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哀牢山-红河剪切带是东南亚重要的构造边界,其记录了青藏高原东南缘新生代以来的陆内变形和地貌演化。本次研究对该剪切带哀牢山南段开展了基于LA-ICPMS法测试的磷灰石裂变径迹低温年代学分析。磷灰石裂变径迹年龄数据和热史反演模拟揭示哀牢山段存在晚始新世-早中新世(40～20Ma)的快速剥露事件,而早中新世(大约20Ma)之后处于稳定的慢速剥露过程。磷灰石裂变径迹年龄-海拔分布曲线特征暗示:快速剥露机制存在差异,早期阶段(40～26Ma)的剥露过程受控于伸展为主的左旋走滑体制影响;晚阶段(26～20Ma)的快速剥露归因于简单剪切为主的左旋走滑剪切体制,上述结果暗示哀牢山-红河构造带在晚渐新世发生了一次重要的构造体制转换,即从走滑伸展变形转换为简单剪切变形。哀牢山杂岩带北段、中段、南段冷却路径对比,表明北-中段可能存在两阶段快速冷却作用,而南段只发生单一快速冷却作用;结合青藏高原东南缘低温热年代学数据,暗示自中-晚中新世,青藏高原中、下地壳物质可能向东南缘扩展,并已到达哀牢山中段,同时诱发哀牢山杂岩带以北广大地区的抬升和快速冷却。 相似文献
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笔者等通过对哀牢山—红河剪切带5件砂岩磷灰石样品裂变径迹分析,获得测试分析样品的表观年龄,对所有样品利用模拟退火法进行了热史模拟,取得其热演化史;得出哀牢山—红河剪切带在新生代发生了相似的构造演化过程,其经历了2次快速冷却剥露事件,分别发生在37～14 Ma和5. 1～0 Ma,平均冷却速率分别为3. 98℃/Ma和11. 15℃/Ma;在发生快速冷却的时间上,存在自东向西逐渐变晚的趋势,说明哀牢山—红河剪切带在新生代可能为自东向西的幕式隆升。 相似文献
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哀牢山-红河左旋走滑剪切带中新世抬升的时间序列 总被引：17，自引：1，他引：17
在哀牢山-红河剪切带的元阳到者龙的6个不同地点,对18个变质岩样品进行系统分析钾长石的~(40)Ar-~(39)Ar年龄。发现用MDD模式得到的18条冷却曲线(温度范围在400-150℃之间)均存在一次(或两次)快速冷却过程(冷却速度>100°C/Ma),这种快速冷却(抬升)过程不仅反映了该剪切带在大约25-17Ma时,韧性走滑作用结束和正断作用的开始,而且它的起始时间还有自东南向西北逐渐变新的趋势。利用6个不同地点快速冷却(抬升)的起始时间与相对距离作图时,得到了较好的线性函数关系(斜率为34mm/a) 相似文献
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中部地壳剪切带花岗质岩石变形及其对于构造-岩浆关系的约束:以滇西点苍山为例 总被引：1，自引：1，他引：0
哀牢山-红河剪切带剪切时间的厘定至今存在较多的争议,争议的本质更确切地说是对于剪切带内及其附近剪切作用与岩浆作用认识的差异。点苍山杂岩是位于哀牢山-红河剪切带北端的一个杂岩体,由西部的深变质岩、东部的叠加退变质带和不同时代的花岗质岩石组成。为了正确厘定剪切前、剪切期(包括剪切前期和剪切后期)、剪切后花岗质岩脉,剪切作用过程中构造变形与岩浆作用之间的关系,同时对哀牢山-红河剪切带剪切时间进行新的约束,本文围绕点苍山杂岩开展详细的宏观构造解析、显微构造观察和组构分析,以查明岩体(脉)岩浆流动构造和晶质塑性变形构造,同时对同剪切岩脉开展锆石U-Pb学分析。结果显示,剪切不同阶段就位的花岗质岩石具有不同的宏观构造、显微构造与组构特征。现今所见岩石变形构造、显微构造和组构特点一方面取决于递进剪切变形作用过程中的时间早晚,另一方面还与它们在递进剪切变形作用过程中的构造位置有密切联系。获得两组同剪切年龄为28.54±0.15Ma和27.31±0.23Ma,其中前者为剪切早期阶段同就位的花岗岩脉,后者为剪切稍晚阶段同就位的花岗岩。研究揭示出就位较晚的岩脉(即后者)因其位于递进剪切变形的高应变带而具有较为复杂的变形构造、显微构造和组构型式,就位较早的岩脉(前者)因在递进剪切变形作用过程中位于低应变带而具有简单的变形构造、显微构造和组构型式,并仍然保留有岩浆结晶组构特点。哀牢山-红河剪切带在28.54~27.31Ma间持续发生着从早期阶段较高温(~700℃),向中期阶段中高温(550~600℃)和晚期阶段低温(低于400℃)环境的递进剪切变形作用。 相似文献
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东南亚及哀牢山红河构造带构造演化的讨论 总被引：17，自引：1，他引：16
通过对东南亚和哀牢山红河构造带演化已有模式的分析,在近年来本区海上研究资料的了,结合滇西地质情况,认为东南亚的构造格局是由印度洋、太平洋和欧亚三大构造体系共同作用形成的。６０￣１５ＭａＢＰ,欧亚构造体系分别与太平洋和印度洋构造体系作用在东南亚东、西部形成两个弧后盆地扩张体系。两体系扩张强度和方向的不同,形成转换调节构造带－哀牢山红河构造带。东部较强的扩张作用使扬子板块向北运动,形成哀牢山以东的逆冲 相似文献
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滇西哀牢山构造带:结构与演化 总被引：19，自引：0，他引：19
哀牢山构造带是藏东(东南亚)地区的一条重要线性构造,它分隔了扬子—华南地块与印支地块,并保存了多阶段复杂大地构造演化的记录。哀牢山构造带内由东向西依次发育了晚太古代—新元古代深变质岩系、新生代构造-岩浆活动带(剪切带)、金平—沱江晚二叠—早三叠世裂谷带残余和哀牢山早石炭世—早三叠世混杂岩带。具有不同特点的地质单元间被以新生代为主发育的断裂构造所间隔;而不同时期异地就位或混合岩化成因的花岗质岩石在构造带中普遍存在。哀牢山构造带在不同地质历史阶段具有多重大地构造属性,总体上经历了3个重要大地构造演化阶段:前特提斯演化、特提斯演化和新生代陆内演化阶段。前特提斯演化时期,主体部分(尤其是其东部带)具有亲扬子地块的属性,保留了自晚太古代到新元古代地壳演化的记录。一直到早古生代时期,哀牢山构造带的大地构造属性与扬子—华南地区依然具有密切的亲缘关系。自晚古生代—早中生代时期古特提斯洋打开之后,该带与华南-扬子板块之间分化成2个属性不同的构造域,始于早石炭世打开的哀牢山洋与始于早二叠世打开的金平—沱江洋依次消亡。特提斯洋的闭合,一方面形成了古哀牢山造山带,同时使得扬子—华南地块与印支地块回复到一个统一的陆内环境中;印度—欧亚板块之间的交互作用,对这一地区有着深刻的影响,相继形成了早新生代哀牢山造山带、晚渐新世—早中新世造山后区域性伸展与高钾碱性岩浆活动性和晚渐新世—早中新世印支地块的大规模南东向逃逸、哀牢山大型左行走滑剪切作用及伴生的钙碱性岩浆活动性。 相似文献
