Accretionary orogenesis triggered by collision across continent distance: Evidence from the Proto‐Tethyan West Kunlun, China

Abstract

AbstractProto‐Tethyan orogenic processes prior to the late Ordovician collision remain unclear. Both whole‐rock La/Yb‐ and zircon Eu/Eu*‐based crustal thickness proxies along with petrological and geological observations were used to reconstruct mountain‐building history for the West Kunlun orogenic belt, China, over the span of Early Palaeozoic. Here, we demonstrate that Proto‐Tethyan West Kunlun crust has observed significant accretionary orogeneses at 520–480 Ma and 480–450 Ma and collisional orogenesis at 450–400 Ma. The 520–480 Ma accretionary orogenesis in West Kunlun together with the coeval Delamerian accretionary contractional orogenesis in eastern Australia were simultaneously induced by continent‐continent collisions that welded the Gondwana landmass. Ca. 440 Ma docking of Tarim and its eastern neighbouring blocks along the northern margin of Gondwana in turn triggered the Lachlan accretionary orogenesis along the opposite margin. This study highlights that accretionary orogenesis could be a manifestation of far‐field compressional stress from continent‐continent collision.