西藏高原大地电磁深探测———亚东—巴木错沿线地区壳幔电性结构

摘 要　 展示了超宽频带大地电磁深探测所获得的西藏亚东—巴木错沿线地区电性结构图像; 阐述了西藏中、南部特殊的壳幔电性特征。     

Crustal Electrical Conductivity Structure of Southern Tibet from Magnetotelluric Survey

INTRODUCTIONAsatypicalintercontinent collisionarea ,Tibetanplateauisapresentlypopularregionnoticedbygeoscientistsallovertheworld ,sinceitisanidealandnaturallabforthestudyofthegeologicalevolutionoftheinnerlandmountain creatingzoneandoftheprocessofthecrust mantledeepdy namicsaswellasoftheinteractionbetweenthesurfaceandthecrustmovement.ThestudyoftheTibetanplateauevolutionisimportantnotonlyinsolvingsometheoreticalproblemsaboutcontinentaldynamicsandglobalchangesingeosciences ;butalsoinexplorin…     

雅鲁藏布缝合带硅岩的地球化学成因标志及其地质意义

通过西藏雅鲁藏布缝合带所产硅岩的化学组分中具有成因标志的不同元素组合比值（ＭｎＯ/ＴｉＯ_２、Ａｌ/（Ａｌ＋Ｆｅ＋Ｍｎ）及Ｆｅ/Ｔｉ-Ａｌ/（Ａｌ＋Ｆｅ＋Ｍｎ）的相关图解、Ａｌ-Ｆｅ-Ｍｎ的三角图和硅岩原子量进行对比研究，从一个侧面反映硅岩的成因及其雅鲁藏布缝合带形成和演化关系。     

雅鲁藏布江缝合带开合演化模式的探讨

通过对雅鲁藏布江缝合带的蛇绿岩、构造混杂岩的地质调查及其岩石化学、地球化学特征的分析,进一步证实了雅鲁藏布江缝合带萨嘎分岔的存在,探讨了雅鲁藏布江缝合带的演化模式。将雅鲁藏布江缝合带分为南、北两带,南带起始于二叠纪末期印度板块向北漂移过程中的伸展作用,到三叠纪末-早侏罗世,雅鲁藏布江缝合带南带伸展作用加剧,并伴有洋壳的裂陷和蛇绿岩的侵位,在较短暂的双向俯冲、碰撞后焊接了仲巴陆块。晚侏罗世到早白垩世之后,雅鲁藏布江缝合带北带再次扩张、俯冲,直到始新世晚期整个缝合带开始剧烈碰撞、造山、隆起,形成了雄伟的青藏高原。     

水岩作用对雅鲁藏布大拐弯北段滑坡的影响

通过对川藏公路南线八一至然乌段实地考察及对考察结果，已有资料的分析，本文运用统计学原理探讨了雅鲁藏布大拐弯北段地区滑坡与水岩作用的关系，并结合该地区发育的滑坡灾害具体分析了该地区水岩作用与滑坡的关系。经分析认为，该地区水岩作用条件复杂且利于发育各种典型的水岩作用，但地域性特殊的水岩作用形式更发育，并对雅鲁藏布地区滑坡灾害形成，诱发都有重要影响。     

Geomorphological problems of the middle reaches of the Tsangpo River,Tibet

The middle reaches of the Tsangpo River consist of alternating sections of wide valleys and gorges. The wide valley sections have braided and anastomosing channels, gentle hydraulic gradients, thick alluvial deposits and low terraces. In contrast, the gorge sections exhibit single, straight and deeply entrenched meandering channels with steep hydraulic gradients, bare rock river beds and higher terraces. Several hypotheses have been used to explain these unusual fluvial landforms, but geological, landform and sedimentary analyses along with dating information, suggest that the key could be the active faults across the river valley. All gorge sections are located on the upthrown side of active faults, which mainly occurred in or after the Pliocene, whilst the wide valley sections appear on the downthrown side. The faulting blocked the river and caused the formation of palaeolakes, with thick deposits laid down behind the faults. Therefore, depositional wide valleys were formed and old terraces were buried. On these downthrown sides of the faults, braided and anastomosing channels have developed. On the upthrown sides, strong incision of the river occurred because of the changes of the local base levels and river gradients. As a result, deep gorges and deeply entrenched meandering channels formed in various lithologies. The terraces on the gorge slope indicate different stages of river incision and the related knick points appeared close to the local active faults. Rock resistance is only a minor influence on the alternation of valley forms and river gradients in this area. © 1998 John Wiley & Sons, Ltd.     

雅江流域碎石层动力触探试验研究

结合雅江流域上数个大中型工程实践，较系统地研究了雅江流域上碎石层动力触探试验数据，结果表明该区域碎石层可采用动力触探进行原位测试，并可按相关的规定和规范进行修正击数、查取承载力和变形模量。     

雅鲁藏布大峡谷地区构造和地震活动特征

雅鲁藏布大峡谷地区位于喜马拉雅东构造结前锋地带,新构造运动和地震活动都十分强烈,两者关系密切。区内发育有北北东-北东向和北西西-北西向两组断裂构造,调查研究表明,它们的规模、性质、活动时代、活动强度等特征具有明显的差异：北西西-北西向断裂规模较大,多为逆冲、逆走滑断层,形成较早;北北东-北东向断裂单条规模相对不大,常集中分布,构成北北东向的剪切拉张断裂构造带,形成较晚,第四纪晚期活动明显。强震主要发生在喜马拉雅山差异运动强烈地带或地段,如块体周边的深大断裂带及其附近。7级以L地震主要与断裂构造带中规模较大、全新世强烈活动段、断裂几何构造复杂部位或多组方向断裂交汇密切相关。其中,7．5级以上地震发生在断裂构造带中走滑分量较大的北西向和北东向断裂带上。