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青藏高原东南边缘规模最大的一条新生代走滑剪切带沿云南滇西的哀牢山-点苍山山脉分布。构造和地貌证据表明,该山脉的形成可能经历了4个阶段:第1阶段发生在中新世早中期(22~17百万年),以差异性大规模的隆升为特征,同时伴随着剥蚀,成因是剪切带的左行走滑运动;第2 阶段发生在20~10百万年,以区域性侵蚀为特征,山体的大部分与周边地体同时被夷平;第3阶段发生在中新世中晚期(13~9百万年),以区域性隆升和河流快速下切为特征,差异性的侵蚀导致山体雏形的形成;第4阶段始于晚新生代(5百万年),以差异性隆升为特征,其中, 点苍山的隆升是构造成因, 而哀牢山山体的形成可能与红河的下切相辅相成,有限的隆升是地壳发生均衡反弹造成的。 相似文献
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构造非平稳运动定量研究的MDD模式制约 总被引：4，自引：0，他引：4
利用ＭＤＤ模式得到的连续冷曲线，可以定量地描述地质体的冷却（隆升）过程；采自我国７个不同地区中３８个钾长石ＭＤＤ模式研究结果证明，快速冷却事件存在的普遍性，不同的快速冷却速度可能反映了不同的构造事件；突变因子（δｖｉ）可以定量地描述地质体非平稳运动以及突变程度，并且使得不同地质事件非平稳程度的对比成为可能。 相似文献
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<正>The Ailao Shan-Red River fault zone is the boundary between the Yangtze block to the northeast and the Indochina block to the southwest.It is an important tectonic zone due to its role in the southeastward extrusion of the Indochina block during and subsequent to the Indian-Eurasian collision.Diancang Shan(DCS) high-grade metamorphic complex,located at the northwest extension along the Ailao Shan-Red River(ASRR) shear zone,is a representative metamorphic complex of the ASRR tectonic belt.Structural and microstructural analysis of sheared rocks in the high-grade metamorphic rocks reveals that they are coherent with solid-state high-temperature ductile deformation,which is attributed to left-lateral shearing along the ASRR shear zone.New LA-ICP-MS zircon U-Pb geochronological and microstructural studies of the post-kinematic granitic plutons provide a straightforward time constraint on the termination ductile left-lateral shearing and exhumation of the metamorphic massif in the ASRR shear zone.It is suggested that the left-lateral shearing along the ASRR shear zone ended at ca.21 Ma at relative lower-temperature or decreasing temperature conditions.During or after the emplacement of the young dikes at ca.21 Ma,rapid brittle deformation event occurred,which makes the DCS massif start fast uplift/exhumation and cooling to a shallow crustal level. 相似文献
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LIU Junlai TANG Yuan XIA Haoran GUO Qiang TRAN My Dung CAO Shuyun WU Hujun WU Wenbin ZHANG Zhaochong ZHAO Zhidan 《《地质学报》英文版》2010,84(6):1377-1390
<正>The Ailaoshan-Red River(ASRR) shear zone is one of the major Southeast Asian tectonic discontinuities that have figured the present tectonic framework of the eastern Tibet.Several metamorphic massifs are distributed linearly along the shear zone,e.g.Xuelongshan,Diancangshan, Ailaoshan and Day Nui Con Voi from north to south.They bear a lot of lines of evidence for the tectonic evolution of the eastern Tibetan at different crustal levels