Clay Mineralogical Evidence of Early Oligocene-Early Miocene Aridification on the Northeast Margin of the Tibetan Plateau： A Case Study of Lanzhou Basin

详细信息   

• 责任者：Liang Guojun (Faculty of Earth Sciences ; China University of Geosciences ; Wuhan 430074 ; China) ; Hong Hanlie
• 刊名：Acta Petrologica et Mineralogica
• 出版年：2012
• 卷期：31(3)
• 关键词：渐新世 ; Oligocene ; 中新世 ; Miocene ; 粘土矿物 ; clay minerals ; 青藏高原 ; Qinghai-Tibetan Plateau
• 页码：p.432-440
• 图表：4 illus., 48 refs.
• 分类号：1200
• issnNo：ISSN1000-6524
• isbnNo：CN11-1966/P

摘要

    

///To reveal palaeoclimatic evolution and aridification events of Early Oligocene-Early Miocene period on the northeast margin of Tibetan Plateau, the authors investigated micro-morphology, relative content of clay minerals and V（Ill＋Chl）/V（Sme） ratios of sediments in Lanzhou Basin by means of X-ray diffraction（XRD） and scanning electron microscopy（SEM）. SEM results indicate that clay minerals were apparently corroded in the relatively warm and humid period and presented distinctly physical weathering characteristics in the relatively arid period. The aridification events probably resulted from the multi-stage uplifts of Tibetan Plateau.