新疆阿尔泰哈巴河一带古生代火山岩的形成与演化     

Zhang Chuanling 《地球科学与环境学报》1997,(1)

文中详细地论述了新疆阿尔泰哈巴河一带古生代火山岩的地质、岩石化学、稀土元素地球化学特征。将其分为三个类型，认为火山岩是在陆缘裂陷槽的区域构造背景下发生和演化的。对各类型火山岩岩浆来源，上升模式也做了初步讨论。  相似文献   

The stratigraphic framework for the Upper Pleistocene of the glaciated Russian Arctic: changing paradigms     

Valery Astakhov   《Global and Planetary Change》2001,31(1-4)

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北疆阿尔泰南缘泥盆系浅变质碎屑沉积岩地球化学特征及其形成环境   总被引：12，自引：4，他引：8  

龙晓平  袁超  孙敏  肖文交  林寿发  王毓婧  蔡克大 《岩石学报》2008,24(4)

对于北疆阿尔泰地区泥盆纪所处的大地构造环境,目前仍旧存在不同观点。前人基于阿尔泰南缘泥盆纪火山岩地球化学研究,分别提出了活动大陆边缘和被动大陆边缘裂谷等不同构造观点。阿尔泰造山带南缘的泥盆纪浅变质碎屑沉积岩地球化学研究表明,该套浅变质碎屑沉积岩原岩主要为泥质或砂质沉积岩。尽管不同岩性样品主量元素含量不同,但其化学蚀变指数(CIA)小于75,成分变异指数(ICV)接近或小于1.0,斜长石蚀变指数(PIA)平均70,说明其源区物质比较新鲜,成熟度相对较低,化学风化作用较弱。同样,不同岩性样品微量元素含量差别较大,但表生过程中不活泼的微量元素比值却比较一致,轻稀土(LREE)中度富集(La_N/Yb_N=2.88～9.90),重稀土(HREE)比较平坦,并伴有明显的Eu负异常(Eu/Eu~*= 0.45～0.89)。绝大多数样品具有高的La/Sc(1～3)、La/Y(0.5～1)和Ti/Zr(10～35),以及较低的Sc/Cr(0.1～0.3)比值,类似于大陆岛弧相关环境碎屑沉积物。在La-Th-Sc和Th-Sc-Zr/10构造环境判别图解中,除一千枚岩样品外,其他所有样品均落入大陆岛弧区。以上地球化学特征明显不同于大洋岛弧和被动陆缘沉积物,说明该套浅变质碎屑沉积岩可能沉积于活动大陆边缘的大陆岛弧相关环境,为认识阿尔泰造山带泥盆纪岛弧增生构造演化过程提供了一个重要证据。  相似文献   

Diversity and stages in evolution of conodontophorids and bivalve mollusks in Triassic seas of Siberia and the Far East     

T. V. Klets 《Stratigraphy and Geological Correlation》2006,14(2):174-184

Comparative analysis of taxonomic diversity dynamics of condontophorids from Boreal (Arctic regions of Russia) and Tethyan (Northwest Pacific) paleobasins showed that they had most favorable habitat environments in tropical seas. In the Boreal realm, condontophorids went through three stages of evolution comprising probably four substages and four phases, whereas three stages with six substages and twelve phases are distinguished in the Tethyan realm. The most important abiotic factors that controlled development of conodontophorids are paleotemperature of seawater and paleogeographic settings. Renewals in taxonomic composition conodontophorids and diversification of their assemblages have been confined to moments of paleotemperature and/or sea level rise. The comparative analysis of stages in evolution of conodontophorid and bivalve assemblages has been carried out. As is established, the peak taxonomic diversity of bivalves in Boreal seas was in the Late Triassic after the diversity minimum of the Early Triassic time. In contrast, conodontophorids were most diverse in the Olenekian Age.  相似文献   

Denudation and cooling of the Lake Teletskoye Region in the Altai Mountains (South Siberia) as revealed by apatite fission-track thermochronology     

Johan De Grave  Peter Van den haute 《Tectonophysics》2002,349(1-4)

