TY  - JOUR
TI  - Anomalous enrichment of redox-sensitive trace elements in the marine black shales from the Duwi Formation, Egypt: Evidence for the late Cretaceous Tethys anoxia
SP  - 7
N1  - cited By 32
AV  - none
EP  - 14
PB  - Elsevier Ltd
SN  - 1464343X
ID  - scholars8432
KW  - anoxia; black shale; Cretaceous; depositional environment; redox conditions; remineralization; Tethys; trace element
KW  -  Egypt
N2  - Marine black shale beds in the Duwi Formation of NE Egypt are part of the Late Cretaceous-Palaeogene Middle East-North African phosphogenic province. These black shales were analyzed for their redox-sensitive trace elements (V, Ni, Mo, U, Cu, Cr, Re, Cd, Sb, Tl, and Mn) to examine their depositional conditions. The data show that the black shales have elevated concentrations of redox-sensitive trace metals, low Mn contents, low Th/U and V/Mo ratios, and high V/Ni, Ni/Co, V/(V + Ni) and V/(V + Cr) ratios as well as a positive correlation of metal Mo to V concentrations. These geochemical data suggest that the Campanian-Maastrichtian Tethys was stratified and stagnant, with reducing bottom water conditions. The high V/Ni ratios in the study shales indicate their dominantly marine origin and suggest that the high-productivity upwelling system that persisted over �20 m.y. at the southern margins of the Tethys Ocean is the main source of the organic matter. A combination of elevated primary productivity, remineralization and reducing depositional conditions is the main control of enrichment of redox-sensitive trace elements in the black shales of the Duwi Formation. © 2017
VL  - 133
A1  - Baioumy, H.
A1  - Lehmann, B.
JF  - Journal of African Earth Sciences
UR  - https://www.scopus.com/inward/record.uri?eid=2-s2.0-85019167790&doi=10.1016%2fj.jafrearsci.2017.05.006&partnerID=40&md5=4dab24e11d8c5b87ce2969bf7e982c78
Y1  - 2017///
ER  -