摘要
通过对比研究青藏高原东缘若尔盖-泸定地区低温年代学样品(ZFT样31件、AFT样56件和A(U-Th)/He样37件)各参数(隆升年龄和隆升速率)特征表明,该地区中生代以来的抬升冷却过程具由北向南的递进隆升特征,南部丹巴弧形带与北部茂县弧形带产生了显著的隆升剥露"翘掀式"调整,北部弧形带隆升剥露较早、速率先快后慢,南部弧形带隆升剥露较晚、速率先慢后快;且在早中新世研究区处于平静期,抬升剥露作用显著减缓。年龄及抬升冷却速率等值线垂向上浅部(70℃等温面)较深部(110℃等温面)弧形展布特征显著;平面上总体向南具连续弧形变化趋势(年龄变新、隆升速率增大)。抬升冷却(剥露)特征显示出中央造山带和青藏高原的形成对该地区隆升过程的强烈影响,以及弧形构造格架对浅部地表抬升剥露的显著控制作用。
The uplift or denudation is shown as a progressive process from north to south in the eastern margin area of the Tibetan Plateau during the Meso-Cenozoic by the low-temperature thermochronological data （31 ZFT samples, 56 AFT samples and 37 A（ U-Th）/He samples）. The uplift rates are remarkably different between the Danba Arc Belt and the Maowen Are Belt. The Maowen Arc Belt was uplifted earlier than the Danba Arc Belt,and its rate of uplift and denudation was firstly high（110Ma） but became lower later（10Ma）. The Danba Arc Belt was uplifted later. Its rate of uplift and denudation decreased remarkably in the Early Miocene and kept stable for a period. But it uplifted and denudated much faster after Early Miocene. It is indicated that the age of uplift（ or rate of denudation）gradually became older（ or lower）from the South to the North or from SE to NW in the region,which has the typical character of arc framework in shallow layer（70~C isoclines）. Therefore,the process of uplift in the eastern margin area of the Tibetan Plateau is strongly influenced by the formation and evolution of Central Orogenic Belt and Tibetan Plateau, and has been intensively controlled by the arc framework in shallow layer.
出处
《第四纪研究》
CAS
CSCD
北大核心
2009年第3期574-585,共12页
Quaternary Sciences
基金
国家自然科学基金项目
中国石油化工股份有限公司联合基金项目(批准号:40739907)资助
关键词
低温年代学
隆升作用
弧形格局
青藏高原东缘
low-temperature thermochronology, progressive uplift, are framework, eastern margin of Tibetan Plateau
