Results of a geochemical survey, Aban Al Ahmar Quadrangle, Sheet 25F, Kingdom of Saudi Arabia

Abstract

The interpretation of geochemical data from a regional survey of the Aban al Ahmar quadrangle resulted in the selection of areas for follow-up studies. The results of detailed geochemical studies of these areas, combined with field observation, resulted in the selection of areas of moderate to high mineral resource potential. The most important areas are (1) the Jibal Minyah area, Aban al Asmar area, Jibal Suwaj area, and Nubayah area where tin and tungsten mineralization are associated with Abanat-suite rocks or possible buried Abanat-suite plutons; (2) several areas containing rocks of the Murdama group in the northern part of the quadrangle, the Buqaya al Luaah area, and the Jabal Akkash area where precious-and base-metal mineralization are generally associated with small Idah-suite plutons; and (3) the southern periphery of Jibal Qitan associated with skarn mineralization.. The Aban al Ahmar quadrangle (sheet 25F) lies in the northeastern part of the Proterozoic Arabian Shield. Plots showing the distribution of single elements and factor scores of the regional geochemical data for wadi concentrates were used to select favorable areas for follow-up work. Detailed follow-up studies consisted of the collection of samples of rocks, wadi concentrates, and wadi sediments. The most useful pathfinder elements for precious-and base-metal mineralization are Cu and Pb, and for tin and tungsten mineralization they are Sn, La, Nb, Y, and Be. R-mode factor analysis of the regional geochemical data resulted in two factors that reflect mineralization: precious-and base-metal mineralization; and Abanat-suite lithology and, therefore, tin and tungsten mineralization.A major problem in the interpretation of the regional geochemical data resulted from incomplete removal of magnetite from the samples prior to analysis. The presence of magnetite can cause anomalous values of Ni, Fe, V, Cu, and Co in samples because of it's ability to incorporate these elements into its structure during magmatic crystallization.

A proposed new Precambrian skarn deposits in the Arabian shield

“…The integration between magnetic, remote sensing, and the published geochemical data give the following conclusions: Skarn deposit locations in the Arabian shield (AS) from (Ahmed, 2002;Ahmed and Hariri, 2006;Hummel and Ankary, 1972;Lemiere et al, 1990;Miller and Arnold, 1988;Moufti, 2013;Nehlig et al, 1999;Surour and Moufti, 2011;Williams, 1984). Overall, the arc-related skarns are oxidized except for Al Madhiq.…”

“…Jibal Qitan and An Nimriyah South are reduced skarns in the Murdama basin that were induced by the Idah suite (Fig. 2; Table S1) and are dominated by Sn -W mineralization (Miller and Arnold, 1988). However, the Al Khushaymiyah complex is an oxidized causative magmas, and this complex is the causative magma for the Kirsh oxidized skarn (Table S1).…”

“…Other localities for the arc-related successions that host skarn deposits include Al Amar, Hamra, As Safra, Bi'r Ash Shumt, and Jabalul Hamat (Table S1). Jibal Qitan garnetiferous skarn is located at the contact between Qitan granite and the Murdama group limestone (Miller and Arnold, 1988). Sn -W mineralization is dominant in Qitan skarn, and there's a possibility for potential mineralization in the subsurface at the contact between granite and the Murdama limestone (Miller and Arnold, 1988).…”

“…Jibal Qitan garnetiferous skarn is located at the contact between Qitan granite and the Murdama group limestone (Miller and Arnold, 1988). Sn -W mineralization is dominant in Qitan skarn, and there's a possibility for potential mineralization in the subsurface at the contact between granite and the Murdama limestone (Miller and Arnold, 1988). There are different types of post-Murdama granites, so there's a higher possibility for the skarn deposits at the contact between these intrusions and the Murdama limestone.…”