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1.
１．ＩｎｔｒｏｄｕｃｔｉｏｎＦｉｇ．１．　ＲｅｇｉｏｎａｌｇｅｏｌｏｇｙｏｆｔｈｅｅａｓｔｅｒｎＬｉａｏｎｉｎｇＳｏｕｔｈｅｒｎＪｉｌｉｎａｒｅａ（ＡｆｔｅｒＺｈａｎｇ,１９８４）　　ＴｈｅＰａｌｅｏｐｒｏｔｅｒｏｚｏｉｃｖｏｌｃａｎｉｃｓｅｄｉｍｅｎｔａｒｙｓｅｑｕｅｎｃｅ,ｉ．ｅ．,ｔｈｅＳｏｕｔｈＬｉａｏｈｅＧｒｏｕｐａｎｄＮｏｒｔｈＬｉａｏｈｅＧｒｏｕｐ,ｅｘｔｅｎｄｓｂｅｔｗｅｅｎｔｗｏＡｒｃｈａｅａｎｃｒａｔｏｎｓ（Ｆｉｇ．１）．Ａｂｕｎｄａｎｔｍｉｎｅｒａｌｒｅｓｏｕｒｃｅｓ…  相似文献   

2.
１．ＩｎｔｒｏｄｕｃｔｉｏｎＦｉｇ．１．　ＴｅｃｔｏｎｉｃｐｏｓｉｔｉｏｎｏｆｔｈｅＤａｂｉｅｏｒｏｇｅｎｉｃｂｅｌｔａｎｄＴａｎＬｕｆａｕｌｔｉｎｅａｓｔｅｒｎＣｈｉｎａ　　ＴｈｅＤａｂｉｅｏｒｏｇｅｎｉｃｂｅｌｔａｎｄＴａｎＬｕｓｔｒｉｋｅｓｌｉｐｆａｕｌｔａｒｅｓｉｔｕａｔｅｄｉｎｃｅｎｔｒａｌａｎｄｅａｓｔｅｒｎＣｈｉｎａ,ｒｅｓｐｅｃｔｉｖｅｌｙ（Ｆｉｇ．１）．Ｔｈｅｉｒｅｖｏｌｕｔｉｏｎａｒｙｐｒｏｃｅｓｓｅｓ,ｒｅｌａｔｅｄｔｏｔｈｅａｄｊａｃｅｎｔｇｅｏｌｏｇｉｃｂｌｏｃ…  相似文献   

3.
ＩＮＴＲＯＤＵＣＴＩＯＮＭｏｌｅｃｕｌａｒｎｉｔｒｏｇｅｎ（Ｎ２）ｉｓｏｎｅｏｆｔｈｅｍｏｓｔｃｏｍｍｏｎｎｏｎｈｙｄｒｏｃａｒｂｏｎｃｏｍｐｏｎｅｎｔｓｉｎｇａｓｐｏｏｌｓ（Ｚｈｕ,１９９４）．Ｎ２ｒｉｃｈｇａｓｐｏｏｌｓｈａｖｅｂｅｅｎｄｉ...  相似文献   

4.
Barium Anomaly and Its Geochemical Significance   总被引：2，自引：0，他引：2  
１．Ｉｎｔｒｏｄｕｃｔｉｏｎ　　Ｍｕｌｔｉｅｌｅｍｅｎｔｖａｒｉａｔｉｏｎｄｉａｇｒａｍｓａｒｅｖｅｒｙｕｓｅｆｕｌｉｎｔｈｅｇｅｏｃｈｅｍｉｃａｌｓｔｕｄｙ．ＯｎｅｏｆｔｈｅｍｉｓｔｈｅＰｅａｒｃｅｄｉａｇｒａｍ,ｔｈｅＭＯＲＢｎｏｒｍａｌｉｚｅｄｍｕｌｔｉｅｌｅｍｅｎｔｖａｒｉａｔｉｏｎｄｉａｇｒａｍｇｉｖｅｎｂｙＰｅａｒｃｅ（１９８３）．ＴｈｉｓｄｉａｇｒａｍｓｈｏｗｓｔｈｅｒｅｌａｔｉｖｅｄｅｐｌｅｔｉｏｎｓｏｆＨＦＳｅｌｅｍｅｎｔｓＮｂ,ＴｉａｎｄＰ．Ｉｎａｄｄｉｔｉｏｎ,ｔｈｅ…  相似文献   

