A PRELIMINARY PROPOSAL ON CRUSTOBODY GEOTECTONICS

Geosyncline-platform geotectonics is aimed at the reconstruction of the Earth’s tectonic evo-lution history, and belongs to the category of historic geotectonics. Plate tectonics exp1ores pri-marily the motion of lithospheric blocks and belongs to the category of dynamic geotectoncis. Eachof them has its own advantages and strong points. However, both are difficult to meet the require-ments for an overall research on all-round tectonic problems- In order to make use of each one’sadvantages more effectively, an integrative, new type geotectonics called crustobody geotectonicsis here proposed. It is a branch of geotectonics which deals integratively with both evolution andmovement of the Earth’s crust by means of the concept of crustobody and the historic-dghamic in-tegrative analysis method.

A NEW INTERPRETATION OF THE EVOLUTION OF THE TETHYS CRUSTOBODY AND THE PETROLEUM POTENTIAL OF THE QINGHAI-XIZANG (TIBET) PLATEAU

Although large amounts of data have been collected during the past 30 yesrs in the study of the formation, evolution and dynamics of the Tethys Sea by the use of the theory of plate tectonics, a large volume of geological and geophysical information has also been accumulated which cannot be explained by the plate tectonic hypothesis. For example, the Qinghai-Xizang Plateau is underlain by many thousands of meters of Ordovician through Eocene, gently-dipping, essentially undeformed, stable platform sequences. Stratigraphic and tectonic investigations reveal that the plateau-wide east-west fracture zones, interpreted as "sutures" in a plate-tectonic model, are not sutures at all. On the other hand, from the Late Carboniferous to the beginning of the Early Permian, it was impossible for the Tethys ocean with a width of several thousand kilometers to."open" and "close" (the speed could not be so great). The east-west fracture zones, with very sharp angles, exerted no control over deposition. Stress analysis of magmatic activity indicates that the Himalayan zone is presently under compression, the Gangdise zone under interwoven comprepsion and tension, and the Qinghai and Deccan Plateaus under weak tension. Lateral compression caused by weak tension at the northern and southern terminations was not enough for Xizang and its surroundings between India and Qinghai Province of China with an area of 2,400,000 km2 to rise to a height of 4,000 m above mean sea level. The authors believe that surge tectonics is the force driving the evolution of the Tethys Sea and the rising of the Qinghai-Xizang Plateau. G. G. T. demonstrates that two surge channels, an upper and a lower, exist in the Yadong-Anduo litho sphere, and the upper mantle in the southern part is uplifted. During the Eocene, as a result of tectogenesis, molten magma poured out from the channel along the Yarlung Zangbo River,forming ophiolites and melanges, and earthquakes and terrestrial heat are also distributed along the fracture zone. Likewise, at an earlier time the Banggong Co-Nujiang and Longmu Co-Yushu Jinshajiang surge channels and their fracture zones formed. During the Miocene, the three surge channels merged laterally, and then the unified rise of the Qinghai-Xizang Plateau took place. The formation and evolution of the surge channels resulted in a variety of worthy Paleozoic, Mesozoic and Cenozoic exploration targets and a series of sedimentary basins with the largest Qamdo Basin occupying 120, 000 km2 with sediments attaining a thickness of 15, 000 m. These basins contain multiple source-beds, reservoirs, traps and seals of different ages, showing oil and gas every-where. In the northern part lithology and facies are more stable than in the southern, and subsequent tectonic overprinting and volcanic activity are relatively weak. At present commercial oil flow has been penetrated by drilling in the Tertiary Lunpola Basin.

Crustobody's movement and evolution and its relationship with Cu-Au mineralization of Eastern Tianshan, Xinjiang

Eastern Tianshan, a cardinal part of Northern Xinjiang compound continental crustoblock, is located in the east of Tianshan Diwa region. By analysis of regional geological and geophysical data, and by using crustobody theory and researching methods, this region can be divided into three sectors of different crustal structure. During Proterozoic to Eopaleozoic, the spreading and closing of Northern Tianshan Sea, on the foundation of disparate continental basements of each sectors, the transversal heterogeneity of tectonic movement and evolution resulted in the diversity of crustal structure and material formations. The metallogenic evolution indicated that different geotectonic evolution periods had not only different characteristics of mineralization commodity and mineral deposit types, but also the progressive mineralization feature. In Neopaleozoic, the closing of Northern Tianshan Sea from north to south and the difference of transmeridional tectonic deformation and magmation formed in the movement constituted the different metallogenic environment in shallow crust. Furthermore, it brought on the diverse Cu-Au-polymetal mineral deposit types and metallogenetic epoch from north to south and from west to east.

