Abstract

BAKKALI, Saad. ANALYSIS OF PHOSPHATE DEPOSIT "DISTURBANCES" USING THE HORIZONTAL-GRADIENT RESPONSES OF RESISTIVITY DATA (OULAD ABDOUN , MOROCCO ) . Earth Sci. Res. J. [online]. 2005, vol.9, n.2, pp.123-131. ISSN 1794-6190.

In the great Oulad Abdoun Basin exploitation of a new phosphate deposit was begun after the Grand Daoui horizon was exhausted. Inclusions of sterile hardpan-so-called "disturbances" -are hard to detect and interfere with phosphate extraction. Their resistivity is above 200 ?.m as against 80 to 150 ?.m for the phosphate-rich mineral. A Schlumberger resistivity survey over an area of 50 hectares was carried out. Models of the geology were successfully obtained from the analysis of the horizontal-gradient map of "disturbances". A new field procedure was tested to estimate the depth of disturbances. Phosphate reserves were better known.

Keywords : Geophysical surveys; resistivity; phosphate; horizontal-gradient; Morocco.

        · abstract in Spanish     · text in English     · English ( pdf )