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Sediments of the Precambrian Wadi Abu Barqa Formation influenced by life and their relation to the Cambrian sandstones in southern Jordan

by Klaus Bandel, Hamburg & Rafie Shinaq, Irbid

 

BANDEL, K. & SHINAQ, R. (2003): Sediments of the Precambrian Wadi Abu Barqa Formation influenced by life and their relation to the Cambrian sandstones in southern Jordan. Freiberger Forschungshefte C 499: Paläontologie, Stratigraphie, Fazies (11): 78-91; Freiberg.

Abstract

Sediments exposed at Wadi Abu Barqa in southwestern Jordan have formed at the late Precambrian in the proximity of volcanoes. The tuffaceous sediments have been overprinted by cyanaobacterial mats which stabilized sediment surface under the cover of shallow water and within the wet zone of exposition. Wadi Abu Barqa Formation is characterized as a sedimentary sequence, covering the crystalline base and being covered by volcanic deposits. The deposition began with stromatolites encrusting the crystalline base. The relation to the underlying crystalline base and overlying Precambrian deposits as well as to the Saramuj Formation at Ghor Safi further to the north is discussed. A model for the location and time of formation of Wadi Abu Barqa Formation is presented. The Cambrian sandstones covered the Precambrian series after weak metamorphisation, deformation and the erosion of large portions (more than 100 m) of the series took place. The relation of Wadi Abu Barqa Formation to the Saramuj Formation is not resolved, but, in contrast to published models the latter may be younger than the former. Cambrian sandstones at the Wadi Abu Barqa region of Jordan covered a rugged landscape with aeolian sand at first, which afterwards (end of early Cambrian) was inundated by the sea. This marine pipe rock is correlated with the late lower Cambrian and early middle Cambrian deposits exposed near the Dead Sea.