5.
１－Ｉｎｔｒｏｄｕｃｔｉｏｎ　ＴｈｅｏｒｏｇｅｎｉｃｂｅｌｔｏｆＩｎｎｅｒＭｏｎｇｏｌｉａｉｓｌｏｃａｔｅｄｂｅｔｗｅｅｎｔｈｅＮｏｒｔｈＣｈｉｎａＣｒａｔｏｎａｎｄｔｈｅＳｉｂｅｒｉａｎＰｌａｔｆｏｒｍ．ＴｈｉｓｂｅｌｔｉｓｃｏｎｓｉｄｅｒｅｄａｐａｒｔｏｆｔｈｅＣｅｎｔｒａｌＡｓｉａＭｏｎｇｏｌｉａｎｇｅｏｓｙｎｃｌｉｎｅ（ＩｃｈｉｋａｗａａｎｄＷａｎｇ,１９９１）ｏｒＣｅｎｔｒａｌＡｓｉａｎＭｏｎｇｏｌｉａｎｍｏｂｉｌｅｂｅｌｔ．ＴｈｅｎｏｒｔｈｅｒｎｌｉｍｉｔｏｆｔｈｅＮｏｒｔｈＣ…  相似文献   

6.
１．Ｉｎｔｒｏｄｕｃｔｉｏｎ　　Ｔｈｅｄａｔａｏｆｔｈｉｓｓｔｕｄｙａｒｅｃｏｌｌｅｃｔｅｄｆｒｏｍ２１６ｍａｇｎｅｔｏｔｅｌｌｕｒｉｃｓｏｕｎｄｉｎｇｐｏｉｎｔｓｏｎｔｈｅｆｏｌｌｏｗｉｎｇｐｒｏｆｉｌｅｓａｃｒｏｓｓｔｈｅＱｉｎｌｉｎｇｏｒｏｇｅｎ,ｔｈｅＹｅｘｉａｎ（ｉｎＨｅｎａｎＰｒｏｖｉｎｃｅ）－Ｎａｎｚｈａｎｇ（ｉｎＨｕｂｅｉＰｒｏｖｉｎｃｅ）Ｐｒｏｆｉｌｅ（Ｌｉｅｔａｌ．,１９９８）,ｔｈｅＬｕｏｙａｎｇ（ｉｎＨｅｎａｎＰｒｏｖｉｎｃｅ）－Ｓｈｉｙａｎ（ｉｎＨｕｂｅｉＰｒｏｖｉｎ…  相似文献   

7.
１．ＩｎｔｒｏｄｕｃｔｉｏｎＧｕｄａｏｏｉｌｆｉｅｌｄｌｏｃａｔｅｓｉｎＨｅｋｏｕｄｉｓｔｒｉｃｔｏｆＤｏｎｇｙｉｎｇｃｉｔｙ,Ｓｈａｎｄｏｎｇｐｒｏｖｉｎｃｅ,ｗｈｉｃｈｌｉｅｓｏｎａｌａｒｇｅｓｃａｌｅｄｒａｐｅｓｔｒｕｃｔｕｒａｌｂｅｌｔｏｆ...  相似文献   

8.
ＳＯＭＥＮＥＷＯＰＩＮＩＯＮＳＡＢＯＵＴＴＲＩＡＳＳＩＣＧＡＳＴＲＯＰＯＤＡＳＳＥＭＢＬＡＧＥＳＩＮＣＨＩＮＡＰａｎＹｕｎｔａｎｇ（ＧｒａｄｕａｔｅＳｃｈｏｌ，ＣｈｉｎｅｓｅＡｃａｄｅｍｙｏｆＳｃｉｅｎｃｅｓ，Ｂｅｉｊｉｎｇ１０００３９）（Ｒｅｃｅ...  相似文献   

9.
ＳＴＵＤＹＯＦＯＩＬＦＩＥＬＤＫＡＲＳＴＨａｎＢａｏｐｉｎｇＣｏｌｅｇｅｏｆＭｉｎｅｒａｌ．ＲｅｓｏｕｒｃｅａｎｄＥｎｖｉｒｏｎｍｅｎｔＳｃｉｅｎｃｅｓ，ＣｈｉｎａＵｎｉｖｅｒｓｉｔｙｏｆＭｉｎｉｎｇａｎｄＴｅｃｈｎｏｌｏｇｙ，Ｘｕｚｈｏｕ２２１...  相似文献   

10.
Ｗｅｃｏｌｅｃｔｅｄｏｒｉｅｎｔｅｄｍａｇｎｅｔｏｓｔｒａｔｉｇｒａｐｈｉｃｓａｍｐｌｅｓａｔｔｈｅｓａｍｅｂｅｄ（Ｂｅｄ２７,ｌｉｍｅｓｔｏｎｅ）ｏｆＡａｎｄＤｓｅｃｔｉｏｎｓｎａｍｅｄｂｙＳｈｅｎｇｅｔａｌ．（１９８４）ｏｆＭｅｉｓｈａｎｓｅｃｔ...  相似文献   

