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对QA-I剖面中新世黄土-古土壤序列的石英颗粒进行扫描电镜观察和粒度测试,并与第四纪典型黄土样品进行了对比.QA-I剖面石英颗粒以次棱角状和棱角状为主,与第四纪黄土一致;粒度以小于50μm的粉砂级组分占绝对优势,最大粒径小于120μm,进一步支持QA-I剖面为典型风尘沉积.古土壤层的石英和全岩粒度均小于黄土层,指示它是加积型古土壤,具有季风环境下土壤的典型特征.本研究为中新世黄土的成因和形成过程提供了新的沉积学证据.
The QA-I section of the Miocene loess-paleosol sequence was examined by scanning electron microscopy and particle size tests and compared with the typical Quaternary loess samples. The QA-I quartz particles were characterized by sub-angular and angular The main, consistent with the Quaternary loess; Particle size less than 50μm of silt-level components accounted for the absolute advantage, the largest particle size of less than 120μm, further support the QA-I section is a typical dust deposition. Paleosol layer and the whole rock particle size Less than the loess layer, indicating that it is an accretionary paleosol with typical characteristics of soils in the monsoon environment. This study provides new sedimentary evidences for the genesis and formation process of the Miocene loess.