in different tectonic stages.Controversy still exists on the deformation structures,microstructures and their relationship with metamorphisms along the ASRR.In this paper detailed microstructural and EBSD(Electron Backscattered Diffraction) fabric analysis of some highly sheared granitic rocks from different massifs along the ASRR are conducted.High temperature structures and microstructures are preserved in unsheared gneisses,in weakly sheared xenoliths or in some parts of the highly sheared rocks(mylonites).Several types of high temperature quartz c-axis fabrics show symmetrical patterns or transitions from symmetrical to asymmetrical patterns.The former are attributed to coaxial deformation during regional shortening in an early stage of the Indian-Eurasian tectonic interaction and the latter are related to the transitions from coaxial compression to noncoaxial shearing during the post-collisional ASRR left lateral shearing. 相似文献
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琼东南盆地新生代发育机制的模拟研究 总被引：5，自引：0，他引：5
琼东南盆地是南海西北陆缘上一个北东走向的伸展裂陷带,向西与北西走向的莺歌海盆地相接,因此其构造演化包含了较多红河断裂走滑活动的信息。综合地质分析与物理模拟实验,我们发现琼东南盆地的发育既受控于南海北部陆缘的南东向—南南东向伸展作用,而且受到红河断裂左行走滑作用的控制和影响。其中,中央坳陷带主要受控于南东至南南东向的伸展作用;南部坳陷带的发育主要受控于琼东南盆地的伸展及其沿北北西向边界断裂右行走滑作用的构造叠加;而北部坳陷带的发育主要受控于北西向断裂左行走滑作用。红河断裂左行走滑作用可能开始于晚始新世,晚于琼东南盆地的伸展裂陷作用,且早期走滑速率应小于琼东南盆地的伸展速率,早渐新世(T70)以后红河断裂左行走滑速率大于琼东南盆地伸展速率,导致琼盆西段的褶皱反转,以及一组北西—北北西走向张剪断裂的发育。 相似文献
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西藏扎雪—门巴韧性剪切带变形时代及机制研究:来自同构造花岗岩体的证据 总被引：1，自引：0，他引：1
从同构造花岗岩体宏、微观变形特征入手,拟定出扎雪-门巴韧性剪切带内同构造花岗岩体的存在,并揭示出剪切带在空间上为一条近南北向逆冲推覆兼具左行走滑的斜冲型剪切带。同构造花岗岩体岩浆锆石LA-ICP-MSU-Pb年龄为(86.57±0.57)Ma,表明剪切带变形变质发生在晚白垩世,属冈底斯板块早、晚白垩世构造事件正反转后挤压体制下的初期产物。新特提斯闭合及洋壳俯冲所致的挤压构造环境导致晚白垩世冈底斯带普遍遭受区域变质作用,剪切带正是变形变质作用由南向北传递至该区减弱的表现,因此该变形年龄可能作为新特提斯闭合、洋壳俯冲作用延续到晚白垩世的年代学证据。 相似文献
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CENOZOIC LARGE-SCALE STRIKE-SLIP FAULT IN WEST YUNNAN, CHINA1 ZhongDalaiTapponnierP ,WuHaiwei,etal.Large scalesstrikeslipfault:themajorstructureofintracontinentaldeformationaftercollision[J] .ChineseScienceBulletin ,1990 ,35:77～ 97.
2 TapponnierP ,LacassinR ,LeloupPH ,etal.TheAilaoShan/RedRivermetamorphicbelt:tertiaryleft lateralshearbetweenIndochinaandSouthChina[J] .Nature,1990 ,343:4 31～ 4 37.
3 LiKang ,ZhongDalai.Themicrostructurecharacteristicso… 相似文献
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The Jinshajiang–Red River porphyry Cu–Mo metallogenic belt is an important Cenozoic porphyry Cu–Mo mineralization concentrating zone in the eastern Indo‐Asian collision zone. New zircon U–Pb and molybdenite Re–Os ages and compilation of previously published ages indicate that porphyry Cu–Mo deposits in the belt did not form at the same time, i.e., the porphyry emplacement and relevant Cu–Mo mineralization ages of the Ailaoshan–Red River ore belt in south range from 36.3 Ma to 