11.
Ｐｅｔｒｏｇｅｎｅｓｉｓ　ｏｆ　Ｅｃｌｏｇｉｔｅｓ　ｉｎ　ｔｈｅ　Ｌｉｇｈｔ　ｏｆ　ＰｕｎｃｔｕａｔｅｄＭｅｔａｍｏｒｐｈｉｃ　Ｅｖｏｌｕｔｉｏｎ　ｉｎ　Ｄａｂｉｅ　Ｔｅｒｒａｎｅ，Ｃｈｉｎａ￥ＹｏｕＺｈｅｎｄｏｎｇ；ＨａｎＹｕｊｉｎｇ；ＺｈｏｎｇＺ...  相似文献   

12.
大别山产出的榴辉岩相岩石包括石榴橄榄岩、榴辉岩、榴云片岩、榴辉片麻岩、榴玉英岩和榴辉大理岩等不同系列,它们均分布于花岗质片麻岩中。矿物共生序列研究表明,榴辉岩相岩石经历了从绿帘角闪岩相、柯石英榴辉岩相、角闪榴辉岩相、绿帘角闪岩相到绿片岩相的演化过程。花岗质片麻岩及变质火山—沉积岩系并未经历超高压变质作用,但却与榴辉岩相岩石经历了同一期绿帘角闪岩相变质事件,证明二者在地壳范围内发生了构造合并  相似文献   

13.
俯冲隧道是俯冲板片与上覆板块之间的剪切带,也是高压—超高压变质岩折返和深部流/熔体活动的通道。大别山超高压变质岩分布广泛,变形程度差异很大,是研究大陆俯冲隧道中岩石变质- 变形过程的理想地区。本文系统总结了前人对中大别双河地区超高压变质岩的岩石学和年代学研究成果,在双河地区开展了地质填图、应变分析和三维构造重建。通过将超高压变质岩的变形特征与P- T- t轨迹结合,识别出超高压变质岩折返过程中的三期韧性变形。在双河北部发现了一个上盘向NW剪切的千米尺度的榴辉岩相鞘褶皱,枢纽向SE倾伏,倾伏角约20°,与榴辉岩、片岩和长英质片麻岩的拉伸线理平行,表明超高压变质岩初始折返阶段的流体活动使榴辉岩的强度显著降低,榴辉岩与围岩一起发生韧性变形。该期变形被角闪岩相退变质阶段上盘向NW的剪切叠加,此时应变集中于片麻岩、片岩、大理岩等非能干层,强度较高的榴辉岩成为构造透镜体。而绿片岩相变质阶段上盘向SE方向的剪切与早白垩世北大别花岗片麻岩穹隆的形成有关。对双河南部弱变形花岗片麻岩的锆石U- Pb定年揭示了757±14 Ma的原岩年龄和 240~216 Ma的变质年龄,与双河北部含柯石英强变形花岗片麻岩类似,暗示其也经历了三叠纪超高压变质作用及随后的角闪岩相退变质作用。通过计算长英质片麻岩的有效黏度,发现无水碱长花岗片麻岩的有效黏度高于黑云斜长片麻岩,折返阶段的流体活动使超高压变质岩的强度显著降低,当局部的流体活动不足以弱化碱长花岗岩体时,应变集中于黑云斜长片麻岩。因此,大陆俯冲隧道中的应变分布受矿物组成、流体活动和岩体规模的共同影响。  相似文献   

14.
Five kinds of UHP metamorphic rocks, including eclogite, orthogneiss, paragneiss, schist and quartzite are exposed in the Qinglongshan roadcut, southern Sulu orogenic belt of eastern central China. They comprise metamorphic supracrustal rocks with bimodal volcanic characteristics and continental affinity, and granitic intrusive associations. The preservation of coesite inclusions and/or its pseudomorphs in eclogite and other rocks indicate that they have been subjected to in-situ UHP metamorphism. Four stages of metamorphism were recognized by combining petrographic observations and compositions of minerals from various UHP rocks. Prograde epidote-amphibolite facies, UHP coesite–eclogite facies, post UHP quartz–eclogite facies, and retrograde amphibolite facies assemblages delineate an inferred P–T path with a clockwise trajectory and a retrograde event characterized by the coupling of decompression with a temperature decrease. Garnet porphyroblasts in UHP eclogites display a complex growth zoning and mineral distribution, and record a crucial segment of the prograde and retrograde metamorphic evolution. The preservation of growth zoning in eclogitic and gneissic garnets suggests that the UHP rocks had a short residence time before retrograde metamorphism and a very high uplift rate in order to preserve the prograde growth zoning.  相似文献   

