The identification of Mesozoic Pacific plate subduction: Evidence from paleomagnetism of the Late Triassic bedded cherts in Raohe area, eastern Heilongjiang Province

Abstract: The bedded cherts in Raohe area of eastern Heilongjiang Province constitute a significant component of Mesozoic Wandashan orogenic ophiolitic melange. A new paleomagnetic investigation was carried out for a Triassic red chert sequence in the western part of the WOB, with totally 200 samples collected. The bedded cherts of Lower Triassic Dajiahe Formation in Wandashan Orogenic Belt (WOB) in eastern Heilongjiang Province have been partially or completely subjected to remagnetization. In combination with the data of tectonic evolution of Wandashan Orogenic Belt and micropaleontology, the authors hold that the time of remagnetization was Late Jurassic-Early Cretaceous, caused by the orogenic fluid related to the westward subduction of the Pacific Plate.