Mineral Exploration and Environmental Impact in Halla Area in The Northern Part of The Masafi-Ismah Metamorphic Window, U.A.E. the MASAFI-ISMAH metamorphic window, U.A.E.

The Masafi-Ismah Metamorphic Window is an approximately triangular-shaped area of sub-greenschist to locally upper amphibolite facies metamorphic rocks, which widens from a narrow point at its southern termination near the town of Masafi, northwards to the southern boundary of the Dibba Zone. It contains polydeformed metasedimentary and meta-igneous rocks that structurally underlie the mantle succession of the Khor Fakkan block of the Oman-UAE ophiolite along a contact interpreted as a sole thrust (Searle and Graham, 1982; Lippard et al., 1986; Searle, 1985; Robertson et al., 1990; Searle and Cox, 2002). The study area is located in the northern part of the Masafi-Ismah metamorphic window in a series of folded volcanics and cherts referred to as the Tayibbah Metavolcanic Formation. The aim of exploration is to find useful mineral deposits and appraise their suitability for further investigation and, where appropriate, assess the environmental impact of radioactive or other hazardous minerals in the study area. The study area has many occurrences of carbonatites, which are found as dikes, sills, and veins. They are usually associated with continental rift-related tectonic settings, however, in the study area they have an oceanic setting. The studied carbonatite rocks are fine to coarse-grained, and consist of magmatic silicate and carbonate material. Twenty-three samples were collect from the study area. The geochemical data indicate high values of metals usually found in important economic ore minerals of elements Th, U, La, Mn, Ag, Zn, Sr and traces of gold. The geochemical data also include a number of detectable thorium and uranium values. In excess, the radioactive isotopes of these elements could have negative effects on the quality of the soils and groundwater in the region, depending on the mobility and dispersion of these elements in the near surface. The rock geochemical data lean towards acceptable levels for thorium and normal levels for uranium, however, soil chemical and hydrogeochemical surveys, especially in the areas of mineralization, warrant further investigation.