Abstract:Abstract: It is much more complex and difficult to study Archean stratigraphy than Phanerozoic stratigraphy. In studying Archean stratigraphy, we should make an integrated study of petrology, stratigraphy, structural geology and geological events, and, on that basis, use new techniques, especially those of geochronology. Furthermore, the following aspects should be emphasized: 1. make clear whether there are any complex isoclinal folds in nominal "monoclinic strata"; 2. determine correctly the types of rock and their attributes; 3. identify polyphase deformational overprints and how to correlate them with regional metamorphism; 4. understand the problems and pitfalls in geochronologic study; 5. clarify the nomenclature of the special units of rocks; 6. distinguish correctly the metavolcanic or sedimentary sequence and the possible structural contacts between the different units.

Abstract:Abstract: There have long been disputes about the age of the Wudang Group exposed in northwestern Hubei. This paper Reports the results of Sm? Juan Nd and Rb? Juan Sr dating of samples of metavolcanic Rocks of the the Wudang Group from North of Shiyan City, Taizipo of Wudang Mountain and Tucheng of in Fangxian County. The former Wudang Group consists of rocks of two parts of metavolcanic different ages. The protolith of one part of metavolcanic rocks originated at ~ 1972Ma and the materials of the volcanic rocks were derived from an area similar to the MORB mantle source area, During rock formatim no significant contamination with crustal material occarred; so they are the real Wudang Group . The age of the protolith of the other part is 1175-871Ma, similar to that of the protoliths of metavolcanic rocks of the Yaolinghe and Yunxi Groups, and their istopic compositions also show that this part of rock has an affinity to the latter. In the study of the stratigraphic age in an area with complex geological processes, good results may be obtained if we start with microscopic Nd isotope study.

Abstract:Abstract: The Liugouxia granitic gneiss is an old granitic intrusion divorced from the metamorphic complex of the Beidahe Group-complex found during 1:50000 regional survey of the Yu'erhong Sheet. Single-zircon U? Juan Pb dating yielded ages of 1463 ± 74Ma and 623 ± 138Ma. The two ages coupled with the results of regional survey suggest that the former age represents the age of emplacement of the old granitic intrusion, while the latter, the age of the deformational-metamorphic thermal event overprinted in the late stage. The two ages furnish direct evidence for the determination of the continental break-up and collisional orogeny in the early stage in the North Qilian Mountains.

Abstract:Abstract: The Mianlue suture zone is a typical ophiolitic-tectonic mélange belt. All the rocks have undergone strong deformation and metamorphism; so the composition of the belt is complex. The dominant tectonic style is marked by an imbricate structure characterized by overlapping of different thrust sheets with a series of north-dipping thrust faults as the framework. Study of its detailed composition and structure suggests that the suture zone is composed of continental-margin sedimentary sequences of different natures formed in different stages of formation and evolution of the oceanic basin, different types of ophiolite and tectonic blocks exposed in different modes during the subduction -collisional orogeny of the oceanic basin. Besides, regional stratigraphic correlation indicates that the formation of the Mianlue oceanic basin is characterized by east-directed "scissors-type" opening and propagation.

Abstract:Abstract: The Latest Permian-earliest Triassic Menggusi-Panyangshan-Ulan Haya nappe structure was found in the Ulan Haya area on the northern margin of the North China platform. The greenstone series of the Neo-archean Serteng Mountain Group-complex is thrust over the limestone of the Sinian Shinagan Formation and Paleozoic clastic series. The thrust surface strikes in a nearly E-W direction with an extension length of> 50km, the vergence of thrusting is 180-230 ° and the displacement is> 4.5km. Middle Triassic (U-Pb age 231Ma) monzogranite intrudes along the thrust surface and is in turn overlain unconformably by the Middle Jurassic Daqingshan Formation. The discovery of this nappe structure changes the previous view that no latest Paleozoic large-scale nappe structure exists in the area and has great significance in understanding the tectonic development and crustal evolution in the North China platform (plate). This implies that a large-scale intracontinental orogenic event occurred in the North China platform (plate) in the terminal Late Paleozoic and it is inferred that its dynamic source was derived from tremendous compressional stress produced by the collision between the North China plate and South China plate.

Abstract:Abstract: Studies of the contact relationships of the Chert Member of the Amugang Group with its overlying and underlying strata and fossils discovered in limestone pebbles and limestone intercalations, as well as comparative study of the data of radiolarian fossils in cherts at Caimarco and Rongma indicate that the Chert Member is not the crystalline basement but Triassic in age and can be correlated with the Late Triassic Gyiza Group.