UNBALANCED SELF-ORGANIZATION THEORYAND CAUSES OF CRUSTOBODY EVOLUTION

It is generally cousidered that the mantle creep-flow eurtent is the most important internal cause for erustobody evolution. In fact, the Cause, mantle creep-now current takes place just beneath erustobody. Aeeording to the principle that internal causes of a tning determine its development and evolution, a special attetion should be paid to the basic causea of crustobody evolution. Vnder the guidance of the unbalanced self-organization theory, the authors elueidate that the crustobody system is a far-away thermal balaneed system and an open system, and thete are nonlinear interactions between the essentials, positive feedbacks and frequent fluetuation in the erustobody system. Finally, the following conelusions are drawn: the nonlinear interactions in the erustobody system are the basic formation (main internal cause) for erustobody evolution ; Substance and energy gained from surroundings are the basic conditions (main external cause) of crustobody evolution;and the fluctuations theide the erustobody system are the direct induetive cause of its evolution.

CRUSTOBODY STRUCTURE OF CHINA AND DISTRIBUTION OF ROCK GOLD ORE DEPOSITS

CRUSTOBODY STRUCTURE OFCHINA AND DISTRIBUTION OFROCK GOLD ORE DEPOSITSHuang Ruihua(Changsha Institute of Geotectonics, Academia Sinica, 410013, Hunan, China)rock gold ore deposit, crustobody structure, China.China continent is divided into four crustobodies from east to west. There is well-known Jinguashi rock gold deposit in East Asia continental margin crustobody. Gold met-allization is very well developed in East Asia crustobody. There are mainly rock gold ore de-posits related to Archean greenstone formation and Mesozoic-Cenozoic rock gold ore deposits in it. There are mainly Palaeozoic rock gold ore deposits of geosynclinal type and Cenozoic rock gold ore deposits of diwa (depression) type in Central Asia crustobody. South Asia crustobody possesses great potential in rock gold metallization. As a whole, prospecting exploration and exploitation of rock gold are very well of future in China.

Crustobody─A New Concept ofIntegrative Geotectonics

The crustobody is a concept of tectonic element established for integrating the research airns, objects and methods of historic and dynamic geotectonics in order to study the tectonics of the earth in an all-round way. It caTries the implications of both evolution and rnovernent, lying equal stress on both development viewpoint and connection viewpoint and giving consideration to both tirne and space. It has the nature, characteristics and functions of the above-mentioned two tectonic elements. On the one hand, though consisting of historic tectonic elernents such as geosynclinal, platform and geodepression (diwa) regions, it puts emphasis on their changing state in spatial rnigration, thus differing from them. On the other hand,though sirnilar in form to plate, a dynamic tectonic element, it places eruphasis on the changing state in its temporal evolution and has other distinguishing characteristics, thus differing from it.

A PRELIMINARY ANALYSIS OF TECTONIC STRESS AT VARIOUS DEPTHS IN THE SOUTH CHINA SEA CRUSTOBODY

Tectonic stress at various depths has been computed by means of the finite element method inthe South China Sea crustobody. The conclusion is that the distribution of the stress is: - 5. 1～3. 25 MPa (130 km), -5～2. 9 MPa (8O km), -5. 5～2- 15 MPa (3o km), -3. 6～0. 67 MPa (10km). and -2. 5～0. 11 MPa in the surface of crust. The interaction between tectonic stress andcrustobody movement in the South China Sea is preliminarily discussed.

