【摘要】 西藏门巴地区发育多级层状地貌,即不同高度的山顶面、盆地面与多级河谷阶地地貌。深入研究这些层状地貌的特征、成因和形成时代,是探讨青藏高原隆升年代、幅度和过程的重要途径。对该区层状地貌的研究表明:门巴地区不同高度的山顶面是渐新世晚期形成的老夷平面在高原持续隆升过程中解体后的残留;不同规模和方向的盆地地貌面是高原隆升过程中伸展作用的产物。研究区广泛分布的多级阶地表明0.15 Ma(共和运动)以来该区又进入了强烈的隆升时期。更多还原

【Abstract】 The Menba area in central Qinghai-Tibet Plateau formed several types of step-like landforms,which are composed of the stepped mountaintops at different altitudes,flattened basin floors and multi-stepped fluvial terraces.The detailed study on their features,forming mechanisms and ages of these different stepped landforms is one of the important paths to probe into ages,processes and ranges of the uplifting at Qinghai-Tibet Plateau.The study shows that the landform of stepped mountaintops at different altitudes in the Menba area is a kind of monadnocks that old planation formed in late Oligocene dismembered during the consistent uplifting of the plateau;the flattened basin floors with different scales and directions are the products resulted from stretching during the uplifting of the plateau.The widely distributed multi-stepped fluvial terraces indicate that the Menba area has experienced several strongly uprising movements since ca.0.15 Ma("Gonghe"tectonic movement).更多还原