Abstract:Abstract: In the paper the authors describe the features of a suite of clastic rocks and sedimentary-pyroclastic rocks and discuss the stratigraphic division and age assignment of the stratigraphic units on the north side of the Chengfang deep fault in the Daba Mountain area in the South Qinling. According to the lithological characteristics and contact relationships with the overlying and underlying strata, this suite is divided in descending order into the lower Sinian Muzhuo Formation and Dai'anhe Formation and the pre-Sinian Longtanhe Formation.

Abstract:Abstract: Late Precambrian strata are the first sedimentary cover on the early Precambrian folded metamorphic basement in North China. They are mainly distributed in some late Precambrian rift systems and aulacogens in North China, but the timing of deposition varies from area to area and the strata underwent more or less erosion in the late stage. Diverse views have long existed about the stratigraphic division and naming, use and age assignment of lithostratigraphic units. The divergence is even great in some areas. On the basis of the understanding of the geological characteristics of lithostratigraphic units, the author makes the stratigraphic correlation throughout the region and put forward unifying groups and formations, determines the features of representative lithostratigraphic units and rock associations that may serve as late Precambrian depositional sequences in North China, introduces the late Precambrian stromatolite assemblage and characteristic elements of the microflora, as well as mega-algae and metaphytes, and discusses the evidence for determining the chronostratigraphic division in the area where the stratotype is located and the age assignment of the chronostratigraphic units in various stratigraphic areas beyond the area of ??the stratotype.

Abstract:Abstract: There exists boundary claystone near the boundary between both the marine and terrestrial Permian and Triassic in the eastern Yunnan-western Guizhou area. This paper introduces the characteristics of the boundary terrestrial claystone in the area and discusses its origin. The principal minerals of the claystone are illite-montmorillonite mixed-layer minerals (20% -80%) and kaolinite (35% -80%), and the fragments include zircon, apatite, hexagonal dipyramidal high-temperature quartz and other types of quartz The And microspherules. It is suggested that the terrestrial boundary claystone in the area mainly formed by volcanism, accompanied by normal deposition and influence of impact.

Abstract:Abstract: Study shows that the Meso-and Neoproterozoic volcanic rocks distributed south of the line of Cele-Mingfeng-Yutian on the northern margin of the eastern segment of the West Kunlun Mountains, Xinjiang, consist dominantly of a suite of low-grade (basaltic ) andesite with very small amount of rhyolite. Andesite contains 52.36% -58.30% (mean54.55%) SiO2, <0.3% (mean0.22%) TiO2 and 1.70% -3.75% Na2O + K2O, with Na2O> K2O and Na2O / K2O = 2.44-4.61, M / F = 0.62-0.78 and MgO / (MgO + TFe) = 0.36-0.45. The alkali-silica composition shows that the rock is mainly calc-alkaline. REE study indicates that the ΣREE content of andesite is low, exhibiting a narrow range between 15.52 and 17.92 ppm, close to that of oceanic tholeiite. The (La / Yb) N of andesite is 0.69-1.33 and the (Ce / Yb) N is 0.75-1.17, the fractionation between HREE and HREE being not pronounced. Except for the δEu of sample 1028-13 that is 0.6, the δEu values ??of other samples are in the range of 0.91-1.17, basically no Eu anomaly being present. On the chondrite-normalized REE distribution patterns all the andesite forms a colony. The REE distribution patterns are close to that of oceanic tholeiite. Study of trace elements in andesite indicates the following: Th / Yb = 0.04-0.10, Th / Ta = 5.92-11.22, Zr / Hf = 20.46-29.40 and Th / Y = 0.04-0.08. The N-MORB distribution patterns of trace elements show that the rock is enriched in such large-ion lithophile elements as Sr, Ba, Rb, K and Th and depleted in Cr, as is similar to tholeiitic volcanic arc basalt. An integrated petrologic and geochemical analysis of the volcanic rocks, combined with the tectonic setting, suggests that this suite of volcanic rock occurred in an intra-oceanic arc environment.

Abstract:Abstract: The lithologic association of the Chuanlinggou Formation consists mainly of shales. According to the lithology and lithofacies association, vertical facies sequence and change in thickness, three areas may be distinguished: the northwest area, transitional area and southeast area. The lithologic association of the northwest area is composed mainly of mudstone with thin-bedded fine sandstone ,49-62m thick; that of the transitional area, mudstone and fine sandstone with two beds of medium-to coarse-grained sandstone varying in thickness from 60 to 240m, with a total thickness of 600m; that of the southeast area, mainly mudstone-shale,> 530m thick. Laterally they interfinger each other and their sedimentary environment belongs to the barrier island-lagoon system of microtidal coastal type (tidal range 0-2m).

