Geological Society of America

32 Tectonics (Posters) I: New Discoveries in Global Tectonics

Sunday, 9 October 2011
9:00 AM - 6:00 PM
Hall C

PAN AFRICAN CLASTIC DEPOSITS IN TRIFYA BASIN, BOU AZZER, MOROCCO: STRATIGRAPHIC RELATIONS AND ORE POTENTIAL

Paper number: 32-8
Program: Technical Sessions
Time: 9:00 AM – 6:00 PM

Authors

Kevin Hefferan Presenting Author
University of Wisconsin-Stevens Point, Stevens Point, WI
Hassan Admou
Faculty of Sciences Semlalia, Cadi Ayyad University, Marrakech, N/A
S.D. Samson
Syracuse University, Syracuse, NY
Jeremy Inglis
University of North Carolina-Chapel Hill, Chapel Hill, NC
Ali Saquaque
Marrakech, N/A
Neil Heywood
University of Wisconsin-Stevens Point, Stevens Point, WI

Abstract

Age constraints on clastic sedimentary basins provide key details to late stage orogenesis and ore mineralization potential. The Trifya Basin is located in the Bou Azzer Inlier, Anti-Atlas Mountains of Morocco. This basin contains a coarsening upwards sequence of clastic rocks attributed to either: a) syn-orogenic Pan African deposits of the Latest Neoproterozoic Tiddiline Formation or b) post-orogenic deposits of the Early Cambrian Ouarzazate Formation. Recent field work (May, 2011) addresses the timing of basin deposits relative to the Pan African Orogeny, granodiorite intrusions and potential for gold-bearing deposits.

An angular unconformity observed in the southeast portion of the basin clearly distinguishes the steeply inclined Trifya deposits from the gently inclined, overlying rocks of the Ouarzazate Formation. Field mapping verifies that the Trifya basin deposits are syn-orogenic clastic rocks deposited in the late stages of the Pan African Orogeny. Granodiorite clasts in the Trifya Basin, originally interpreted to be derived from the 579 Ma Bleida Granodiorite intrusion, have been dated at 650 Ma. Based upon the age of these granodiorite clasts, it is likely that the Trifya Basin rocks are older than the Bleida Granodiorite.

As the Bleida Granodiorite intrusion distributed gold to host rocks north of the intrusion, the Trifya Basin deposits have potential as a gold prospect hosted in barite-calcite veins. At present we believe that the Trifya Basin contains Tiddiline Formation rocks ranging from 640-600 Ma. Ongoing U-Pb analysis of detrital zircons will provide tighter age constraints on clastic basin deposition and late stage Pan African deformation in Bou Azzer, Morocco.