金沙江支流硕曲河中更新世红土层的发现及地质意义

    Discovery of Pleistocene laterite bed in the Shuoqu branch of Jinshajiang River and its geological significance

    • 摘要: 金沙江支流硕曲河V级及以上阶地阶面和两级带状剥夷面上发现中更新世红土层。根据ESR、14C测年资料,结合地层层位、冰期和深海氧同位素阶段对比,将红土层形成时代确定为150~185ka,与康滇地区中更新世末期网纹化红土可以对比。拟建为吾斯顶红土层。红土层形成于海拔2000m以下湿热的河流宽谷环境,现今海拔为2890m以上,因此该区中更新世末期以来处于平均速率为5.9mm/a的快速隆升状态,气候与环境向着日趋恶化的方向演化

       

      Abstract: The middle pleistocene laterite bed was discovered on the surface of terraceⅤor above and on the belting denudation plane of terraceⅡ. According to the data of ESR and the 14 C isotope age as well as the result of the correlation of stratigraphy, ice period and deep sea oxygen isotope, the age of the laterite is 150~185 ka, which makes it possible to correlate it with the late Pleistocene reticulate laterite of Sichuan Yunnan regionally.The middle pleistocene laterite bed will be named as Wusiding laterite bed, formed in hot and humid environment of a wide valley, with an altitude of no more than 2,000 m above sea level. Now the altitude is more than 2,890 m, so the areas have been uplifting rapidly since the late Pleistocene,with an average speed of 5.9 mm/a, which makes the hot and humid air weaken, and climate and environment tend to become worse and worse.

       

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