俯冲

In this paper, we mainly use plate subduction model to calculate and simulate some major subduction boundaries all over the world, and discuss the problem of the dip angle.

文中主要通过平板俯冲模型来计算模拟全球范围内一些大的俯冲边界，并对俯冲角等问题作了一些讨论。

The age of adakitic dacite is about 514.2±8.5 Ma, and the age of eclogite from the northern margin of Qaidam basin is 494.6±6.5 Ma. Therefore, it is considered that the slab started its subduction in Late Cambrian, that the adakitic magma was formed at the subduction depth of about 75~85 km, and that the partial melting residues with garnet facies continued subducting and finally formed eclogite in Early Ordovician.

据其地球化学研究结果并结合该区埃达克质英安岩(5 14.2± 8.5Ma)和榴辉岩(494.6± 6 。5Ma)的年龄数据，推测柴北缘板片在晚寒武世开始俯冲，俯冲板片在 75～ 85km深处开始部分熔融形成埃达克质岩浆，而熔融残留部分继续俯冲，在早奥陶世形成含石榴石残留相的榴辉岩。

The evolution process under the control of the multigeodynamic force system (including the boundary forces of Eurasia-Pacific-Indian three massive plates around Nansha block, effects of the deep mantle, relative soft layer-sliding planes within Nansha lithosphere block and the earth's rotational inertial force) can be briefly divided four stages: the late Cretaceous to the early Eocene stage of uprilfing-erosion and shear-extension caused by the oceanwards-eastwards withdrew of Pacific subduction zone and the delamination of proto-subducted slab after the stage of pre-Cretaceous pre-rifting active continentoceanic plate margin. In this stage, the Nansha transcrustal layering-block started to move southeastwards on the Nansha transcrustal layer-sliding plane, meanwhile, the Andu-Bisheng and Liyue-Banyue basement layering-block slid on their upper-crust layer-sliding planes, and Xibu accretion zone was formed. Successively, it entered the stage of the mid-Eocene to early Oligocene, when NW-SE sea-floor spreading occurred in the southwest subbasin owing to the slip-line field initiated by the collision between the Indian and Eurasian plates, Zengmu foreland-basin started to develop in the same time. And in the stage of late Oligocene to early Miocene, near NS simple-shear extension and sea-floor spreading in the central subbasin of eastern South China Sea resulted from the south-southeastwards drawing-force of the mantle-flow. The crustal layering-blocks and the Miri accretion zone formed also in this stage.

南沙岩石圈新生代微板块及板内层块构造的动力演化过程，在多元动力等因素(如块体之外的欧-太-印三大板块运动边界力和地幔深部活动因素、块体内部软弱层滑面以及地球自转变化)控制下，大致经历了4个阶段的演化：从前晚白垩世的裂前活动陆-洋板块边缘阶段因太平洋俯冲带向东跃迁、原向NNW俯冲消亡的板片的拆沉、幔隆而进入晚白垩世-早始新世的隆升剥蚀、剪切伸展演化阶段，南沙超壳层块顺超壳层滑面祥东南运移、安渡-毕生与礼乐-半月基底层块沿上壳层滑面拆离，西布增生带形成；继而先后在中始新世-早渐新世期间受印-欧板块碰撞滑线场、地球自转加速影响出现西南海盆NW-SE向海底扩张和曾母前陆盆地的发育，和晚渐新世-早中新世期间南—东南向地幔流牵引造成的中央次海盆近NS向单剪伸展与海底扩张、壳体层块向南差异滑移、米里增生带形成；中中新世以来，印度-澳洲板块快速向北俯冲，构成今日南海格局。

With a dip angle between 15° and 30°, the uplift of an obducted plate during continental collision is much higher, and able to form a high mountain. The uplift is greatest with a dip angle of 15°; whereas with a dip angle between 30° and 45°, the subduction depth of a plate is much deeper, and able to form a deep basin. The subduction depth is greatest with a dip angle of 45°. When the dip angle is equal to or greater than 75°, subduction and obduction movements between two continents become undistinguishable.

