江孜地区第四系阶地地质特征及地球化学特征  

Geological and Geochemical Characteristics of Quaternary Terrace in Jiangzi Area

作　　者：何龙[1] 马运超 王一伟[1] HE Long;MA Yunchao;WANG Yiwei(Northwest Sichuan Geological Team,BGEEMRSP,Mianyang Sichuan 621000)

机构地区：[1]四川省地质矿产勘查开发局川西北地质队,四川绵阳621000

出　　处：《四川地质学报》2023年第3期395-398,共4页Acta Geologica Sichuan

摘　　要：江孜地区大面积分布第四系阶地,本次研究在江热乡新发现有残留第四系Ⅳ级阶地。本次研究获得了第四系不同阶地ESR年龄,其中Ⅳ级阶地形成时间为160±16 ka,为中更新世晚期沉积;Ⅲ级阶地形成时间为117±11 ka,为晚更新世早期期沉积;Ⅱ级阶地形成时间为41±4 ka,为晚更新世早期期沉积;Ⅰ级阶地形成时间为16±1 ka,为晚更新世早期期沉积。阶地黏土主量元素及微量元素含量变化不大,具有高TiO2/Al2O3,低K2O/Al2O3的特点;稀土分量值也变化不大,轻稀土富集的平坦-微右倾型,无明显Eu异常。阶地黏土物源来自于较远的地方,经历了长距离搬运和充分混合作用,且风力作用较弱,主要以流水搬运为主,黏土堆积时的温度与现代温度大致相同。Quaternary terraces are widely distributed in Jiangzi area.In this study,the new residual Quaternary class IV terraceswere found in Jiangre village.In this study,the age of ESR isotope ages in different Quaternary terraces was obtained,and the formation time of terraceⅣwas 160±16 ka,which was the late Middle Pleistocene sediments.The formation time of classⅢterrace is 117±11ka,which is the early late Pleistocene sediments.The formation time of class II terrace is 41±4 ka,which is the early Late Pleistocenesediments.The formation time of Class I terrace is 16±1ka,which is the early late Pleistocene sediments.The content changeof major elements and trace elements of the clay from the terrace clay wassmall.It is characterized by high TiO2/Al2O3 and low K2O/Al2O3.The rare earth content change was also small,enriched inLight Rare Earth,with no obvious Eu anomaly.The origin of the terrace clay sourced from a distant place,experienced long distance transport and full mixing,and the wind effect was weak,mainly carried by water.The clay accumulation temperature was roughly the same as the modern temperature.

关 键 词：第四系 阶地 地质特征 地球化学特征 

分 类 号：P56[天文地球—构造地质学]