EASTERN ASIA-WESTERN PACIFIC CRUSTOBODY AND TECTONICS

EASTERN ASIA-WESTERN PACIFIC CRUSTOBODY AND TECTONICSWei Zhoulin, Chen Guanghao - Fan Weiming, Lin Ge, Sun Shaohua, Pen Wenlan, Li Zhi’ an and Qin Qingxiang(Changsha Institute of Geotectonics, Academia Sinica, Changsha, 410013, China)Crustobody, evolution-movement, Eastern Asia-Western PacificThere’re 4 types of crustobodies and total 6.Each has its own way of evolu-tion and movement. Their combination and separation depict a complex history of geotectonics.

ACTIVATION (DIWA) STRUCTURES AND METALLOGENIC FEATURES OF THE CONTINENTAL-TYPE CRUSTOBODIES OF ASIA

Since the end of the Paleozoic, various crustobodies of the Asian continental lithosphere have successively undergone activation, resulting in the formation of widespread diwa-regime mobile belts. This is one of the important events in the evolution-movement history of the Asian continental lithosphere, occupies an important position in the problems of global tectonics and forms a frontier subject in modern geoscience. This paper, from an angle of crustobody geotectonics, discusses the following problems: formation time, distribution 1imits, types, development peculiarities and geotectonic significance of the diwa-regime tectonic element ; geochemical conditions of ore formation, principal mineral associations and ma jor deposit types in diwa structures of the Asian continent and their difference from those in other tectonic elements i and relationships between diwa-type metallogenesis and polygenetic compound and ultragiant ore deposits. Such a discussion can contribute to a better understanding of the tectonic types, distribution pattern and economic value of non-ferrous and rare meta1 endogenic ore deposits, peat, lignite and oil-gas fields.

REGIONAL ELEMENT ABUNDANCES OFCONTINENTAL CRUSTOBODIES IN CHINA

The continental crustobody of China is composed of three regional crustobodies, i. e., the Cathaysian crustobody, the West China crustobody and the South Tibet crustobody. This paper gives their mass models and element abundance values and discusses their regional abundance characteristics from metallogenic elernents, heat source elements and lanthanide elements. The conclusion is that their geochemical backgrounds are quite different from each other.

PRELIMINARY DISCUSSION ON METALLOGENESIS OF LANCANGJIANG RIVER TRANSITIONAL FIELD TECTONIC ZONE IN WESTERN YUNNAN

Applying the crustobody geotectonic theory to geological prospecting at the Lancangjiang river metallogenic belt in western Yunnan province, and on the basis of the basic geological background of western Yunnan and the space-time evolution-movement historical-dynamic features of the Lancangjiang river tectonic belt, the author has discussed firstly the metallogenesis of the Lancangjiang river transitional field tectonic zone, which can provide a new theoretical foundation for exploring the space-time laws of mineralization in this region.

Evolution-Motion of Crustobodies and Geotectonic Metallogeny

Following the paper entitled A Preliminary Proposal on Crustobody Geotectonics presented by the first author to the 30th IGC in 1996, this paper further extends and elucidates the concept of crustobody in order to make a unifying study of the evolution and motion of crustal structures and to understand the law governing the formation and development of the earth' crust. In this paper the characteristics of crustobody evolution-motion are given. The authors lay emphasis on the relationship between crustobody evolution-motion and tectonic metallogeny. In the end, a multiple dynamic system of the crustobody evolution-motion is discussed from internal and external dynamic forces, and the mantle creep in internal dynamic factors is paid special attention to.

A NEW UNDERSTANDING OF THE UPLIFT OF THE QINGHAI-XIZANG(TIBET)PLATEAU

The uplift of the QinghaiXizang(Tibet) Plateau happened indifferent crustal movements and different time from those of the collision of Asia continent with the allochthonous India crustobody, and the uplift occurred very long after the finish of the collision. According to its temporal evolution, the uplift happened in another active stage of the mantle creep flow after the active stage resulting in the collision and the interruption of the 140Ma′s quiet stage. On the basis of the dynamic analysis, the uplift resulted from the multiple compressing stresses in the reactivation stage after weakening of the colliding stress and the following compressing stress, and after the interruption of the stable stage dominating the vertical movements and represented by formation of the universal QinghaiXizang(Tibet) ancient platform. It was the production of another stress field existing in another crustobody evolution stage and growth age. In the light of the nature of the orogeny, the uplift was caused by the intracontinental Diwa (geodepression)type orogeny after converging connection of the Central Asia Crustobody and the India crustbody which immediately became a part of the Asia continent, and hence after the substitution for the colliding stress and the following compressing stress by the platformtype crustal movements.

