Geological structure and copper mineralization of the Tekturmas ophiolite belt and related structures of central Kazakhstan

Abstract

The article presents an overview of the main stages of magmatism and ore mineralization of copper and other metals of the Tekturmas ophiolite belt and related structures of Central Kazakhstan. The age, composition and probable tectonic settings during the formation of Cu-Ni deposits in Central Kazakhstan associated with sulfide mineralization are discussed. The Tekturmas ophiolite belt includes formations of three lithological types: basaltic Karamurun and Kuzek formations, siliceous Tekturmas and Bazarbai formations and clastic Sarytau, Airtau and Yermek formations. The potential ore mineralization of the Tekturmas ophiolite belt is associated with plutonic mafic and ultramafic rocks of the ophiolite section, within the Karamurun and Kuzek formations of the Tekturmas and Bazarbai segments, respectively. The Uspenka rift zone, which is adjacent to the Tekturmas ophiolite belt, includes three volcanogenic-sedimentary associations of Early-Middle Silurian, Early-Middle Devonian and Late Devonian-Early Carboniferous ages. The Uspenska copper deposit is related to the youngest Late Devonian-Early Carboniferous association. The geological structure of the territory, which includes magmatic bodies with Cu-Ni ore mineralization, should serve as a basis for an integrated approach to studying oreforming systems. The most promising locations of copper mineralization within the Tekturmas ophiolite belt and Uspenska rift zone are the Kamkor and Uspenska-Bella deposits and the Urtynjal, Ordobasy and Shopa ore occurrences. All these deposits are associated with mafic and ultramafic intrusive complexes. The main regional and local geological characteristics of these deposits and ore occurrences, along with the types of ore mineralization, are discussed. It is argued that Central Kazakhstan has limited prospects for the discovery of large Cu deposits; however, the discovery of medium-size and small-size deposits of that type is quite possible. The discovery of new large Cu-porphyry deposit in the Tekturmas ophiolite belt is also unlikely; however, additional prospecting works aimed at identification of new ore bodies in the vicinity of already known deposits and ore occurrences presents research interest.