Skarn-mineralized porphyry adakites in the Harlik arc at Kalatage, E. Tianshan (NW China): Slab melting in the Devonian-early Carboniferous in the southern Central Asian Orogenic Belt

Petrogenesis of rhyolite at Kalatage in the Eastern Tianshan, Northwest China: Evidences from geochemistry, zircon U–Pb geochronology, and Hf isotopes

“…Previous studies were focused on revealing the tectonic evolution from Late Ordovician to Permian in this district and followed as (a) in the Late Ordovician, the Kangguer Ocean slab that was subducted northward beneath the Dananhu island arc to form the Yudai porphyry Cu (Au, Mo) mineralization in the Kalatage district (Y. Sun et al, ); (b) in the early Carboniferous (334–322 Ma), more subducted oceanic crust melted in the North Tianshan suprasubduction zone, generating a considerable volume of arc‐related volcanic rocks and granitic intrusions in the Harlik–Dananhu arc (Mao et al, ); (c) in the early Permian, oblique subduction in the southern Altaids gave rise to strike‐slip extensional faults, which controlled the emplacement of large volumes of mantle‐derived melts to form the Shaerhu alkaline complex (age of 286 Ma) in the Kalatage area, and the Early Permian Shaerhu alkaline complex was generated in a suprasubduction zone setting (Mao, Xiao, et al, ); and (d) in the Middle Permian, the bimodal (basic–acidic) volcanic rocks of the Aerbashayi Formation were emplaced in extensional and/or rift settings (Zhu et al, ). From the above discussion, it is showed that the Upper Carboniferous rocks were poorly understood in the Kalatage area.…”

“…The Ordovician–Carboniferous Harlik–Dananhu arc is located between the Kelameili Palaeozoic suture and the late Carboniferous Kanggur suture zone, and it consists of calc‐alkaline mafic–felsic lavas, volcaniclastic tuffs, and flysch sediments (Ma, Shu, & Sun, ; Mao, Xiao, et al, ; Xiao et al, ). The arc‐related granitic intrusions with an age of Ordovician to Permian, is especially abundant in the Harlik area (F. W. Chen et al, ; G. H. Sun, Li, Gao, & Yang, ; Guo, Zhong, & Li, ; H. Q. Li et al, ; Hou, Tang, Liu, & Wang, ; Mao et al, ; Mao et al, ).…”

“…It is mainly composed of slightly metamorphosed Palaeozoic mafic to felsic volcanic, volcaniclastic, and sedimentary rocks and is intruded by the Ordovician to Permian granitoids (Figure ; Mao, Xiao, et al, ). Outwards from the Kalatage anticlinal hinge, the rocks are divided into five formations: (a) the Lower Devonian Dananhu Formation consists of biogenic carbonates, clastic sediments, and interbedded volcanic rocks; (b) the Upper Carboniferous Qishan Formation consists of calc‐alkaline basaltic and andesitic lavas, tuffs, and clastic sediments; (c) the mid‐Permian Aerbashayi Formation is composed of basalts and basaltic andesites interbedded with minor rhyolites (lower sequence), and tuffs, rhyolites, and dacites (upper sequence); (d) the Upper Permian Kula Formation consists of clastic sediments; and (e) the Lower Jurassic Sangonghe Formation contains black shales, shaly sandstones, sandstones, and coal beds and lies unconformably on all older strata (Mao et al, ).…”

“…The belt can be geographically divided into the western and eastern segments. The Eastern Tianshan belt occupies a critical tectonic activity position of the southern segment of the CAOB, and it was formed by amalgamation and accretion of continental margin arcs, island arcs, ophiolites, accretionary wedges, turbidites, and overlap sequences situated between the southern active margin of the Siberian Craton to the north and the Tarim Craton to the south from the Ordovician to Early Permian (Mao et al, ; Mao et al, ; Mao, Fang, Wang, Wang, & Wang, ; Mao, Wang, et al, ; Mao, Xiao, et al, ).…”

“…The Kalatage area is located in the middle of the Harlik–Dananhu arc in the Eastern Tianshan belt, and the Ordovician–Jurassic volcanic, volcaniclastic rocks, and clastic sediments lithologies are widespread in this district (Mao et al, ). From Late Ordovician to Early Carboniferous, the North Tianshan ocean subducted northward beneath the Harlik–Dananhu island arc (Mao et al, ; Y. Sun et al, ).…”