The role of transregional mantle-rooted structural discontinuities in the concentration of metals: With examples from the United States, China, Uzbekistan, Burma, and other countries

Abstract

Transregional EW-trending mantle-rooted structural discontinuities play an important role in the concentration of metals in the northern hemisphere. Preferential concentration of metals occurs in areas where these discontinuities intersect with major structures of other trends. Previous studies focused mainly on the United States and China (Kutina, 1980b, 1983b, 1991, 1995 and 1999) are extended by the investigation of metal concentrations along westward extension of two latitudinal belts of China into neighboring parts of Asia: The transregional structural discontinuity which controls the Yinshan-Tianshan latitudinal belt of northern China and its western extension has been traced, presently, as far west as the Aral Sea region, for a distance of over 5,000 km. In western Uzbekistan the large concentrations of gold and other metals in the Central Kyzylkum Desert, including the superlarge gold deposit of Muruntau, originated at the intersection of the latitudinal belt mentioned above with a NW-trending foldbelt which is associated with the Southern Tian Shan Mountains. A major structural intersection has been defined in northern Burma at a latitude close to 24° N based on the position of seismically active fracture zones and a change in the orientation of the Wadati-Benioff Zone (using data from the seismotectonic study by Vanek et al., 1990). This intersection occurs at the latitude of a major fault of the Nanling latitudinal belt of southern China which extends towards the Burmese border and apparently continues westward. A correlation can also be seen with the latitude of the Dauki Fault in the adjoining parts of the Indian Peninsula. The position of the structural intersection mentioned above, between the major latitudinal belt of southern China and the Dauki Fault of Indian Peninsula, indicates that an old EW-trending structural discontinuity may have played a structural role in the tectonics of the younger plate interaction. The postulated structural intersection in northern Burma occurs in the Wuntho-Katha area where a volcanic belt and granitoid rocks are known as well as deposits of different metals including Zn, Cu, Au, Te, and Pt (Goossens & Myint Hla, 1977). Also, a low-temperature colloform sphalerite has been described from this area, which is characterized by the same association of typochemical elements (Ge-Tl-As) as sphalerites of the large European deposits near the German-Belgian border and in Poland (Kutina, 1969b). This area is considered to be a promising target for mineral exploration. Examples are also shown from the Czech Republic, Canada, and Australia.