Original paper
Proposal of formal lithostratigraphical units for the Terminal Proterozoic to early Middle Cambrian of southern Morocco
Geyer, Gerd
Newsletters on Stratigraphy Volume 22 Number 2-3 (1990), p. 87 - 109
28 references
published: Jul 2, 1990
ArtNo. ESP026002202008, Price: 29.00 €
Abstract
Lithostratigraphic units for Terminal Proterozoic to lowermost Middle Cambrian strata of the Anti-Atlas and High Atlas mountains are formally erected, based mainly on traditional units of CHOUBERT and those of SIEGERT (1986). Additional descriptions characterize briefly the lithostratigraphic units and its depositional environments. The lithological succession of the Anti-Atlas is divided (from bottom to top) into the Taroudannt Group, composed of Adoudou Formation (subdividable into a Basal Member and a Limestone Member) and Lie de vin Formation, and the Tata Group, composed of Igoudine Formation (with the Tiout Member), Amouslek Formation, Lemdad Formation, Tislit Formation, Issafen Formation, Jbel Tichinchine Formation, Asrir Formation, Aguerd Formation, Tazlaft Formation, and Akerouz Formation, respectively. Both groups represent complex cyclothems reflecting developments from transgressive to regressive depositional and environmental conditions. Above the Asrir Formation the Bréche à Micmacca Member can locally be distinguished at the base of the Jbel Wawrmast Formation. The "Lower shale formation of the inner Feijas" is renamed into Tamanart Formation, the "Upper shale formation of the inner Feijas" into Akka Formation.
Kurzfassung
Die bisher schlecht begründeten und ungenügend abgegrenzten lithostratigraphischen Einheiten vom obersten Proterozoikum bis zum untersten Mittelkambrium im Anti-Atlas und Hohen Atlas werden formal errichtet. Sie basieren hauptsächlich auf von CHOUBERT und SIEGERT (1986) eingeführten Einheiten. Beschreibungen charakterisieren kurz die lithostratigraphischen Einheiten und ihr jeweiliges Ablagerungsmilieu.