The Tekka tin deposit, Perak, Peninsular Malaysia

This paper is concerned, primarily, with the nature and genesis of the multi­ mineralic veins at Tekka, Perak, Peninsular Malaysia. The rock types in the area include marble, schist and granite. The granite emplacement and resulting tensional fractures, that trend approximately E-Wand dip northwards, provided passage­ ways for ascending mineralising agents, and the veins and adjacent country rocks became the sites of deposition of an impressive number of mineral species. The genesis of these mineralised bodies was complex and involved at least three phases of mineralisation that were separated by periods of renewed fracturing. From a mineralogical and temporal point of view the veins can be classified into three main types:- (a) An early quartz-tourmaline type with or without cassiterite, wolframite, arsenopyrite and minor amounts of other sulphide-bearing species. (b) A second (later) type consisting of quartz with or without cassiterite, wolframite, arsenopyrite and minor amounts of other sulphide-bearing minerals. (c) A third, and still later, type consisting of quartz, stannite, other sulphides and sulpho-salts, with or without cassiterite and arsenopyrite. The common non-metallic gangue minerals present are quartz, tourmaline, topaz, sericite, muscovite and fluorite, and, in addition, a number of supergene secondary products which includes varlamoffite. Wall-rock alteration adjacent to the veins includes silicification, tourmalinisation, greisenisation and kaolinisation. The deposit is best classified as xenothermal because of the telescoping of high-temperature mineral species such as cassiterite, columbite/tantalite and wolframite which are closely associated with ones believed to be low-temperature minerals, such as galena and stibnite.