dbo:abstract
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- The Whitehill Formation, alternatively written as White Hill Formation and formerly known as White Band or Whitehill or White Hill Member, is a regional Early Permian (Artinskian to Kungurian, dating to around 282 to 275 Ma) geologic formation belonging to the Ecca Group in the southeastern ǁKaras Region of southeastern Namibia and Eastern, Northern and Western Cape provinces of South Africa. The formation comprises black shales, mudstones, siltstones, dolomite beds, gypsum and halite layers and a layer of tuff within the formation. With a thickness between 50 and 70 metres (160 and 230 ft) and present in an area of 600 by 600 kilometres (370 by 370 mi), the formation is considered the primary target for shale gas potential in the Southern Karoo. Total Organic Carbon (TOC) values average 4.5% with a range from 0.5 to 14.7%, placing the formation in the same range as the well-known Barnett Shale and Marcellus Formation of the United States. The Whitehill Formation of the Karoo and is contemporaneous with the Huab Formation of the and is correlated with a series of formations in the Pelotas and Paraná Basins in southeastern Brazil, deposited in a larger basinal area, 150 million years before the break-up of Pangea. The abundance of Glossopteris and Mesosaurus fossils are characteristic of the Gondwanan correlation across present-day South America, Africa, Antarctica and Australia. The Whitehill Formation has provided fossil reptiles, insects, fish and flora. (en)
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