茅山新生代含幔源橄榄岩包体玄武岩与溧阳地震关系新探

笔者根据野外考察和测龄数据等发现,茅山及其邻区玄武岩有两次喷发旋回,形成早第三纪玄武岩和晚第三纪玄武岩.前者分布在茅东断裂带及其以东地区;后者分布在南京—溧阳断裂带上.两带交汇于竹箦王市和上沛老虎山,这两点恰好位于含幔源(橄榄岩)包体的橄榄玄武岩的所在地.它的存在不仅受特殊深部构造条件控制,而且后期构造变形明显.表明茅东断裂带与南京—溧阳断裂带已垂直延伸到上地幔,并且新三纪以后仍有活动.最后笔者从溧阳两次地震机制节面要素,震源体和余震分布与玄武岩分布图象关系等,推测含幔源橄榄岩包体的玄武岩可能是溧阳地震孕育和发生不可忽视的因素之一.

THE SEARCHING OF THE RELATIONS BETWEEN THE BASALT AND THE OCCURRENCE OF LIYANG EARTHQUAKES

The Besis of data for geological surveying and the geological age obtained by geochronological method,the authors have discovered that there are two erupting cycles of basalt in Maoshan and nearby regions.namely Eogene period and Neogene The former was widely distrubuted along the Eastern fault zone of Maoshan and in the East of it;the latter on Nanjlng-Liyang fault zone. Both zones are intersected at Wangsi and Laohushan,and the points of intersection just are in the field of basalt contained inclusion of olivine.It is a common knowledge that olivine is a mineral of the mantle so the both fault zones extended up to the mantle. Finally,the authors have discused the relations between the basalt erupting and the occurrence of Liyang earthquakes,and suggest that zone of Basalt eruption is a important reason for the occurrence of the Liyang earthquakes.