Helicopter EM (ZTEM–VTEM) survey results over the Nuqrah copper–lead–zinc–gold SEDEX massive sulphide deposit in the Western Arabian Shield, Kingdom of Saudi Arabia
Jean M. Legault 1 3 Carlos Izarra 1 Alexander Prikhodko 1 Shengkai Zhao 1 Emad M. Saadawi 21 Geotech Ltd, 245 Industrial Parkway North, Aurora, Ontario, Canada L0R2H3.
2 MA’ADEN, 24th Floor, King Road Tower, PO Box 13784, Jeddah, Kingdom of Saudi Arabia 21414.
3 Corresponding author. Email: jean@geotech.ca
Exploration Geophysics 46(1) 36-48 https://doi.org/10.1071/EG14028
Submitted: 14 March 2014 Accepted: 21 August 2014 Published: 27 October 2014
Abstract
Magnetic and electromagnetic (EM) results from two helicopter EM surveys, a time-domain (VTEM) and AFMAG (ZTEM), are compared over the Nuqrah sedimentary exhalative (SEDEX) massive sulphide deposits in the Western Arabian Shield of the Kingdom of Saudi Arabia. The magnetic and EM data from both surveys map the major controlling structures that host the Nuqrah North and South deposits. Neither Nuqrah deposits stand out as distinctive aeromagnetic anomalies, but both EM surveys define the massive sulphide mineralised vent and bedded portions of the SEDEX orebodies. ZTEM is interpreted to be more capable in defining the larger, lower conductance and less mineralised distal portions of the SEDEX system. The modelled ZTEM also defines a down-dip extension of the Nuqrah South zone below a depth of 750 m.
Key words: AFMAG, airborne, electromagnetic, magnetic, SEDEX, VTEM, ZTEM.
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