Geochronology and geochemistry of Cretaceous–Eocene granites, Tengchong Block (SW China): Petrogenesis and implications for Mesozoic-Cenozoic tectonic evolution of Eastern Tethys

•The Early Cretaceous granitoids in TCB may form in an arc-continent collisional setting.•The Late Cretaceous Paleocene granitoids form in TCB BSB syn-collision to post-collision setting.•The Early Eocene granitoids form in subduction of the Neo-Tethyan Putao Myitkyian oceanic crust, and collision between WBB and TCB.•It is the multi-stage subductions and collisions that are responsible for both zonation of the granites and mineralization diversity inTCB. [Display omitted] The Early Cretaceous–Early Eocene granitoids in the Tengchong Block record the evolutionary history of the Mesozoic-Cenozoic tectono-magmatic evolution of Eastern Tethys. (a) The Early Cretaceous granitoids with relatively low (87Sr/86Sr)i ratios of 0.7090–0.7169 and εNd(t) values of −9.8 to −7.8 display metaluminous, calc-alkaline dominated by I-type granite affinity and hybrid mantle–crust geochemical signatures. They may have been derived from melting of the subducted Meso-Tethyan Bangong-Nujiang oceanic crust with terrigenous sediments in an arc-continent collisional setting. (b) The Late Cretaceous–Paleocene granitoids with relatively high (87Sr/86Sr)i ratios of 0.7109–0.7627, and εNd(t) values of −12.1 to −7.9 exhibit metaluminous to peraluminous, calc-alkaline dominated by S-type granite affinity and hybrid Lower–Upper crust geochemical signatures, which may be originated from partial melting of the Meso-Proterozoic continental crust in the collision setting between the Tengchong Block and Baoshan Block. (c) The Early Eocene granitoids have metaluminous, calc-alkaline I-type and S-type granites dual affinity, with relatively high (87Sr/86Sr)i ratios of 0.711–0.736, εNd(t) values of −9.4 to −4.7, showing crust-mantle mixing geochemical signatures. They may have been originated from partial melting of the late Meso-Proterozoic upper crustal components mixed with some upper mantle material during the ascent process of mantle magma caused by the subduction of the Neo-Tethyan Putao–Myitkyian oceanic crust, and collision between the Western Burma Block and the Tengchong Block. It is these multi-stage subductions and collisions that caused the spatial and temporal distribution of the granitic rocks in the Tengchong Block.