【摘要】 古岩溶洞穴中残留的次生方解石晶体可以作为裂变径迹测年的材料。通过测定遍及青藏高原的 2 0组洞穴次生方解石晶体的裂变径迹年代 ,结果表明 ,晚第三纪青藏高原的古岩溶过程和缓慢构造抬升过程相伴进行 ,其间在大约 10 Ma B.P.、12 Ma B.P.和 19Ma B.P.时洞穴次生化学沉积较为发育。由于地表切割程度的差异 ,晚第三纪岩溶过程在高原南部较为强烈 ,相对于第四纪期间的强烈抬升来说 ,高原晚第三纪的抬升速率较为缓慢 ,两者的差别达两个数量级。更多还原

【Abstract】 The recrystalline calcites in paleokarst caves may be used as fission trace dating material.We got 20 dates of recrystalline calcites in Tibet Plateau paleokarst caves with the method mentioned above,which indicated that the paleokarst process and the uplift process of the plateau happened at the same time in Neogene Period,and that the speleothems developed plentifully during three periods,i.e.around 10 0 MaB.P.,12 0MaB.P.,and 19 0 MaB.P.respectively.The Neogene paleokarst process was more intense in the southern part of the plateau than in the northern part,which was reflected by the difference of the degrees of landscape denudation.The uplift rate of the plateau was much slower in Neogene Period than in Quaternary Period,and the difference between them can be up to two orders of magnitude.更多还原