15.
《China Geology》2021,4(1):111-125
High/ultrahigh-pressure (HP/UHP) metamorphic complexes, such as eclogite and blueschist, are generally regarded as significant signature of paleo-subduction zones and paleo-suture zones. Glaucophane eclogites have been recently identified within the Lancang Group characterized by accretionary mélange in the Changning-Menglian suture zone, at Bangbing in the Shuangjiang area of southeastern Tibetan Plateau. The authors report the result of petrological, mineralogical and metamorphism investigations of these rocks, and discuss their tectonic implications. The eclogites are located within the Suyi blueschist belt and occur as tectonic lenses in coarse-grained garnet muscovite schists. The major mineral assemblage of the eclogites includes garnet, omphacite, glaucophane, phengite, clinozoisite and rutile. Eclogitic garnet contains numerous inclusions, such as omphacite, glaucophane, rutile, and quartz with radial cracks around. Glaucophane and clinozoisite in the matrix have apparent optical and compositional zonation. Four stages of metamorphic evolution can be determined: The prograde blueschist facies (M1), the peak eclogite facies (M2), the decompression blueschist facies (M3) and retrograde greenschist facies (M4). Using the Grt-Omp-Phn geothermobarometer, a peak eclogite facies metamorphic P-T condition of 3000–3270 MPa and 617–658°C was determined, which is typical of low-temperature ultrahigh-pressure metamorphism. The comparison of the geological characteristics of the Bangbing glaucophane eclogites and the Mengku lawsonite-bearing retrograde eclogites indicates that two suites of eclogites may have formed from significantly different depths or localities to create the tectonic mélange in a subduction channel during subduction of the Triassic Changning-Menglian Ocean. The discovery of the Bangbing glaucophane eclogites may represent a new oceanic HP/UHP metamorphic belt in the Changning-Menglian suture zone.©2021 China Geology Editorial Office.  相似文献   

16.
大别山北部榴辉岩及英云闪长质片麻岩的锆石U-Pb年龄分析表明：北部榴辉岩相峰期变质时代为226～230Ma左右;北部塔儿河一带英云闪长质片麻岩经历过印支期变质事件;大别山北部与南部超高压岩石中一致的（226～230Ma）高压或超高压变质年龄表明,北部镁铁-超镁铁质岩带中部分岩石也曾作为扬子俯冲陆壳的一部分,在印支期发生过高压或超高压变质作用;本区锆石发生过两期变质增生事件,一是印支期高压或超高压变质,另一期是燕山期热变质事件;榴辉岩及英云闪长质片麻岩的原岩形成时代为晚元古代;锆石U-Pb年龄可用多期变质增生模型来解释。  相似文献   

17.
根据大别山高压、超高压变质岩的中尺度-显微构造分析及PTt研究,建立它们的结构和构造随变质作用（前榴辉岩相、超高压变质峰期、前角闪岩相和角闪岩相）有序演化的PTt-D轨迹。这一演化主要包括：在岩石的矿物结构方面从石榴石静态重结晶结构到柯石英假像及放射状张裂隙构造;在岩石组构方面从L>S到L-S和S>L榴辉岩;以及在中尺度构造方面发育的D1和D2变形构造。该PTt-D轨迹同时可以提供有关高压、超高压变质岩折返模式的信息。  相似文献   

18.
Recently, a huge ultrahigh‐pressure (UHP) metamorphic belt of oceanic‐type has been recognized in southwestern (SW) Tianshan, China. Petrological studies show that the UHP metamorphic rocks of SW Tianshan orogenic belt include mafic eclogites and blueschists, felsic garnet phengite schists, marbles and serpentinites. The well‐preserved coesite inclusions were commonly found in eclogites, garnet phengite schists and marbles. Ti‐clinohumite and Ti‐chondrodite have been identified in UHP metamorphic serpentinites. Based on the PT pseudosection calculation and combined U‐Pb zircon dating, the P‐T‐t path has been outlined as four stages: cold subduction to UHP conditions before ～320 Ma whose peak ultrahigh pressure is about 30 kbar at 500oC, heating decompression from the Pmax to the Tmax stage before 305 Ma whose peak temperature is about 600oC at 22kbar, then the early cold exhumation from amphibolite eclogite facies to epidote‐amphibolite facies metamorphism characterized by ITD PT path before 220 Ma and the last tectonic exhumation from epidote amphibolite facies to greenschist facies metamorphism. Combining with the syn‐subduction arc‐like 333‐326 Ma granitic rocks and 280‐260 Ma S‐type granites in the coeval low‐pressure and high‐temperature (LP‐HT) metamorphic belt, the tectonic evolution of Tianshan UHP metamorphic belt during late Cambrian to early Triassic has been proposed.  相似文献   

