鄂西黄陵穹隆新生代隆升特征及其环境效应

位于湖北省西缘的黄陵穹隆具有基底加盖层双层结构，其暴露的基底主要以黄陵花岗岩为代表。该穹隆对长江三峡的形成演化、四川－江汉盆地一带构造格局的形成，以及三峡大坝的安全性等方面均具有重要控制和影响作用。本文通过对黄陵花岗岩的裂变径迹特征分析，结合野外实测阶地地貌数据，获得了黄陵穹隆65Ma以来的隆升速率、隆升高度和剥蚀速率等方面的数据：1)65-7Ma，隆升速率为24.6-7.4m/Ma，隆升高度为1426.8-429.2m；2)7Ma至今，平均隆升速率为204.1m/Ma，隆升高度为1428.7m。而0.73-0.01Ma以来隆升速率由0.058m/Ka增加为1.033m/Ka，平均隆升速率为0.134m/Ka，显示出早期隆升较慢，后期加快的趋势。65Ma以来，至少总的剥蚀厚度为2455.5m-1457.9m，其中7Ma以来剥蚀的厚度为1028.7m，剥蚀速率为0.147mm/a。研究结果约束了长江三峡的形成时间和过程，证实了三峡是一年轻的河谷。

Cenozoic uplift characteristic and environment effect of Huangling Dome in the west of Hubei Province

Huangling Dome is constitutive of base and cover rocks, which is located in the west edge of Hubei Province, and Hungling Granite is the representative outcrop of the base. Huangling Dome is very important to the formation and evolution of the Yangtze Three Gorges, the formation of structural pattern of Sichan-Jianghan Basins, and also has important effect on security of Yangtze Three Dam. Based on fission track analysis of Hungling Granite, combining with research of terrace characteristic in field, we obtain data of uplift velocity, uplift height and denudation velocity of Huangling Dome since 65Ma: 1)65-7Ma, uplift velocity was 24.6-7.4m/Ma, and uplift height was 1426.8-429.2m; 2)7-0Ma, uplift velocity was 204.1m/Ma, and uplift height was 1428.7m. Especially, uplift velocity increased from 0.058m/Ka to 1.033m/Ka in the course of 0.73Ma to 0.01Ma and mean velocity was 0.134m/Ka, which showed that uplift velocity was slow in the early stage , but increased continuously from then on. Total denudation depth was 2455.5m-1457.9m since 65Ma, and denudation depth was 1028.7m and mean denudation velocity was 0.147mm/a from 7Ma to present. Research results restrict formation time and process of the Yangtze Three Gorges, and prove the Three Gorges is a youthy river valley.