当断裂带倾角在15~30°时，两个大陆板块碰撞导致的仰冲板块一侧隆升高度相对更大，利于形成高大的山脉，其中以15°倾角对应的仰冲板块一侧隆升最高；当断裂带倾角在30~45°时，两个大陆板块碰撞导致的俯冲板块的俯冲深度相对更深，利于形成深陷的盆地，其中以45°倾角对应的俯冲陆块一侧俯冲最深；当断裂带倾角≥75°时，两个大陆板块之间的相对俯冲和仰冲作用变得不明显。

According to the variation in the components of intermediateacid igneous rocks coming from the lower crust, it is possible to restrain the depth of the source area and the minimum thickness of the crust, and thus to provide important information for the study of the deep process of the continental intraplate mineralizationGlobally, many world level porphyry copper deposits and metallogenic systems formed by hypabyssal hot liquid have their close relationship with the synchronous adakite in spacetime and genesis; domestically, the adakitelike rocks have been identified to be related to the metallogenesis in the main metallogenic areas in ChinaThe recognition of adakitelike rocks having no relationship with the process of subduction makes it possible to construct a metallogenic model of continental intraplate porphyry metal deposits by combining other geological evidences, and this model is totally different from the metallogenic model of porphyry copper deposits with Bsubduction setting constructed by Sillitoe (1972)The existence of adakitelike rocks may be the necessary condition but not the sufficient one for forming the largescale porphyry deposits and the hypabyssal hotliquid deposits, whose metallogenic elements mainly came from the mantleThe metallogenic potential of adakitelike rocks is achieved by the entering of the mantle material, and the metallogenic specialization of adakitelike rocks is decided by the distribution characteristics of the metallogenic elements in the upper mantleAn important reason for the adakitelike magma related to subduction being advantageous to mineralization is that there were abundant high pressure and high temperature liquid coming from the subducted platepieces and the magma of high fO2 coming from the melting of subducted platepiecesHowever, for those adakitelike rocks, whose occurrence has continental plate background but does not relate to the subduction, their metallogenic mechanism is not clear yetBased on the concept of modern mineral exploration and combined with the analysis of integrated geological information, we may better realize the practical prospecting significance of the adakitelike rocks

根据起源于下地壳的中酸性岩浆岩的成分变化，可以约束其源区深度以及地壳最小厚度，为大陆板内成矿作用的深部过程研究提供重要信息。全球范围内，许多世界级斑岩铜矿和浅成热液矿化系统与同期的埃达克质岩存在密切的时空与成因联系，在国内主要成矿区带也识别出与金属成矿作用有关的埃达克岩。与俯冲过程无关的埃达克质岩的识别，使我们有可能结合其他地质证据构建完全不同于Sillitoe(1972)B型俯冲环境的斑岩铜矿成矿模式的大陆板内斑岩型金属矿床成矿模式。对于规模巨大、矿质主要源自地幔的热液矿床的形成，埃达克岩可能是必要条件，但不是充分条件。埃达克岩的成矿潜力通过地幔物质加入而获取，埃达克岩的成矿专属性由上地幔成矿元素分布特征决定。与俯冲有关的埃达克质岩浆之所以有利于成矿，重要的原因是存在大量来自俯冲板片的高压、高温流体以及俯冲板片熔融形成高氧逸度(fO2)的熔体，但产出在大陆板内背景、与俯冲无关的埃达克岩的成矿机制还不清楚。根据现代资源勘查理念，结合综合地质信息分析，埃达克质岩具有实际找矿意义。

However, relating to investigate the modes, courses and characteristics of the orogenetic process in Paleozoic and after orogenetic process, the cognitive divergence have still occurred.

