一、地质概况 安徽滁县中生代火山岩盆地为长江中下游一系列火山岩盆地之一,它位于张八岭隆起的东侧,受平行于郯庐断裂的次级断裂控制,形成北北东向的断陷盆地。盆地基岩较老,西部直接覆盖在震旦亚界灯影组之上,其分布受古地形的制约(图1),南部、东部不整合在早古生界地层之上。 火山岩系可分为三个韵律,即以火山角砾岩或角砾凝灰岩开始,以熔岩结束。晚期有 I. Geological Survey The Mesozoic volcanic basin of Chu County in Anhui Province is one of a series of volcanic basins in the middle and lower reaches of the Yangtze River. It is located on the east side of the Zhangbaling Uplift and is controlled by the secondary faults parallel to the Tanlu Fault, forming a north-north-trending faulted basin . The bedrock is older, with the western part directly covering the Sinian sub-group Dengdeng, whose distribution is controlled by the paleo-topography (Fig. 1). The southern and eastern parts are unconformable above the Early Paleozoic strata. Volcanic rocks can be divided into three rhythms, that is, volcanic breccia or breccia tuff, beginning with lava. Late there