Journal of Petroleum Geology, vol. 23 (3), July 2000, pp. 293-311.
Copyright
2000 by Scientific Press
Ltd. All rights reserved.
SILURIAN -- LOWER DEVONIAN BLACK SHALES IN MOROCCO:
WHICH ARE THE ORGANICALLY RICHEST HORIZONS?
S. Luning1*, D. K. Loydell2,
O. Sutcliffe3, A. Ait Salem4, E.
Zanella1, J. Craig1 and D. A. T.
Harper5
Lowermost Silurian (Rhuddanian, lower Llandovery) black shales represent the main
Palaeozoic petroleum source rock throughout North Africa and Arabia. The unit also occurs
in parts of Morocco with recorded TOC values of up to 10.5%. However, in contrast to many
other North African and Arabian countries, the Silurian-Lower Devonian shale-dominated
succession in Morocco also contains a number of other horizons with elevated organic
contents. In order to evaluate the organic richness and better understand the depositional
mechanisms of this shale succession in Morocco, samples were collected from petroleum
exploration wells, from the spoil heaps of shallow water wells and from outcrops, and were
subsequently analysed. Graptolite biostratigraphy provided a high-resolution correlation
framework. The data was integrated with that from published and unpublished studies, and
the results may help in improved predictions of the source quality of Silurian--Lower
Devonian strata in Morocco.