The sedimentary environment and source of ore-forming materials of sandstone-type copper deposits in southeast Kuqa Basin, Xinjiang, China

A series of sandstone-type copper deposits and occurrences are distributed in the Kuqa Basin, Xinjiang. Based on field surveys, authors researched the sedimentary environment and metallogenic model of copper deposits southeast of the basin. The relationship between the sedimentary environment/facies in the area and the copper mineralization was summarized to explore the genesis of mineralization and the metallogenic model. We identified main sedimentary facies types of alluvial fans, fan deltas, and lakes in the Neogene strata, and further identification of five subfacies and seven microfacies was made. Our research results reveal that the genesis of sandstone-type copper mineralization is related to the sedimentary environment, and the mineralized bodies are mainly distributed in fan delta plain facies and fan delta front facies. Detrital zircon dating results of two samples from Kangcun area are 427.4 ± 6.6 Ma, 387.3 ± 3.3 Ma and 424.6 ± 2.3 Ma, 279.9 ± 6.8 Ma.The other two samples from Duwanke area are 285.6 ± 3.0 Ma, 449.5 ± 3.2 Ma and 427.5 ± 2.3 Ma. It indicates that the source of the copper-bearing sandy conglomerate in the Miocene Jidike Formation (N1j) is mainly from the strata and magmatic rock products formed by the geological evolution during the Late Silurian to Early Permian.