permian deglaciation event between East Africa and northwestern Australia." Journal of African Earth Sciences 29(1): 77-90.

 

Author: M. H. Monroe
Email:  admin@austhrutime.com
Last updated:
24/11/2015
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                                                                                           Author: M.H.Monroe  Email: admin@austhrutime.com     Sources & Further reading