The oil shales of Timahdit (Morocco) constitute an important resource in en
ergy. Indeed, the total organic matter is mainly constituted by kerogen. Th
e elementary analysis gives atomic ratios H/C and O/C that are characterist
ic of a type II kerogen, poorly evolved, constituent of a good mother-rock.
The different constituents separated from extractible organic matter by co
lumn or thin layer chromatography have been characterized. The analysis of
saturated and aromatic hydrocarbons by gas chromatography has proved that t
he organic matter of the shales of Timahdit is immature, resulting essentia
lly from a phytoplanctonic biomass (marine origin) with a small continental
influence. These results have been confirmed by the spectroscopic study of
vanadyl and nickel petroporphyrins (DPEP and Etio) isolated from the organ
ic matter of the Timahdit shales. (C) 2001 Academie des sciences/Editions s
cientifiques et medicales Elsevier SAS.