通过对新疆北东部地区不同构造区带构造作用的方式、过程和特点的研究，确定：①南天山榆树沟高压麻粒岩地体的正变质原岩是一个基本完整的蛇绿岩套，其经历了俯冲至下地壳的高压麻粒岩相、构造抬升至深地壳麻粒岩相以及快速构造折返至角闪岩相的变质过程，代表了南天山洋壳俯冲、变质、随后折返的过程，并首次确定了变质过程的PTt轨迹；②奥陶纪末期中天山北缘发生洋盆俯冲、地体增生作用，此时萨日达拉地区处于岛弧活动带；中石炭世晚期中天山小型洋盆关闭，准噶尔地块与伊犁—中天山板块斜向对接随后发生脆韧性质近水平高温低速右行走滑剪切；③根据巴音沟地区不构成蛇绿岩套有效成分的硅质岩具有与活动大陆边缘密切相关的地球化学特征以及洋中脊玄武岩显示其岩浆源区受到消减带流体交代作用的影响，结合区域地质资料，首次提出巴音沟蛇绿岩带所代表的洋盆古构造环境为弧后盆地，并于早石炭世至中石炭世末期间，经历了扩张、收缩和闭合过程；④首次在克拉麦里蛇绿混杂岩带中分解出具有N-MORB、T-MORB与OIB三种不同类型的火山岩岩石组合，反映了洋盆俯冲

The main work of this dissertation is as follow:Based on understanding teleseismic waveform utilization, history of receiver function development, extract receiver function, receiver function inversion and stack, debug the receiver function extract and inversion routine.

同时日本海俯冲带是世界上最古老的俯冲带之一，是研究俯冲带的俯冲对大陆构造运动的影响，俯冲板块与地幔的相互作用，特别是俯冲板块对地幔间断面形态的影响以及俯冲带是否穿过660km间断面等问题的最佳场所。

The results are shown as below.1 Tectono-thermal evolution: The history of the Songliao basin is divides into four stages, high-temperature doming and extension, high-temperature rifting, low-temperature depression, and low-temperature shrinkage. Numerical simulation of mechanical process shows that the basin appeared in the early- to late- Jurassic as a result of rapid low-angle subduction of the Pacific plate towards the northwest, of movement of the Siberian block towards the southeast, of many other influences such as internal thermal stress in the mantle, gravitational force, stress of phase transition, etc. Both the Pacific plate and the Siberian block slowed down in the early Cretaceous, and almost stopped in the middle Cretaceous with the rapid decrease of abnormal heat in the mantle below.

盆地构造热演化力源机制数值模拟研究表明：早、中侏罗世至晚侏罗世晚期，盆地演化主要是太平洋块体向北西方向以低角度快速俯冲和西伯利亚块体向东南俯冲共同作用的结果，同时也与地幔内部热力、重力、相变力以及地球自转及公转速度变化效应和上覆块体绝对运动的作用有关；早白垩世早期至早白垩世中期，来自东部太平洋块体俯冲作用的减弱，而这一时期影响盆地演化的主要力源是地幔内部热力、重力、相变力以及地球自转及公转速度变化效应和来自西伯利亚块体俯冲作用；进入早白垩世晚期至晚白垩世早期，由于双重俯冲带中西侧俯冲作用带基本停止活动，而本区地幔热能的快速衰减则控制盆地的构造热演化；晚白垩世晚期以后，太平洋块体活动加强和地幔热运动是影响盆地演化的主要动力。

At the convergent boundaries of plates, when one plate subducts into the another, the form of the subduction boundaries bears a close relation with the properties of the subducting and subducted plates.

在板块的汇聚边界上，若一板块向另一板块俯冲下插，所形成的俯冲边界的形态与俯冲板块、被俯冲板块的性质有很大关系。

The Kuriles subuction zone subducts with an angle of 45°; while the subducting angle of the Japan Sea subduction zone may by smaller 30°; the Ryukyu and Izu-Bonin subduction zones subducts with an angle of over 70° or nearly 90°, providing an evidence for activities in back-arc basins.

千岛群岛俯冲带大约以45°角度俯冲，日本海俯冲带则可能小于30°，琉球群岛俯冲带和伊豆-小笠原俯冲带则以大于70°的角度或近于直立的角度俯冲，从而为弧后盆地的活动性提供了证据。

As she looked at Warrington's manly face, and dark, melancholy eyes, she had settled in her mind that he must have been the victim of an unhappy attachment.

每逢看到沃林顿那刚毅的脸，那乌黑、忧郁的眼睛，她便会相信，他一定作过不幸的爱情的受害者。

Maybe they'll disappear into a pothole.

也许他们将在壶穴里消失