VLF-EM FOLLOW UP OF THE EXPECTED SUBSURFACE OCCURRENCE OF SULPHIDE MINERALIZATION IN WADI ISBAIYA AREA, SOUTH SINAI, EGYPT

Document Type : Original Article

Authors

1 (1) Faculty of Science, Geology Department, Suez Canal University. Ismailia, Egypt.

2 (2) Faculty of Science, Geology Department, Portsaid University. Portsaid, Egypt.

Abstract

Ground geophysical survey, using the Very Low Frequency Electromagnetic method (VLF-EM), has
been conducted in Wadi Isbaiya area in order to investigate new occurrences of sulphide mineralization. The area is
situated on the outcropped basement plateau in the mid-southern Sinai, Egypt. Due to its rough terrain, almost no
previous ground geophysical surveys had been conducted at that location. Results from previous geological and
geophysical surveys, conducted at the easily accessible localities surrounding the area of study, delineated several
anomalies resulting from the presence of copper - sulphide mineralization and distributed in the quartz monzonite rock
units. The current study aims to trace the expected subsurface mineralization potentialities at the area of Wadi Isbaiya,
delineate their trends and extensions as well as deduce their structural relationship with other mineralization
occurrences found within its vicinities (ex: Umm Qeissum – Umm Alawi – Saint Catherine). The utilized VLF-EM
method enabled us to detect various conductive anomalies. Noticeable superimpositions between these different
anomalies were clearly observed at the central part of the study area, which asserts the existence of metallic
mineralization causative sources. Integrating the interpreted results of this VLF-EM survey allowed us to delineate the
lateral extensions of these causative mineralization sources and estimate their depths, which exceed 200m. Locations of
the intersection of the structural trends represent the most promising sites for metallic mineralization occurrences, and
were always accompanied by significant VLF-EM anomalies. Microscopic examinations and microprobe analysis
techniques confirmed the presence of anomalous sulphide mineralization, in the form of pyrite and chalcopyrite, in
addition to minor traces of gold and silver. These results may confirm the importance of structural factor, which may
control the occurrences of mineralization of economic value