19.
桐柏-大别山区高压变质相的构造配置   总被引：18，自引：3，他引：15  
作为华北和扬子陆块间的碰撞造山带桐柏大别山区以发育高压、超高压变质带为特征,从南到北变质相从低级到高级,代表俯冲带深度不同的变质产物,整体形成高压变质相系列。不过现今各变质相岩石的分布极受后期地壳规模的伸展构造控制,大别杂岩的穹隆作用更使高压变质相带的空间分布复杂化。超高压变质岩今日多呈大小不等的块体嵌布于相对低压的大别杂岩之内,造山带根部物质的热软化,使许多深层地幔物质得以像挤牙膏一样挤出于大别杂岩内。它们之中广泛发育着减压退变质的显微结构,与大别杂岩内一些麻粒岩相表壳岩所保存的减压退变质证迹一样,同是挤出作用和碰撞后隆升的构造证迹。高压相系的发育使南桐柏山和大别山迥然不同于桐商（ 商丹） 断裂以北的北秦岭北淮阳变质带。新近发表的同位素年代学（４０Ａｒ ３９ Ａｒ） 资料：３１６ ～４３４ Ｍａ ,已证明北秦岭是古生代变质带,它与桐柏－ 大别印支期碰撞造山带差异甚大。这两个变质地温梯度差异甚大的变质地体的拼合,说明华北和扬子陆块碰撞的主缝合带是商丹－ 桐商断裂带  相似文献   

20.
The Qinling-Dabie-Sulu high-pressure and ultra-high pressure metamorphic belt wasformed by subduction and collision between the North China and Yangtze plates. The study ofthe eclogite belt is very important in understanding the evolution of the Qinling Dabie orogen. Inthe present paper the geology, petrology, minerology and chronology of the eclogites in the Dabieand Sulu areas are described. The principal conclusions of this work are as follows: (1) Based up-on the field occurrence and the P-T conditions of the eclogites, two types of eclogite can be dis-tinguished: Type 1—the low-temperature and high-pressure eclogite in the mid-late Proterozoicmetamorphic series, and Type 2—the ultra-high pressure eclogite in the late Archaean to earlyProterozoic metamorphic complex. In the Dabie area, the ultra-high-pressure eclogite,high-pressure eclogite and epidote-blueschist units are nearly parallel to each other and stretchintermittently from north to south. (2) The P-T conditions of the high-pressure eclogites and ul-tra-high pressure eclogites have been estimated. The former are formed at 450-550℃ and1.4-1.6 GPa; while the latter at 650-870℃ and >2.7-2.9 GPa in the Dabie area and at820-1000℃ and >2.8-3.1 GPa in the Sulu area. The metamorphic temperatures of the eclogitesincrease progressively from west to east. (3) The ultra-high pressure eclogites were subjected to 5stages of metamorphism: pre-eclogite epidote amphibolite facies, peak coesite eclogite facies,post-eclogite amphibolite facies, epidote-blueschist facies or epidote amphibolite facies andgreenschist facies. The general features of the PTt path of the ultra-high pressure eclogite are:clockwise pattern, progressive metamorphism being a process of slow increasing temperature andrapid increasing pressure, and the retrogressive section with nearly isothermal decompression atthe early stage, isobaric cooling at the middle stage and nearly isothermal decompression at thelate stage. (4) At least two stages of high-pressure metamorphism occurred in the orogenic belt:the high-pressure eclogite and ultra-high pressure eclogite were formed by the subduction of theoceanic crust northward beneath the North China plate or the Dabie block during theCaledonian; while the epidote-blueschist belt came into being by subdution and collision be-tween the two continental plates during the Indosinian. (5) Due to the continuous sequentialsubduction of the cold plate, the ultra high-presssure metamorphic rocks were uplifted to thecrust by the underplating processes. They can be preserved just because of the "frozen effect" re-sulting from the continuous subduction of the cold plate. (6) The carbonates, such as magnesite,breunnerite, aragonite and dolomite, and the H_2O-bearing minerals, such as phengite, epidoteand zoisite, were stable during the high-pressure and/or ultra-high pressure metamorphism.  相似文献   

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