中国青藏高原特提斯的形成与演化   总被引：4，自引：0，他引：4  

潘裕生  方爱民 《地质科学》2010,45(1)

青藏高原的形成是特提斯演化的结果。本文根据区域大地构造演化和沉积学证据,将青藏高原特提斯在时间上划分为3个阶段,即早期、中期和晚期。早期从震旦纪开始至奥陶—志留纪结束,这个阶段的大洋我们称作"原特提斯"。中期从泥盆纪开始至石炭—二叠纪结束,通常称这个大洋为"古特提斯"。晚期从二叠纪末、三叠纪初开始一直延续到第三纪早期,这个阶段的大洋通常被称作"新特提斯"。在空间上,青藏高原特提斯可以划分为3个区域相,即北区、中区和南区。上述3个阶段完全可以与空间上的3个区域相对应,原特提斯主要发育于北区,大洋消亡后的遗迹残留在青藏高原第5缝合带中,即西昆仑—阿尔金—北祁连缝合带。古特提斯主要发育于中区,大洋消亡后的遗迹残留在青藏高原第3、4缝合带中,即金沙江缝合带和昆仑南缘缝合带。新特提斯主要发育于南区,大洋主洋盆消亡后的遗迹残留在青藏高原第1缝合带中,即雅鲁藏布江缝合带,它的弧后盆地消亡后的遗迹残留在第2缝合带中,即班公湖—怒江缝合带。  相似文献   

LA-ICP-MS Zircon U-Pb Geochronology and Petrology of the Muchang Alkali Granite, Zhenkang County, Western Yunnan Province, China   总被引：4，自引：0，他引：4  

YE Lin  GAO Wei  CHENG Zengtao  YANG Yulong  TAO Yan 《《地质学报》英文版》2010,84(6):1488-1499

<正>The Muchang composite intrusion is located about 14 km southeast of the Fengwei town and south of the Baoshan-Zhenkang block.The rift-related intrusion consists of the early-stage riebeckite nordmarkite in the east and west sides and the discontinuous marginal zone,the late-stage main body of dominant riebeckite granite,and minor aegirine granite.Studies on petrological geochemistry and LA-ICP-MS zircon U-Pb dating of the late-stage riebeckite granite,origin and evolution of the Muchang alkali granite and the relationship between the granite and the associated skarn-type Luziyuan Pb-Zn deposit are discussed in this paper.The results show that the Muchang alkali granites belong to A-type granites,which are characterized by enrichment in Al_2O_3,SiO_2,total alkali and Fe, depletion in MgO and CaO contents with high FeO_T/MgO ratios.The REE concentrations are relatively high,exhibiting highly fractionated LREE patterns with significantly Eu negative anomaly. The Muchang granites are obviously enriched in lithophile elements(e.g.,Rb,K,U and Th) and high field strength elements(e.g.,Zr,Hf,Nb,Y and Ga) with high 10000×Ga/Al ratios and depleted in Sr, Ba,Ti,Cr and Ni,which are similar to those of the A-type granites and quite different from those of S-type andⅠ-type granites.The LA-ICP-MS zircon dating results of the Muchang granite gave a weighted mean age of 266.2±5.4 Ma(2σ),suggesting that they were formed in the stage of extension at the end of post-collision at Middle Permian and the consumption of Paleo-Tethys ocean took place before 266 Ma. It is suggested that the unexposed intermediate-acid intrusive rocks in the Luziyuan ore district,which is the "sister" rocks material of the Muchang granites and related closely to Luziyuan Pb-Zn mineralization,were the product of Middle Permian.  相似文献   

新型贴砾滤水管研制与应用     

卢豫北  吴烨 《河南国土资源》2001,(1)

利用高新技术研制的新型贴砾滤水管具有较高的强度和特点 ,它可广泛应用于水井工程和旧井处理工程中 ,不仅能提高生产效率、降低成本 ,而且还可彻底治理涌砂问题。  相似文献   

汉中地区含磷岩系对比与磷矿床成矿特征的讨论     

涂怀奎 《化工矿产地质》1997,19(4):239-243

汉中地区磷矿主要为早寒武世梅树村期及晚震旦世陡山沱期产物，以前者为主。矿床围绕古陆（特别是摩天岭和汉南古陆）边缘分布，为浅海 滨海相沉积产物。磷质物源主要来自古陆，而海底火山活动提供的Ｐ、Ｍｇ、Ｆ成为天台山磷矿形成的重要物源。摩天岭及汉南古陆边缘具有良好的找矿前景。  相似文献   

