强震诱发大型岩质滑坡的滑面中岩石角砾的高温胶结作用  

Rock cementing phenomenon on the sliding bed of Sunjiayuan rock avalanche triggered by Whenchuan earthquake

作　　者：李祥龙[1] 唐辉明[1] 

机构地区：[1]中国地质大学工程学院,湖北武汉430074

出　　处：《煤田地质与勘探》2011年第6期48-53,共6页Coal Geology & Exploration

基　　金：中国地质调查局项目(1212010914036)

摘　　要：汶川特大地震在北川县陈家坝乡地区诱发了许多地质灾害,其中孙家园滑坡后壁出露有一种特殊的红褐色岩石壳体,形态如岩石熔化重新胶结一般,甚至具有比基岩还要高的强度。根据对孙家园滑坡后壁所出露的红褐色壳体的形态特征、出露条件和其矿物成分的鉴定,建立了一种新的岩型——滑面角砾岩。通过对滑带角砾快速胶结成岩机理的分析,并结合孙家园滑坡的特点,证明了在强震作用和特殊的地质条件下,滑带岩石角砾可以满足产生快速铁质胶结所需要的温度条件,而且这个温度远低于岩石矿物熔化所需温度。Whenchuan earthquake triggered many geo-hazards in Chenjiaba in Beichuan area, and Sunjiayuan rockslide was one of the biggest ones In the rockslide back-wall a special russet rock shell was revealed, which had strength higher than that of the underlying bed rock. A new definition named sliding-surface breccia was brought according to the characteristics and mineral identification of this special rock shell. By analyzing the mechanism of fast rock granular cementation, it is proved that under the severe earthquake and certain specific geological and topographical conditions, the temperature in the sliding zone can rise to meet the required temperature under which rock particles in the sliding zone can be conglomerated by ferruginous cementation. In addition, this temperature is far lower than the mineral melting temperature of rocks.

关 键 词：地震诱发岩质滑坡 滑面角砾岩 滑带高温 岩石胶结 

分 类 号：P642.22[天文地球—工程地质学]