The discovery and preliminary assessment of stratabound\ud barium-zinc mineralisation in Dalradian metamorphic rocks\ud near Aberfeldy (outlined in MRP Report No. 26) resulted\ud from co-ordinated geological, geochemical, geophysical and\ud mineralogical studies, full details of which are presented\ud here. The presence of an extensive zone of mineralisation\ud in the area was recognised initially by a geochemical\ud drainage survey and , reconnaissance geological mapping.\ud Subsequently, more detailed mapping and drainage sampling\ud were supplemented by VLF-EM geophysical surveys, overburden\ud and rock sampling, and shallow drilling. The\ud VLF-EM technique successfully delineated resistive rocks\ud within the generally conductive graphitic schists and proved\ud a valuable mapping aid in areas of poor exposure.\ud The mineralised zone is defined by the presence of\ud bedded baryte, sulphide concentrations, quartz-celsian rock\ud and micaceous schists in which the muscovite is barium-rich.\ud It varies in thickness from about 60 m to 110 m and\ud extends, at least intermittently, over 7 km of strike and\ud through a vertical interval of 370 m. Individual baryte bands\ud are 2.3-l 5.5 m thick and may extend along strike for up to\ud 1.8 km. The greatest sulphide concentration is in carbonate\ud rock assaying 8.5% Zn and 3.6% Pb over 4.3 m. Other\ud unusual constituents of the mineralised zone are the barium\ud silicates hyalophane and cymrite and the chromian muscovite\ud fuchsite.\ud It is concluded that the mineralisation is of synsedimentary\ud origin, involving the introduction of metal-rich\ud hydrothermal brine into an euxinic basin
To submit an update or takedown request for this paper, please submit an Update/Correction/Removal Request.