Abstract:Abstract: Four types of isochronous or quasiisochronous boundaries, i. e. tactonic erosion urconformity, condensed surface overlopped by the local tectonic movement, facies transition surface and lake-flooding surface, are developed in the Paleogene and Neogene System on the Altun slope of the Qaidam basin. They may divide the Paleogene and Neogene lake basin-filling system into three tectonic sequences and four genetic sequences, and an isochronous stratigraphic framencrk and three sequence types, i. e. the initial rifting type, extensional rifting type and highstand type are established. Each sequence type is controlled by a specific sedimentary-paleotectonic setting and exhibits its own internal structure, thus forming the lake basin-filling model of continuous eastward migration of the depocenter of the Paleogene and Neogene Qaidam Lake basin and generaly upward-fining lake basin- filling.

Abstract:Abstract: The results of mapping by the structure-strata (rock)-event method indicate that the original Nyalam Group in the Gyirong area, southern Tibet, actually includes metamorphic strata and metamorphic plutonic rocks and should be integrated. The integrated metamorphic plutonic rocks are called the Sima gneiss, which was emplaced in the Jinningian Stage; whereas the metamorphic strata are called the Nyalam Group-complex, including the Quxam and Jiangdong Formation-complexes. They are in ductile fault contact with each other and were deposited in the Paleoproterozoic. Both underwent medium-pressure kyanite-staurolite subfacies regional dynamothermal metamorphism in the terminal Luliangian Stage and were subjected to amphibolite facies metamorphism in the terminal Jinningian Stage and greenstone facies retrograde metamorphism in the Himalayan Stage together with the Sima gneiss.

Abstract:Abstract: Four sea areas may be distinguished in China; they are the Bohai Sea, Yellow Sea, East China Sea and South China Sea. Muddy sediments are distributed as patches or bands along the continent of China in the four sea areas. Representative samples of muds were taken from their coasts and they were analyzed by XRF and ICP-Ms methods for K, Li, Rb, Sc, Mg, Ca, Sr, Ba, Al, Fe, Ti, Be, Nb, Ta, W , Sn, Bi, La, Ce and Th. The element geochemistry indicates that the geochemical characteristics of the muds along the coasts of the Bohai Sea and Yellow Sea, East China Sea and South China Sea are consistent with those of the sediments of the Yellow River, Yangtze River and Pearl River respectively, showing the material source effect of the elements. From the Bohai Sea to South China Sea, some elements in the coastal muds lose or are enriched more or less owing to the climatic change, showing the climatic effect of the elements. The element abundances in the muds along the coast of China are close to those in sediments in the continent of China but different from those of brown clays and abyssal clays in the western Pacific Ocean, showing the continental affinity of the elements.

Abstract:Abstract: Through multi-target geochemical survey advances have been made in the study of the background values ??and distribution characteristics of the elements, study of structure, agriculture and environmental pollution, prediction of natural gas and calculation of the pH values. It is judged that the deep-layer samples play a special role in the study of the distribution of deep-seated elements, structure, development of root-deep crops and prediction of natural gas and that the shallow-layer samples plays a special role in the study of the distribution of shallow-seated elements, agricultural geology and environmental pollution. The multi-target geochemical survey and double-layer sampling can be popularized.

Abstract:Abstract: On the basis of the tectonic units, tectonic evolution and deposit association, the Qinling orogenic belt is divided into four mineralization concentration areas: the Xiao Qinling craton activation area, Xiong'ershan rift accretion area, South Qinling passive continental-margin down- faulted area and Bikou terrane paleo-assemblage zone, which separately form four minerogenetic series: the granite-greenstone belt-type gold-iron minerogenetic series, continental volcanic-hosted gold-molybdenum minerogenetic series, sedimentary-hosted gold-lead-zinc-mercury -antimony minerogenetic series and marine volcanic-hosted gold-silver polymetallic and ultrabasic-hosted nickel-gold minerogenetic series. Syngenetic mineralization is related to extensive mantle or hot spot activities in the early stage (Paleozoic and its preceding stage) of format of the orogenic belt; post-genetic mineralization was accomplished during the basin-range transformation and intracontinental tectono-magmatic activities (at 120 -340mA).

