【摘要】 根据中、美两国合作开展的西藏深反射地震结果,提出雅鲁藏布江缝合带（YZS）的"双陆内俯冲"构造模式和缝合带南、北分别存在着不同特征的、规模不一的部分熔融层；提出YZS处断裂向深部延深有限,认为YZS处地壳增厚有4种机制：①地壳规模的大的俯冲增厚；②上部地壳内的俯冲和背冲增厚；③下地壳内的底部垫托增厚和挤压增厚；④深部熔融体的向上挤入而引起的地壳增厚.提出可能存在两条大的伸展性断裂,造成江孜南、北地块间出现了大升降.更多还原

【Abstract】 The paper suggests a "Double Intracontinental Underthrusting Structure" modelwithin the Yarlung Zangbo Suture along with a deep architecture that there is a sepa-rate partial melting mass occurred 0n both southern and n0rthern sides of the suture,respectively, with their genetic origins being different one from another. The faultswithin the YZS have liAnted extensions t0 the depth’ Here altogether four mechanisms of crustal thickening are suggested: 1) a thickening due to crust-scaleunderthrusting; 2) a thjckening within the upper crust due to underthrustingand backthrusting; 3) a thickehing within the lower crust due to bottom uplifting from belowand compression; 4) a thickening due to an upward intrusion of deep molten mass. Itis, therefor, inferred that there is a likelihood of ekistence of two big extension faults,resulting in great elevation and subsidence.更多还原