龙泉山西麓晚第四纪以来的沉积及构造意义

Sedimentary and Tectonic Significance since Late Quaternary in the Western Piedmont of Longquan Mountain

龙泉山西麓山前晚第四纪沉积发现两套不同类型的粘土沉积,这为研究沉积和构造的关系提供了载体。通过详细的野外地质调查、粒度和钻孔分析,结果表明:成都粘土在龙泉山西麓主要分布在洛带以北的地区,形成于晚更新世晚期,属于近源的风成沉积。柏合粘土在龙泉山西麓主要分布在洛带和太平镇之间,物源来自于龙泉山,属于静水环境条件下的沉积。龙泉山西麓第四纪沉积物形成时代及厚度的变化反映了来自于龙门山的挤压力是持续的和非均匀性的,其潜在的地震风险性应引起足够的重视。

Two different types of late Quaternary clay deposition were found in the west piedmont of Longquan mountain,which provided a carrier for the study relationship between sedimentary and tectonic. Through detailed field geological investigation,grain size analysis and geochronology test,the results show that: the chengdu clay is mainly distributed in foothill belt,formed in the late pleistocene,mainly for the proximal late Quaternary of aeolian clay deposit;Bohezhen clay is mainly distributed between Baihe and taiping town,provenance from the longquan mountain,belong to the static water under the conditions of the sedimentary environment. The formation age and thickness of quaternary sediment in western piedmont Longquan Mountain reflect that the extrusion pressure of longmen moutain is constant and heterogeneity,it should be sufficient attention by the potential seismic risk.