Lake Teletskoye occupies a narrow graben located in the northwestern sector of the Altai fold belt in South Siberia. The lake basin is thought to have formed during the Pleistocene as a distant result of the Cenozoic collision of India and Eurasia that caused a tectonic reactivation of the Palaeozoic Gorny–Altai (GA) and West Sayan (WS) blocks.The present work reports of a pilot fission-track study performed on 13 apatite separates collected from rocks that were sampled along two profiles in close proximity of the lake. The age–length data and AFT thermochronological modelling reveal two important phases of cooling in the Altai Mountains, a first one during the Late Jurassic–Early Cretaceous and a second one that started in the Miocene–Pliocene and that persists until today. The first event is interpreted to result from uplift-induced denudation probably related to the closure of the Mongol–Okhotsk Ocean; the second event can be linked to the young Cenozoic movements that lie at the origin of the formation of the Lake Teletskoye basin.  相似文献   

Pseudotachylytes in the southern border fault of the Cenozoic intracontinental Teletsk basin (Altai, Russia)     

Karel Theunissen  Larisa Smirnova  Boris Dehandschutter   《Tectonophysics》2002,351(1-2)

The Cenozoic intracontinental Teletsk basin in the Central Asian Altai Mountains is composed of a complexly structured northern and a more simple southern sub-basin. These sub-basins formed in two distinct kinematic stages when first the NNW-striking Teletsk- and then the NE-striking West-Sayan shear zones became reactivated in the Cenozoic under dominant NS-oriented horizontal compression. Although the entire Teletsk basin strikes roughly NS, the southern sub-basin is parallel to the NNW-trending, amphibolite facies Teletsk ductile shear zone, while the northern sub-basin is NS-striking and flanked by differently structured, greenschist facies basement. Basement reactivation closely controlled the southern sub-basin formation, but this is less clear for the northern sub-basin. Contrasts between northern and southern basement and the exclusive occurrence of pseudotachylytes along the margins of the southern basin are explored for their contribution to the formation of the Teletsk basin with two distinct sub-basins.In the ductile shear fabric of the basement flanking the southern sub-basin, concordantly interleaved pseudotachylytes and isolated breccia lenses reflect local brittle deformation along the ductile fabric. The genetic link between breccia lenses and pseudotachylyte occurrences was defined by microstructural investigation. It allows to explore their possible development in a dextral strike–slip zone. These rocks occur in a large fault-bounded segment of the basement. The geometry of the structures in the segment is comparable with a dextral strike–slip sidewall-ripout structure along the Teletsk shear zone. Seismic slip related to pseudotachylytes is attributed to the sudden stress release on the NNW-striking Teletsk shear zone, when the latter became unconstrained by reactivation of the NE-trending West-Sayan fault zone at its northern boundary. The boundary of the sidewall-ripout structure was reactivated as a large listric fault in a later stage. The northern sub-basins roughly develop along an NS strike and are assumed to reflect reactivation of the ductile shear zone underneath the variably structured greenschist facies basement outcropping along the flanks of the sub-basin.  相似文献   

GEOCHEMICAL EFFECTS OF MAJOR ELEMENTS DURING FLUID-ROCKS INTERACTION IN MARINWOBO FAULT IN THE SOUTH MARGIN AREAS OF ALTAI MOUNTAINS     

ZHAO Zhi-zhong ZENG Qiao-song BI Hua 《大地构造与成矿学(英文版)》2002,(2):68-75

There are four types of metamorphic rocks in the Marinwobo fault, i. e, cataclasite, mylonite,mictosite and migmatitic granite, and the formation of these rocks is due to the progressive metamorphism of the pyroclastics. The fluids play a very important role in the metamorphic process of these rocks in the Marinwobo fault, the most important feature is that the fluids not only result in the migration of the major elements of the deformation rocks, but also result in the volume loss of the deformation rocks in the deformation process. Thus the migration laws of the major elements in different stages of the progressive metamorphic process are discussed according to mass balance equations. Finally, the quantitative analysis of the mass loss and volume loss of the different rocks the in Marinwobo fault is discussed in this paper.  相似文献   