Abstract:Abstract: The Jiama-Qulong ore concentration area, Tibet, 124km long and 69 km wide, is located in the east-central part of the Mid-Late Jurassic-Paleogene Gangdise continental-margin volcanic-magma arc. Through recent geological survey, mineral exploration and ore deposit study, the authors found several ore concentration areas in the Gangdise continental-margin volcanic-magma arc, of which the Jiama-Qulong ore concentration area is one of the important copper polymetallic ore concentration areas in the arc. The deposits of this area are represented by the large Jiama-Qulong copper polymetallic ore deposit which is being exploited. In addition, they also found a number of very promising deposits and mineralization occurrences such as Oulong South, Oulong North, Dirima, Songduoxiong, Lakang'e and Xiangbeishan. They are characterized by unique mineralization types and a variety of genetic types, suggesting that they are products of different stages of evolution of the Gangdise continental-margin volcanic-magma arc. These different types of deposit are concentrated in a certain areal extent and have primarily shown and formed an important ore concentration area with great ore potential and a certain ore prospect in the Gangdise continental-margin volcanic-magma arc. The authors believe that through further work this area is expected to become another nonferrous mineral resource base in western China.

Abstract:Abstract: Several types of volcanics-related gold deposits are found in the Tulasu basin of the West Tianshan. According to their mineralization features, ore-controlling factors and geological environment, three basic types may be distinguished: low-sulfur epithermal type, porphyry type and stratabound epithermally modified type. They are an association of gold deposits formed in the same tectonic setting and in a unifying hydrothermal fluid field, i. e. the Axi type gold minerogenetic series. Secondary fluid fields and specific tectonic environments determined the certain regularities: the low-sulfur epithermal type formed in the Early Carboniferous and occurs in marginal faults of volcanic edifices; the porphyry and stratabound epithermally modified types formed in the Middle-Late Carboniferous and occur respectively in the fracture systems inside acid porphyries and their margins and in the Second Member of the Dahalajun Formation.

Abstract:Abstract: The 1:500000 geological map database of China was developed with the China-made software MAPGIS 5.0 as the basic platform and the appended maps (1:500000) of regional geology of all the provinces, autonomous regions and municipalities and the 1:200000 geological map of the Hong Kong Special Administrative Region as the basic data. The geological map was compiled by using new theories and ideas on modern geology, stratigraphy and petrology and new methods of presentation and according to the lithostratigraphic units, hierarchical units of granites and time plus lithology for intrusive rocks. The database was composed of the digital geological map database and geographic base map database. The retrieval can be made arbitrarily according to any space scope, different scales, different projection methods and different geological and geographic content, and one can retrieve one item or multiple items. Through retrieval a complete geological map with the legend and ornaments is produced automatically.

Abstract:Abstract: Digital regional geological survey is a problem that needs urgent solution in the main informatization course in geological survey and mapping. Based on the present state of the digital field geological survey and digital mapping techniques and mapping data capturing techniques in developed countries, coupled with the actual conditions of China, the authors discuss the field geological survey and mapping digital data capturing techniques, data model, technical flow chart and tools and methods of applying digital mapping techniques for the purposes of changing the conventional mapping means, raising the research accuracy and degree, accelerating the cycle of research work and changing the form of presentation of the research results.

Abstract:Abstract: Pre-Sinian low-grade metamorphic rocks in South China are a special rock type, which is different from not only medium-and high-grade metamorphic rocks but also sedimentary rocks. Because of its particularity and lacking of a mapping method specially for them, there are a number of prominent problems in displaying the available results of regional survey, e. g. there is much difference between the presentation of the map and words and the temporal-spatial distribution of geologic bodies. Through an analysis of major problems and practice and checking of several related projects, the authors have preliminarily summed up a mapping method, i. e. proceeding from an analysis of an area, first establish a lithologic maker bed and structural style of the area, and then take the marker bed and structural style as the core and extrapolate and extend them to other areas; on the basis of gaining knowledge and checking the results repeatedly, establish mapping units and perfect and finalize the structural style and structure of the map surface

Abstract:Abstract: Luoji Mountain, where ancient glacier remains are developed, is an important scenic spot in southwestern Sichuan. The touriam resources of an area centered on Luoji Mountain is characterized by high integration, a great variety, a high rank and complete functions. From the tourism resources, geographic location and social environment, this paper systematically analyzes the advantageous conditions and constraints for the development of Luoji Mountain, discusses the value and feasibility of its development and puts forward the concept of its development strategy.