摘要
对芙蓉洞与芙蓉江古水面高程差进行了测量,引用洞穴古老次生化学沉积物同位素地质年代资料,通过和邻区地壳相对抬升速率对比,估算出芙蓉洞洞穴演化形成所需的历史时间约为12～18万a。相对于芙蓉洞古老次生化学沉积物同位素地质年龄(16万a)来说,洞穴演化形成是一个不可忽视的过程,进一步证明了两个清晰的洞穴发育阶段的存在。对于用洞穴古老次生化学沉积物同位素地质年龄代替洞穴发育整个历史过程是需要谨慎的。通过估算方法反演所揭示的该区地壳相对抬升速率与青藏高原相对抬升速率相比,进一步证实了扬子地台和青藏高原虽然具有相同的驱动机制,但扬子地台近代隆升速率远远低于青藏高原的隆升速度。同时,笔者还对扬子地台的隆升趋势作了一定的分析,认为近代扬子地台边缘隆升速度小,中间隆升速度稍大。
The historical time for Furong cave to evolve and form is estimated by the meterage of the height of Furong cave and ancient water surface of Furong river. With the help of neighbouring area＇s uplift rate and isotope age of speleothems in Furong cave, which is approximately 120~ 180 ka. This means the process for Furong cave to evolve and form is not neglectable compared with the needed time （160ka） for speleothems to form and proves obviously the two stages exist during the cave＇s evolution. It must be cautious to substitute the whole historical process of the formation of Furong cave with the isotope age of speleothems. The inverse uplift rate of this area confirmed ulteriorly Yangtze platform and Qinghai-Tibet plateau have the same driving mechanism but with different velocity, and the former is highly faster than the latter. At the same time, the uplift trend of Yangtze platform is analysed and it is reckoned that the margin is characterized by a slower velocity but the interior by a higher one.
出处
《西北地质》
CAS
CSCD
2005年第4期1-7,共7页
Northwestern Geology
基金
国家自然科学基金重点项目(批准号:90202017)