STRESS-METAMORPHISM AND ISOTOPIC AGE OF SHEAR ZONE GRANITOID TECTONITES OF IRTYSH SHEAR ZONE (ALTAI REGION)   总被引：1，自引：0，他引：1  

B.M.Chikov  V.A.Ponomachuk  S.V.Zinoviev  B.N.Lapin  A.T.Titov  A.V.Travin  S.V.Palessky 《大地构造与成矿学(英文版)》2002,26(1):36-51

The Irtysh shear zone (ISZ) of Altai region is the lineament structure of the collision-suture type, where granites of Kalba complex and granodiorites of Zmeinogorsk complex are exposed to regional gneiss-formation and stress-metamorphic alterations. This study is based on detailed structural observations at special grounds using optical and electron microscopy, and on the behavior analysis of isotopic systems from altered granitoids.Within the ISZ area we have established the continuous rows of granitoid stress-metamorphism from initial recrystallization of protolite, its cataclasis and mechanical flaring up to complete recrystallization with alteration of mineral composition and formation of the streaky complexes of granite tectonites of blastomylonite and blastocataclasite types. The directed alteration of rocks has several impulse and is expressed by a change in morphology of mineral grains and their relations, magnification of deformation component in the rock structure, and formation of new mineral phases on the basis of initial ones without surface fluidization. At transformation of isotopic systems from granitoid, their feldspars,biotite and hornblende, we can observe “rejuvenation“ of the rock substrate from 270- 290 Ma for Kalba granitoids to 220-235 Ma for their tectonites, and for Rudny Altai granodiorites, their ages changes from 285-317 Ma to 232-257 Ma for their tectonites.  相似文献   

Engineering geology of loess and loess-like deposits: a commentary on the Russian literature     

I. F. Jefferson  D. Evstatiev  D. Karastanev  N. G. Mavlyanova  I. J. Smalley 《Engineering Geology》2003,68(3-4):333-351

Loess and loess-like deposits were much studied in the Soviet Union, and are currently under investigation in Russia and surrounding countries. There is a vast literature in Russian, which touches on all aspects of loess science and technology. In particular, the studies of the origin of collapsibility are almost totally in Russian, and of course studies on the various regions of Russia and the countries of the Former Soviet Union FSU appear in Russian. This review looks at the literature in Russian and attempts to pick out key contributors, major topics and works and to identify the critical regions and zones of investigation. Because so many regions of the FSU had people living on loess ground, there is a vast literature on engineering geology and ground engineering topics, and this tends to dominate all the literature on loess in Russian. Following Russian practice, the fine-grained deposits under consideration are divided into loess and loess-like deposits. Three main topics are recognised across the whole spectrum of loess research: formation and distribution of loess deposits; stratigraphy, cyclicity and palaeoclimatology; and engineering topics, in particular hydrocollapse and subsidence, and we concentrate on the engineering geology topics. An attempt is made, based on the map of Abelev and Abelev [Abelev, Yu.M., Abelev, M.Yu., 1968. Fundamentals of design and construction on collapsible macroporous soils, 2nd ed. Stroiizdat, Moscow, 431 pp. (in Russian)] of collapsing loess deposits, to define seven loess regions within the geographical limits of the old USSR. The seven regions are those where geotechnical problems might be expected.  相似文献   

俄罗斯远东金属矿床形成条件的古地球动力学分析   总被引：1，自引：0，他引：1  

А.И.汉丘克  阎鸿铨  张颖 《吉林大学学报(地球科学版)》2004,(Z1)

根据本区地质构造的新资料,提出了区域板块构造模型。研究了从俯冲到加利福尼亚型转换和由后者又到俯冲的古地球动力学环境更替的意义。这种更替发生在对本区最重要的中—新生代历史时期,对区域成矿带整体乃至一些金属矿床的形成具有重要影响。论证了一些地体性质,尤其是俯冲-增生杂岩对矿床形成的重要意义。  相似文献