Preliminary report on Lower Jurassic radiolaria of Gondwana origin from the Kawhia coast, New Zealand     

R. S. Hori  Y. Aita  J. A. Grant-Mackie   《Island Arc》1996,5(2):104-113

Abstract Well-preserved radiolarians from the Newcastle Group in southwest Kawhia, New Zealand, constitute the first record of Lower Jurassic radiolarians from in situ deposits in high latitudes of the Southern Hemisphere on the margin of Gondwana. The radiolarians were extracted from carbonate nodules from five horizons in the Rewarewa Formation and the lower part of the Arawhero Formation, in the Murihiku Terrane. The radiolarian-bearing sequence, which lies within the upper part of the type section of the local Aratauran Stage, is roughly datable as Hettangian-Sinemurian from rare ammonite occurrences. The radiolarian assemblages consist, on average, of 80–90% spumellarians and 10–20% nassellarians. Spumellarians include species of the following genera: Archaeotriastrum, Crucella, Emiluvia (?) Homeoparo-riaella, Orbictilifomaa, Pantanellium, Paronaella (?), Pseudocrucella, PseIIdoheliodiscus, Spon-gostaurus and Spongotrochus. Nassellarians are composed of species of Ragotum, Bipedis, Droltus, Jams (?) Perispyridium (?) Raoultius, Riedelius, Saitoum and Thetis. From data of Lower Jurassic radiolarian faunas of Europe, North America and Japan, the New Zealand fauna shows stronger affinity with those of the European Tethys such as Turkey (e.g. De Wever 1982) and the Northern Alps (Kozur & Mostler 1990) than with faunas from other areas of the circum-Pacific. This connection between the European Tethyan and New Zealand faunas is not well explained by presently accepted continental reconstructions (Smith et al. 1994) for the Early Jurassic.  相似文献   

Gabbro-derived granulites from External liguride units (northern Apennine,Italy): implications for the rifting processes in the western Tethys     

M. Marroni  R. Tribuzio 《International Journal of Earth Sciences》1996,85(2):239-249

In Santonian-Early Campanian sedimentary melanges of the External Liguride units (northern Apennine), slide blocks of subcontinental mantle and MOR basalts are associated with lithologies derived from the continental crust. One of these sedimentary melanges, the Mt. Ragola complex, is characterized by the close association of mantle ultramafic, mafic and quartzo-feldspathic granulites. Mafic granulites show a wide compositional range. They generally display a marked metamorphic layering, but undeformed rocks which preserve a gabbroic fabric are found locally. The most frequent lithologies are Al-spinel gabbronorites, generally containing minor olivine, and Fe-Ti oxidebearing gabbronorites. Troctolites, olivine gabbronorites and anorthosites were also recovered. Relics of primary textures as well as mineral and bulk-rock compositional variations indicate a comagmatic intrusive origin for the protoliths of the mafic granulites. This intrusive mafic complex underwent a subsolidus reequilibration under granulite facies conditions, at 0.6–0.9 GPa and 810–920°C, and was derived from crystallization at intermediate levels of tholeiite-derived liquids, possibly affected by crustal contamination. Its primary features are similar to those of the upper zone of the Ivrea layered complex. The gabbroic protolith for the granulites of External Liguride units were probably crystallized into the extending Adria lithosphere in relation to the initial stages of the opening of the western Tethys.  相似文献   

康滇古陆东缘晚元古代—古生代层序地层     

刘怀仁  黄新兵 《四川地质学报》1996,(2)

