Influences of Yixianian Volcanism on Sedimentary Environment in Sihetun Area, West Liaoning

Volcanic eruption facies and flooding facies are extensively developed in the Sihetun area,west Liaoning.Such voluminous and rapid volcanic activities in Phanerozoic have commonly been thought to be a cause for zoobio cenose extinction.The all uvial-fluvial,shore-shallow lacustrine,semi-deep and deep lacustrine facies were developed during volcanic dormancies,which provide evidence to study the influences of volcanism on sedimentary environment.The influences include: infilling of both volcanic and weat hering materials; burial and control by multiphased volcanic activities and upwar dchanges of volcanic-sedimentary facies associations; the Yixianian volcanic activities initiated crustal uplift and tectonot-opographic changes,which in turn affect draining modes; the biota experiencing volcanism influences can be evident for climate change.