缅甸兰里岛泥火山灾害与成因机制探讨

MUD VOLCANO DISASTER AND GENETIC MECHANISM IN RAMREE ISLAND

文中主要探讨缅甸兰里岛泥火山灾害与成因机制,结合兰里岛地质背景以及泥火山活动现状,对在兰里岛东北部、中部以及西部所取3个泥火山采样点的样品进行粒度分析以及显微形貌分析,发现样品粒度在1～100μm之间,均呈单峰正态分布,粒径中值相近,粒度分布集中,分选较差,粒度对称程度呈很正偏态;样品基质以泥质为主含有大量泥质碎屑、细小晶体碎屑以及少量气孔,并含有少量蚀变强烈的斜长石晶屑和辉石晶屑,可判定样品点物源相同。据此推断兰里岛普遍存在均匀泥质层作为泥火山喷发的统一物源。

This paper mainly discusses the mud volcano disaster and its genetic mechanism in Ramree Island.Combined with the geological background of Ramree Island and the present situation of the mud volcano,grading analysis and micro-morphology analysis have been made by taking samples from three sampling sites of the northeast,the middle and the western part of Ramree Island.The finding is that the particle sizes of samples between 1～100μm show a unimodel normal distribution,with similar grain size mid-value,concentrated size distribution,poor sorting,and quite positive skewness in grading symmetry;The samples＇ matrix are mainly argillaceous,containing a lot of argillaceous clasts,tiny crystal clasts and a few pores,and having a little strongly altered plagioclase phenocryst and pyroxene phenocryst,from which,we can judge that the sampling sites have the same provenance.Thus,it can be deduced that there is a uniform argillaceous layer as the unified provenance of the Ramree Island mud volcano.