根据沉积相的纵、横向变化，生物特征，陆上暴露标志，侵蚀痕迹，水下硬底，沉积层系的准层序叠复型式等，对康滇古陆东缘晚元古代—古生代地层层序进行了划分。  相似文献   

古新世特提斯北缘前黑海地区盆地的演化与油气远景   总被引：1，自引：0，他引：1  

B. M. 波诺托维奇  O. V. 萨马斯加  V. Yu. 塔柯维斯基 《沉积与特提斯地质》1997,17(4):40-49

本文以ＥＸＸＯＮ公司Ｐ．Ｒ．Ｖａｉｌ等人创立的层序地层学理论为准，对华南泥盆系的层序地层进行了区域上的研究、分析、对比。研究结果表明，从下泥盆统的洛赫科夫阶至上泥盆统的法门阶可识别出２０～２１个Ⅲ级层序。华南泥盆系的岩石地层、生物地层、年代地层的系、统、阶界线均已确定，与层序地层研究结果对比，生物地层界线均比相应的层序地层界线滞后。本文试图以层序地层序列为准，建立一新的地层系统作为相应的生物地层、年代地层的系、统、阶相对应的辅助性地层系统。研究结果表明，在岩石地层、生物地层、年代地层研究程度高的地区，可建立层序地层的系、统、阶界线系统以利于野外作业。华南地区的泥盆系内，除弗拉斯阶与法门阶的阶间界线置于饥饿层（ｓｔａｒｖｅｄｓｅｃｔｉｏｎ）外，其他的阶、统、系界线均位于有关阶（统）顶部层序中的ＨＳＴ的顶面。  相似文献   

桂西晚古生代海相玄武岩的特征及其形成环境   总被引：18，自引：4，他引：18  

王忠诚  邝国敦 《岩石学报》1997,13(2):260-265

广西西部广泛分布的基性岩，过去被认为是侵入的辉绿岩，晚古生代的基性熔岩只在泥盆系和下石炭统中零星分布，呈夹层产出，厚度不大。根据近年的野外工作，我们已经指出这些基性岩实际上是与晚古生代深水沉积共生的海相玄武岩，而不是象过去认为的大陆裂谷型玄武岩。玄武岩样品的地球化学分析结果表明，它们形成大洋板内构造背景，这证实了对古特提斯东延的设想，并有必要重新认识广西晚古生代地质演化的历史  相似文献   

东特提斯多弧一盆系统演化模式   总被引：11，自引：1，他引：10  

潘桂棠  陈智樑  李兴振  徐强  江新胜 《沉积与特提斯地质》1996,16(2):52-65

自70年代以来,以板块构造观点分析特提斯演化已有三种模式,即"剪刀张"、"传送带"和"手风琴运动与开合"模式。所有这些模式都是以一个联合古陆的形成和特提斯是泛大洋(古太平洋)中一个海湾的假设为前提,或以冈瓦纳大陆裂离、亚洲大陆增生为基点。随着对东特提斯(以青藏高原地区为主体)地质构造演化的认识深化,特提斯演化、造山作用的解释由两陆(劳亚和冈瓦纳)一洋(特提斯)模式转变为三陆群(劳亚、冈瓦纳、泛华夏)二洋(特提斯和古亚洲)的特提斯多弧-盆系统洋陆转换演化模式,即多岛弧造山模式。这一多岛孤造山模式源自大陆地质,尤其是在中国西部造山带、盆地长期的地质考察研究实践。
运用多岛弧造山模式,反思青藏高原及邻区山盆系统的地质事实,深刻认识到在东特提斯发现的许多由消减洋壳和消减杂岩所组成的蛇绿混杂岩带中,"三位一体"的蛇绿岩多数是"小洋盆"、弧后盆地、岛弧边缘海型,既存在早古生代岛弧、陆缘弧和晚古生代的火山孤,又有中生代的陆缘弧、岛弧。多岛弧-盆系统的存在意味着大洋岩石圈的存在、消减和转换。特提斯大洋岩石圈至少从古生代到中生代历经发生、发展到萎缩、消亡的长期连续的复杂的演化过程。古特提斯是原特提斯的继承和发展。中生代东特提斯也不是古特提斯洋消亡后重新打开,有部分特提斯洋壳可被随后的印度洋归并。
早古生代时,在泛华夏大陆群西侧已经出现昆仑前锋弧和康滇海岸山陆缘弧。昆仑北侧奥陶纪时的多岛弧-盆系统的形成,受原特提斯洋和古亚洲洋双重制约,类似于东南亚多岛弧-盆系受控于印度洋和太平洋双向俯冲。
从昆仑前锋弧和康滇陆缘弧裂离出的唐古拉-他念他翁残余弧构成泛华夏大陆西南缘的晚古生代前锋弧,羌塘-三江的晚古生代到中生代是弧后扩张、多岛弧-盆系统发育、弧-弧碰撞、弧-陆碰撞的演化史。
特提斯洋南侧的冈瓦纳大陆北缘,已有证据表明存在从石炭纪开始转化为活动大陆边缘的信息。中生代是西藏群岛的弧-盆演化史。
根据东特提斯时空结构单元的岩石组合和弧-盆系统共生规律,提出东特提斯演化多岛弧造山模式的假说,是阐明大洋岩石圈向大陆岩石圈构造体制转化的关键。我们相信多岛弧造山模式具有潜在的生命力。  相似文献