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subduction

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subduction n.1. 減去，取回，扣除；【數學】減法。 2. 【地質...

n. 1. 減去，取回，扣除；【數學】減法。 2. 【地質學；地理學】潛沒(使一個地殼板塊下降到另一板塊之下)。 “subduction zone, subduction belt“ 中文翻譯：   消減帶“flipped subduction“ 中文翻譯：   翻轉俯沖“intercontinental subduction“ 中文翻譯：   陸間俯沖“intracontinental subduction“ 中文翻譯：   陸內俯沖“oblique subduction“ 中文翻譯：   斜插俯沖“plate subduction“ 中文翻譯：   板塊俯沖作用“polarity of subduction“ 中文翻譯：   俯沖極性“sag subduction“ 中文翻譯：   沉陷俯沖作用“subduction belt“ 中文翻譯：   俯沖帶“subduction complex“ 中文翻譯：   俯沖復合體；俯沖帶雜巖“subduction plate“ 中文翻譯：   俯沖板塊; 下降板塊“subduction zone“ 中文翻譯：   潛沒帶; 潛沒區域; 消減帶; 隱沒帶；俯沖帶“accretionary subduction complex“ 中文翻譯：   加積俯沖復合體“active and inactive subduction zones“ 中文翻譯：   活動和停滯俯沖帶“back-arc subduction“ 中文翻譯：   弧后俯沖“continental subduction zone“ 中文翻譯：   大陸府沖帶“fossil subduction zone“ 中文翻譯：   古沉沒帶; 古消減帶“oceanic plate subduction“ 中文翻譯：   大洋板塊消減作用“palaeo-subduction zone“ 中文翻譯：   古俯沖帶“subduction orogenic belt“ 中文翻譯：   俯沖造山帶“trench-type subduction zone“ 中文翻譯：   海溝型消減帶“subductingplate“ 中文翻譯：   俯沖板塊“subducting plate“ 中文翻譯：   俯沖板塊“subducting lower plate“ 中文翻譯：   俯沖下層板塊“subducting lithosphere“ 中文翻譯：   消減的巖石圈“subducting edge“ 中文翻譯：   俯沖邊界

subdue

The mantle source for the mesozoic mafic volcanic rocks in yanshan area exhibit transition character in space and time : the mantle source components vary from subduction - related metasomatic components and emi components through dominant emi components and slight subduction - related metasomatic components to emi components ; spatially , mantle source of the volcanic rocks show a regular variation trend from an enriched lithospheric mantle with emi - like signatures in the western shandong province through emi and / or subduction - related metasomatic components in yanshan area to subduction - related metasomatic lithospheric mantle in the hinggan - mongolian orogen 燕山地區中酸性火山巖則來源于地殼，與玄武質巖漿底侵作用關系密切。 3燕山地區火山巖源區組分在時空上具有一定的演化規律：在時間上，從早期俯沖交代地幔及emi的參與，經中期以emi占主導及極少量俯沖交代組分的階段，演變到晚期以emi為主，可能有少量軟流圈貢獻的組分，再到晚白堊世以軟流圈為主。

The pges abundance patterns of residual mantle rock with a peleo - subduction background is characterized by pd , pt depletion and ir , ru relatively enrichment , while the basalt and basic dyke by the processing of partial melt in the same background take an opposite feature of pd , pt enrichment and ir , ru depletion . the existence of fluid in the subduction zone increases the degree of partial melt on the one hand , and on the other , activates the activity of pd , pt compare to ir , ru , and thus reduces the pd ir and pt ru in residual mantle rock . the pges patterns for basalt and basic dyke from two carboniferous volcano zones to south qoltag and north turpan - hami basin , xinjing uigur autonomous region , take a shape of gentle positive inclined curve with lower pt and pd differentiation and lower pges . all these features are obviously different from that of basic dyke and basalt from typical ophiolite and therefore the author believe that their fluid - rich paleo - subduction zone environment can be ruled out 古俯沖帶背景下的殘余地幔巖的pges配分以pd , pt明顯虧損和ir , ru相對富集為特征，而部分熔融產物的玄武巖和基性巖脈則呈現相反的ir , ru明顯虧損和pd , pt相對富集特征。俯沖帶中流體的參與一方面增加了部分熔融程度，有利于pd , pt從原始地幔進入熔融相另一方面，流體的作用使得pd , pt相對于ir , ru遷移活動性效率提高，造成地幔巖中

