Two episodes of volcanism in the Wudalianchi volcanic belt, NE China: Evidence for tectonic controls on volcanic activities

摘要

The NNW striking Wudalianchi Cenozoic volcanic belt (WVB) in NE China is mainly composed of volcanoes in Menlu River area, Keluo, Wudalianchi and Erkeshan. K-Ar radiometric dating suggests two episodes of volcanism in the WVB. Specifically, the Pliocene to early Pleistocene volcanism is distributed only in the northern part of WVB, whereas middle Pleistocene to Holocene volcanism occurred over the entire WVB. Geomorphological analyses further delineate four northeast-striking linear alignments of cones in the Wudalianchi and Keluo volcanic fields, probably related to magma feeding fractures with en echelon arrangement. No age progression is observed along these alignments. We propose that a NNW-trending rift may have controlled the eruption from Pliocene to early Pleistocene and a dextral transpression stress field may have influenced the volcanism from middle Pleistocene to Holocene. We suggest that the Pliocene and early Pleistocene volcanism is associated with far effect of the India-Eurasia collision, while the middle Pleistocene to Holocene volcanism in WVB may have resulted from interaction between the India-Eurasia collision and the subduction of the Pacific plate.