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Dating quaternary sediments

Clays also dominate sediments of the topmost (0–3 m) zone with illite as the dominant (74–81%) specie followed by smectite suggesting derivation from the mixed metamorphic and igneous terrain of Aravallis.

Quaternary, in the geologic history of Earth, a unit of time within the Cenozoic Era, beginning 2,588,000 years ago and continuing to the present day.

The grain-size distribution of this zone closely matched with the sediments underlying the modern Sabarmati riverbed at Ahmedabad, suggesting fluvial depositional environment.However, no decision was made to equate the beginning of the Pleistocene Epoch to the beginning of the Quaternary Period, and indeed the very status of the Quaternary as a period within the geologic time scale had come into question.Various gatherings of the IGC in the 19th and 20th centuries had agreed to retain both the Tertiary and Quaternary as useful time units, particularly for climatic- and continent-based studies, but a growing number of geologists came to favour dividing the Cenozoic Era into two other periods, the Paleogene and the Neogene.These variations in turn have driven rapid changes in life-forms, both flora and fauna.Beginning some 200,000 years ago, they were responsible for the rise of modern humans.The clay content in the middle zone (3–18 m), dominantly sandy, is very low.Therefore, provenance for this zone was derived using heavy minerals in the sand fraction.Land close to the glaciers and affected by the cold temperatures (periglacial landscapes) were areas of permafrost and tundra.Farther away, vast dry, cold grasslands (steppes) were formed.The type section for the The most distinctive changes seen during the Quaternary were the advances of ice into temperate latitudes of the Northern Hemisphere.The glacial landscapes were dominated by ice several kilometres thick that covered all but the highest peaks in the interior.

Comments Dating quaternary sediments