THE EASTERN ASIA CONTINENTAL MARGIN EXTENSIONAL BELT

From an angle of integrative analysis on historical-dynamic geotectonics, the formation mechanism of the Eastern Asia continental-margin and historical background of the evolution-movement of the crustobody are discussed. The pull-breaking-extending and thinning of the continental margin crustobody in the region result in the formation of the continental-margin extensional belt.Finally, the theoretical and practical significance of the study is pointed out.

THE MECHANICAL RELATIONSHIP TO THE FORMATION AND DISTRIBUTION OF THEBURIED HILLS AND THE DEEP-SEATED FRACTURAL ZONE IN THE DIWA-TYPE FAULTED BASIN IN CENTRAL HEBEI PROVINCE,CHINA

The author proves the existence and movement of a deep-seated fraetural Zone located in the eenter zone of the diwa-type faulted basin in central Hebei Province. This deep-seated fraeturai zone tending in NNE direction is a structural effect of the mtodle East Asin Grustobody in the Mexozoic-Cenozoic. This paper will diseuss the formation, evolution and the meehanism of the deep-seated fraetural zone, faulted basin and the buried hills as well as their relationships. The uthor expounds that the deep geological process is the major factor of the structural effect.

PROSPECTING FOR COPPER (GOLD)-POLYMETAL ORES FROM THE LANCANGJIANG TECTONIC ZONE IN WESTERN YUNNAN

The L ancangjiang tectonic zone in Western Yunnan is an important magmatic,meta- morphic and tectonic mobile zone of Southwestern China,whose geotectonic location is very unique. It is characterized by complex geological structures,perfectly developed strata,fre- quent magmatic activities,various degrees of metamorphism,rich ore resources and lots of metal deposits,thus formed a centralized zone of mineralization and also constituted one of the importantmetallogenicbelts of noble and nonferrousmetal deposits.Thatiswhy the re- searching on geology for this zone is of great

EXTENSION OF THE CATHAYSIAN DIWA-TYPE OROGENSAND CONTINENTAL MARGIN SPREADING IN SOUTHEAST CHINA

EXTENSION OF THE CATHAYSIANDIWA-TYPE OROGENS ANDCONTINENTAL MARGIN SPREADINGIN SOUTHEAST CHINAZou Heping(Department of Geology, Zhongshan University, Guangzhou, 510275, China)late orogenic extension, Diwa, crustobody, continental-margin-spreading, Southeast China.A dynamic mechanism, "lower lithospheric delamination and extension of the Cathaysian Diwa-type orogens" , has been put forward to explain the formation of the Cenozoic continental-margin-spreading-belt in Southeast China. The processes of formation and develop-ment for the belt are from the stage of the Cathaysian Diwa-type orogens at which compression and thickening of curstobodies prevailed, to the stage of the basin-and-range-type structures at which the late orogenic crustal extension occurred, and then to the stage of the epicontinental Diwa-type rifts at which the lithospheric extension took place.

ON INTEGRATIVE GEOTECTONICS

ON INTEGRATIVE GEOTECTONICSChen Guoda(Changsha Institute of Geotectonics, Academia Sinica, 410003,Hunan, China)Xiang Jixi (The Chinese Academy of Geological Sciences, Beijing, China)integrative geotectonics, crustobody geotectonics,multi-origined and polygenetic compound resultantforce system, tectosphere, gradual change, mutation, catastrophismBased on historistic-causationist geotectonics proposed by Chen Guoda in1992, the authors attempt to further extend its contents and ranges, establish integrative geo-tectonics with wide ranges and higher synthesis. Integrative geotectonics is defined as a disci-pline to study very synthetically the whole history and causationistic relations of formation and evolution of the global tectonics (including the crustal and deep teetospheric structures) with the comprehensive analysis method. It is also called as "crustobody geotectonics" for its main geotectonic element is crustobody. Its characteristics are: (1) regarding the internal and exter-nal