Geologists and geophysicists have carried out substantial work on petrology , geochemistry , chronology and geophysics , et al . , which yields important reference material and constrains for explanations of questions , such as the delamination and exhumation mechanism for the lower crust , models of the rapid uplift of himalayan orogen and deep subduction of india - eurasia plate . while only a little has been done to study the eastern syntaxis at present 地質學家和地球物理學家已經對西構造結進行了大量的巖石學、地球化學、年代學和地球物理學等方面的研究，為解釋下地殼的拆沉、折返機制，喜馬拉雅造山帶的快速隆升和印度-歐亞板塊的大陸深俯沖模式等提供了重要的參考信息和約束條件。

We deduce that it is a relic old crust that was brought upwards during the formation of neo - tethyan ophiolite . the step heating 40ar - ' 9ar spectra show that during 100ma , luobusha ophiolite suffered intensely alternation , which affected distinctly the k - ar system ; during 771ma some basalt formed in the country rock of xiubugabu ophiolite ; during 55ma , the pillow basalt of rikangba ophiolite affected by a strong thermal event ; all the variety of ages illustrates possible impacts of the subduction - collision between india and eurasia . through dissecting mainly the gabbro of luobusa ophiolite and studying the 40ar / 39ar ~ ( 40 ) ar ~ ( 39 ) ar階段升溫年齡圖譜顯示， 100ma左右羅布莎巖體經歷了較強的后期蝕變作用，對其k ? ar體系造成明顯影響； 77 1ma休古嘎布巖體圍巖中形成玄武質火山集塊巖； 55ma日康巴巖體巖石枕狀玄武巖受到較強熱事件影響；這些~ ( 40 ) ar - ~ ( 39 ) ar年齡上的變化顯示了印度板塊與歐亞板塊俯沖?碰撞對該區的強烈影響。

Secondly , based on the microbeam analytical technique , on the one hand , through investigating the characteristic of major elements in the mantle minerals the author acquired the static information from mantle ; on the other hand , through multi - point analysis of a part of the minerals from mantle , the auther got dynamic information from mantle . finally , generalizating the fruits of this study and predecessors , the autor holds that the constituents of lithospheric mantle possibly includes spinel lherzolites , clinopyroxenites , websterite , dunite , harzburgites , garnet lherzite , phlogopite lherzite , eclogites , clinopyroxene megacrysts ; compared with east china and north china platform , the research field mantle shows the characteristics of higher degree of partial melting processes and more depleted mantle ; the . upper mantle beneath north hetian area is heterogeneous , with a tendency of deficit in a12o3 and lree from kaliyang in west hetian to the river basin of kalakshi river and yulongkashi river ; the subduction of the crust beneath north hetian has ever occurred in geological history and caused the mixing of mantle - crust ; the depth of the origination of basaltic magmas beneath north hetian exceeds 73km ; the thickness of the lithosphere beneath the research area amounts to 204 . 9km ; the mantle beneath north hetian has geological condtions for forming diamond deposits 最后，綜合本區幔源礦物和地幔巖石的特征以及地球物理資料，得出如下結論：本區上地幔的物質組成有尖晶石二輝橄欖巖、二輝巖、單斜輝石巖、純橄欖巖、方輝橄欖巖、石榴石二輝橄欖巖、金云母二輝橄欖巖、榴輝巖；與中國東部以及華北地臺上地幔相比，研究區上地幔具有富集主元素中相容元素和虧損其中的不相容元素的特征，局部熔融程度較高；上地幔存在橫向和縱向的不均一性，從西部的克里陽到喀拉喀什河和玉龍喀什河流域， al和lree富集程度呈下降趨勢，不同來源的相同礦物中主元素的含量差異較大；地質歷史時期這里可能發生過地殼俯沖并產生殼幔混合作用；玄武巖漿的起源深度73km ；從幔源重砂礦物的溫壓估算結果，可以推斷出巖石圈厚度可達204 . 9km ；綜合巖石圈物質組成特征、巖石圈熱狀態、地幔溫壓狀態、氧逸度以及幔源巖石和幔源礦物的化學成分，認為研究區具備了金剛石成礦地幔地質條件。

The formation dynamic mechanisms is very complicated . the uplifting and thickening of crust are the result of various causes . but the main reason is the plate subduction which is the basic cause to have the gravitation , thermo - dome and stretching force become useage 青藏高原處于復雜的動力體制中，陸殼增厚和隆升是各種因素共同制約的結果，但板塊俯沖機制是主導的，是使其它力源，如重力、熱動力和張力等成為有效驅動力機制的基本因素。

In the jinshajiang suture zone , it lasted only a span of 9 ma from the start of subduction ( marked by the eruption of andesitic magmas and intrusion of intermediate rock of iag type at about 227 ma ) to the end of subduction , consumption of oce Iv期： 45ma以來，高原快速抬升；斷裂系活化，產生大規模走滑活動；巖體或被斷層切割、遷移，或抬升剝蝕。 ivi ： 45 25mi ，巖體和整個青藏高原一起呈周期性的、脈動式抬升。

