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Archean Butterstone By Clive Knell, Florence, SC
FormationDuring the Archean Period the surface of the earth formed, the oceans and the continents were established and life began in the shallow sea environment. There must have been seabed outcrops or lakes of considerable size which were turbid and muddy. This residue would over time have precipitated to the bottom in layers and early algael life would have settled within these banded layers of muddy residue. Around 2800 million years ago the atmospheric pressure was higher and heat production around 3 times present heat production, due to increased volcanic activity. This led to the serpentinization (green color) of the sediments that had by now become hard.
Micro FossilsMicro fossils in the form of Stromatolites of blue green algae have been found in the fine laminations and may represent the beginnings of life on earth and contain a history of our own origins. Micro fossils are microscopic relics preserved in rock by being incorporated into the sediment in such a way that they are not immediately broken down but are replaced in fine detail by the fossilization process. Stromatolites are structures in the laminated sedimentary rocks built by organisms such as algae or bacteria that have precipitated carbonates from the surrounding waters. Micro fossils in the form of fossilized algae are the earliest known life forms, predating the dinosaurs by 2500 million years, and represent the beginnings of life and fossils as we know them. Unlike conventional fossil collecting, the search for micro-organisms proves to be more difficult as Archean rocks do not give up their secrets easily. Identification of the microorganisms is difficult due to the lack of fine detail. There is, however, almost certain evidence of early life from about 2700 million years ago, with evidence of early life in southern Africa dated at about 3500 million years by Hamilton et al in 1979.
Whatever the controversy, it is a humbling experience to hold a piece of ancient history of such an incredible age in your hands, contemplate its formations and wonder at its origins.
This article may not be copied, distributed or reprinted in any form without the author's permission. To contact the author, please use the e-mail address provided. If you are unable to contact the author, please contact the Canadian Rockhound. Authorized reprints must acknowledge the author, original source and the Canadian Rockhound, and include the website URL address of the Canadian Rockhound. Document Number: CR9701306
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