34.6 Ma, and from 36.0 Ma to 33.9 Ma, respectively, which are obviously younger than the porphyry emplacement ages of 43.8–36.9 Ma and the relevant Cu–Mo mineralization ages of 41.6–35.8 Ma of the Yulong ore belt in north. Tectonic studies indicated that the Jinshajiang fault system in north and Ailaoshan–Red River fault system in south of the Jinsjiang–Red river belt had different strike-slip patterns and ages. The right-lateral strike-slip motion of the Jinshajiang fault system initiated at ca. 43 Ma with corresponding formation of the Yulong porphyry Cu–Mo system, whereas the left-lateral strike-slip motion of the Ailaoshan–Red River fault system initiated at ca. 36 Ma with corresponding formation of the Ailaoshan–Red River porphyry Cu–Mo system. Therefore, the different ages of porphyry Cu–Mo systems, between in north and south of the Jinshajiang–Red River belt, indicate that the porphyry Cu–Mo mineralization is closely related to the divergent strike-slip movements between the Jinshajiang and Ailaoshan–Red River strike-slip faulting resulted from the Indo‐Asian collision. The tanslithospheric Jinshajiang–Red River faulting caused partial melting of the enriched mantle sources of alkali-rich porphyries by depressurization or/and asthenospheric heating, and facilitated the migration of alkali-rich magmas and the corresponding formation of alkali-rich porphyries and relevant Cu–Mo deposits in the belt. 相似文献
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Pei-Ling Wang Ching-Hua Lo Ching-Ying Lan Sun-Lin Chung Tung-Yi Lee Tran Ngoc Nam Yuji Sano 《Journal of Asian Earth Sciences》2011,40(5):1044-1055
The PoSen complex, located closely adjacent to the southwestern margin of the Red River shear zone represents the uplifted basement of north Vietnam and may record the motion of the shear zone. However, its thermochronological history has not been fully examined yet. Here we applied U–Pb and 40Ar/39Ar dating methods to reveal its thermochronological history. U–Pb analysis of composite zircon grains by TIMS yielded an average age of 760 ± 25 Ma, clustering on the concordia line. Twelve SHRIMP U–Pb analyses also yielded a consistent result of 751 ± 7 Ma. Along with the geochemical features, the U–Pb dating results suggest the PoSen complex was a late Proterozoic magmatic complex, which could correspond to the Chengjiang orogeny, a widespread thermal event in southwest China. Results of 40Ar/39Ar dating of micas and K-feldspars were in the range of 36–30 Ma, revealing a rapid cooling and exhumation history of the PoSen complex during the late Paleogene. The time span of cooling and exhumation of the PoSen complex is slightly older than the main cooling phases of the Ailao Shan–Red River (ASRR) metamorphic massifs (28–17 Ma), but is synchronous with the early igneous activity stage