During subduction northward of neo - tethys oceanic plate , ayla - zhongba micro - continental , the marginal ocean basin and india continental drifted northward all together , the marginal ocean basin was gradually contracted and closed by compressed of india continental 在新特提斯洋板塊向北俯沖消減過程中，阿依拉仲巴微陸塊、陸緣洋盆和印度大陸一起隨著向北漂移，在印度大陸向北擠壓作用下洋盆逐漸收縮以致最終閉合。

Among different opinions , the most popular one is that the temporal and spatial distribution and evolution of the gangdise plutonic - volcanic belt are controlled by the northward subduction of the yarlung zangbo oceanic crust and the southward subduction of the bangong - nujiang oceanic crust 在眾多的觀點中較權威的觀點，是岡底斯巖漿帶的時空分布與演化受控于雅魯藏布江洋殼和班公湖-怒江洋殼分別向北向南俯沖。

At the course of subduction , collision and collage among the siberia , khazakstan and junggar blocks , the geotectonic environment underwent a few evolutional stages , they provided good congenital , parturient and postnatal conditions for the deposit 在西伯利亞、哈薩克斯坦準噶爾板塊多階段的俯沖、碰撞、拼合過程中，礦床所處的大地構造環境經歷了多個開合演化階段，為該礦床提供了良好的先天、臨產及后天條件。

In the case of africa , already sliding eastward , the force is further movement eastward , as subduction of the indio - australian plate has already begun , the weaker link already established and momentum in process 在非洲大陸已經向東方滑動了的情況下， （原先存在的）壓力被進一步轉移到東方，因為印澳板塊的縮減已經發生，板塊之間已經建立了不牢固的連接，板塊移動的動力也被轉化了。

If all goes well , the hybrid rov will let scientists better understand fundamental processes occurring at the deep subduction zones along the continental margins where geochemical recycling of the earth ' s crust takes place 如果一切都進行得很順利，復合型遙控探測器將可使科學家更清楚地了解，發生在大陸邊緣海洋深處隱沒帶的地質變化，以及此處地殼物質所進行的地球化學循環內容。

However , the age of the rock closely approximates the timing of low - angle oblique subduction of an ancient pacific plate , high - pressure metamorphic event , uplift of the pingtan - dongshan metamorphic belt and movement along the changle - nanao shear zone 時間上與古太平洋板塊低角度?歪斜俯沖、晚中生代的變質事件、平潭?東山變質帶抬升和長樂?南澳剪切帶運動在時間上基本一致。

A third possibilty is that ivc colapsed primarily due to natural reasons ( climate change , tectonic activity along the subduction zone along the indo - asian plate boundary ) and that there was no indo - aryan invasion that took place 印度河流域文明衰落的第三個可能是由于自然因素（氣候改變，伴隨著印度雅利安人進入的可建造區域減少） ，并沒有印度雅利安人入侵的發生。

These comparative studies indicate that the horizontal differences become apparent in the styles and strength of the subduction and collision between the indian continent and eurasian continent 通過高原南緣橫向地球物理特征的對比，發現該地區東、西兩側深部巖石圈結構存在明顯不同，表明印度次大陸向歐亞大陸俯沖碰撞的方式和強度在橫向上差異明顯。

These intrusive rocks are the products of the closure of the yarlung zangbo and banggonghu - nujiang oceanic basins and may represent three magma - induced thermal disturbance events of plate subduction , collision , and post - collision 它們是雅魯藏布江洋盆和班公湖-怒江洋盆關閉的產物，主體代表了板塊俯沖、碰撞和碰撞后三個時期的巖漿熱擾動事件。

At last they have being formed the tectonic framework , after breakup of the volcanic island arcs , subduction , decline and fall of the back - arc basins and arc - microcontinent and arc - arc collision had finished 經過了長期而復雜的微大陸和火山弧的裂解、弧后盆地的消減衰亡及弧陸和弧弧碰撞等構造演化，才最終形成今天所見到的這種構造樣式。

Due to the subduction of pacific palte under eurasian in early cretaceous , at about 140 ma , fast collapse ( delamination ) took place and the mantle plume emerged , both resulted in the large - scale crustal extension in ludong 3 、富集地幔源區( em1 )的產生是俯沖并熔融的揚子下地殼物質進入華北巖石圈地幔并與之相互交代作用形成的。

Path of uhpm consists of two curves , i . e . , a barrette - like curve reflecting the process of cold slab subduction and exhumation cold overthrusting , and a crescent curve representing the thermal exhumation after slab breakoff 軌跡由兩部分組成，即反映板片冷俯沖冷折返過程的發夾狀曲線和指示板片斷離拆沉熱折返過程的新月形曲線。