in the eastern Indo-Asian collision zone of southeast China and north Vietnam. Owing to the ongoing debate about the initiation and offset of the ASRR shear zone, the tectonic force for the late Paleogene cooling of the PoSen complex is still inconclusive. The rapid exhumation of the PoSen complex could be in response to either the detachment of the Neo-Tethyan slab or a transpressional phase of continental subduction along the ASRR shear system in the eastern Indo-Asian collision zone. 相似文献
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CHARACTERISTICS AND METALLOGENIC EVOLUTION OF AILAOSHAN GOLD METALLOGENIC BELTS IN YUNNAN, CHINANNSFC(973Hi techProjects)andProjectofYunnanProvince ChineseAcademyofSciencescorporation(YK980 0 8 3) 相似文献
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The anisotropy of magnetic susceptibility (AMS) of 351 specimens from 51 sites across the Ailao Shan–Red River shear zone (ASRR) was measured to determine its magnetic fabric. Rocks range westward from core schistose gneiss, through low-grade schist, to Triassic sediment. Magnetic ellipticity analysis shows that 41 of 51 sites have an oblate compressional fabric and the other 10 sites have a prolate fabric. PJ value drops by 22.4% in the low-grade schist and by 27.4% in the Triassic sediment on average with respect to the gneiss, suggesting a rapid decrease of deformational intensity. The directions of principal susceptibilities are closely related to the deformation of the Ailao Shan–Red River shear zone. The susceptibility plane always coincides with the schistosity or cleavage plane. Most of the maximum susceptibility axes trend NW–SE. In the shear zone, the maximum susceptibility axes (Kmax) are parallel to the lineation within the foliation plane. With increasing distance from the shear zone, there is a trend that they become parallel to the down-dip of reverse faults or cleavage. This indicates changes in deformation mode, inside and outside the shear zone. Within the shear zone, horizontal movement is dominant. Outside, shortening prevails. The overall minimum magnetic axes align NE–SW with subhorizontal to low dip angles, suggesting that the dominant shortening is NE–SW directed. Caution should be exercised when AMS is used to determine shear sense in strong shear zones because the angle between the minimum susceptibility axis (Kmin) and pole of foliation is small, and also because the attitude of foliation varies from place to place. They result in unreliable or even wrong shear sense. Another important result is the axial ratio of magnetic susceptibility ellipsoid along the study section. With these data, it is possible to establish an axial ratio relationship between the finite strain ellipsoid and magnetic susceptibility ellipsoid for quantitative calculation of offset. 相似文献