Abstract:Abstract: In the Sinian (680 Ma), the Sino-Korean plate began to break up into two different tectonic units, the Jiao-Liao-Korea block (JLKB) and North China block (NCB). The boundary of the two blocks is called the Paleo-Tanlu fault (PTLF). The position of this fault is coincident with he present Tanlu fault, which extends from Hefei northward via the Bohai Sea to east of Shenyang and then turns NE and goes to southern Jilin. Strong earthquake records in Sinian carbonate rocks in the vicinity of the PTLF and corresponding diabase emplacement are basic geological evidence for the intraplate break-up of the Sino-Korean plate. The break-up period of the PTLF (intraplate seismic zone) is consistent with that of Proterozoic Rodinia. Archean basement rocks in the two blocks are different and the Proterozoic and Paleozoic histories of the two blocks on the eastern and western sides of the PTLE are different. The two blocks were again amalgamated in the Late Carboniferous Moscovian stage. The Rimjin River zone on the central Korea Peninsula was considered the eastward extension of the Dabie-Jiaonan orogenic belt. However, the Rimjin River zone is only an ordinary fault and China's Jiaonan ultrahigh-pressure belt bas not been found on the Korea Peninsula. Considering the similarity in the Paleozoic between the southern main area of ??the Korea Peninsula and the Liaodong Peninsula, the southern boundary of the Sino-Korean plate, i. e. the southern boundary of the JLKB is placed on Jizhou Island south of the Korea Peninsula in the paper. It joins the Jiaonan orogenic belt with the presumed Yellow Sea transform fault. Diamondiferous kimberlites in Wafangdian (originally called Fuxian County) of Liaoning Province and Mengyin of Shandong Province are distributed on the eastern and western sides of the Tanlu fault over a longitudinal distance of ~ 550km. The age of the kimberlites in the two areas ranges from 500 to 450Ma, i. e. the rock was emplaced at the end of the Middle Ordovician. Since the kimberlites in the two areas have similarities in some aspects such as petrography, mineralogy and emplacement age and are both close to the Tanlu fault, some geologists think that the kimberlites of the two areas were possibly very close to each other during their emplacement and belong to the same province; therefore they always explain the distance letween the Wafangdian and Mengyin kimlerlite provinces with the great displacement of the Tanlu fault. The Tanlu fault is a deep fault cutting through the lithosphere. Comparison of the differences and similarities between the lithosphere profiles of Wafangdian and Mengyin provides significant evidence for judging whether the Tanlu fault has a great displacement. Study of the mantle samples in the kimberlites reveals that the profiles of the paleo-lithosphere that the kimberlites in the two areas cut through during their emplacement are very different. This indicates that the two areas are neither contiguous nor close to each other at that time. On the basis of the above-mentioned sample study, combined with the new understanding got from a study of the regional geological structure, the authors find that the two kimberlites were actually emplaced separately into two different tectonic units of the Sino-Korean plate and the distance between the two areas is independent of displacement. This finding does not support the view of the great displacement caused by the Tanlu fault.

Abstract:Abstract: The last-phase and strongest uplift of the Qinghai-Tibet plateau occurred at 1-0.8Ma BP, which was related to the Australasian meteorite impact event in the triple junction of the Indian Ocean ridge. The impact event resulted in rapid spreading of the Indian Ocean ridge and strong A-subduction of the Indian plate beneath the Siwalik. The strong subduction gave rise to the rapid uplift of the Qinghai-Tibet Plateau and its surrounding mountains, thus forming the basin-range geomorphology in western China. The eastern Kunlun Mountains were elevated approximately 3000 m by the thrust system and meanwhile moved ~ 400km to the north, which should be responsible for the Cenozoic deformation in the Qaidam basin and Hexi corridor. Therefore, this impact event can interpret the last phase of the uplift of the Qinghai-Tibet Plateau and geodynamic background of the formation of continental tectonics of western China. 40Ar/39Ar dating of neogenic minerals during deformation suggests that the strike-slip movement of the Altun (Altyn) fault may have started at 97-89Ma, occurring nearly synchronously with the formation of the "Western tectonic node" in the Nepal-western Kunlun area The Altun strike-slip fault has a cumulative offset of 350-400km and displaced the original tectonic belts and basins in the Late Cretaceous-Cenozoic, which provides a new idea for mineral, oil and natural gas searching in western China.

Abstract:Abstract: A typical bimodal volcanic rock association, composed of basalt and rhyolitic volcanic rocks, is distributed in the Mesozoic Linjiang volcanic-sedimentary basin, which is located in the eastern segment of the Nanling tectono-magmatic belt and controlled by the Sannan-Xunwu fault belt. The Rb-Sr isochron ages of the basic end-member (basalt) and acid end-member (rhyolite) of the bimodal association in the Changpu Formation of the Yutian Group in the Linjiang area are 173.7 ± 2.5 Ma and 174 .9 ± 3.9 Ma respectively. Thus it is ascertained that the bimodal volcanic rock association is of Middle Jurassic age. This provides convincing isotope age evidence for the extension and break-up of the eastern segment of the Nanling during the Early Yanshanian.

Abstract:Abstract: The 40Ar/39Ar age of crossite in blueschist in the Shuanghu area, Tibet, but the age of the protolith of the blueschist is highly controversial. Previously most researchers think that the protolith is earlier than Devonian in age and some researchers even think it to be Meso-and Neoproterozoic in age and call it the Amugang Group. On the basis of 1:100000 mapping and measurements of the section, the authors collected relevant samples and obtained the Sm-Nd isochron ages of 272 ± 7Ma, 268 ± 5.6Ma and 252 ± 4.6Ma for the protolith of the blueschist. On that basis, combined with the regional geological conditions and occurrence of blueschist in the Shuanghu area, it is believed that the age of the protolith of the blueschist is Permian, and the age of the Amugang Group is assigned to Permian and the age of the Qiagelela ophiolite is determined to be late Early Permian. The age dating provides important evidence for the evidence of the Paleo-Tethys in Lungmu Co-Shuanghu.

Abstract:Abstract: According to the geological survey of 1:50000 Shimenchuan Sheet and Laolongwan Sheet, volcanic rocks different from those in the Early Ordovician Yingou Goup have been found in the Shandiaodiaopo area, Jingtai County in the eastern segment of the North Qilian Mountains. Sm-Nd isochron dating of the volcanic rocks shows that they formed during the Neoproterozoic, about 723 million years ago. REE and trace element and trace element geochemical characteristics suggest that a compressional environment resulting from subduction of oceanic crust occurred there at that time.

Abstract:Abstract: A compositional evolutionary series of Late Ordovician granite bodies is developed in the vicinity of the Xiaoshanhe Tree Farm in the Yichun area, Heilongjiang Province. Through systematic 1:50000 regional survey, the series has been studied and classified in detail and the hierarchical mapping units of the Beiying Tree Farm have been established. Dioritic inclusions are common in fine-to medium-grained, porphyritic hornblende-bearing biotite monzogranite of the Xiaoshanhe unit. Most of these inclusions occur as elliptical grains of varying size at the edges of the granite intrusions. Intensive petrological, mineralogical and rock geochemical studies of the granitic rocks and dioritic inclusions indicate that the rocks and inclusions are genetically related and have an affinity in evolution. The dioritic inclusions are immiscible ones and resulted from the evolution of the felsic magma during its liquation.

Abstract:Abstract: On the basis of several field geological surveys and voluminous regional geological data, the authors propose that the westward extension of the southern "Inner Mongolian axis" marginal fault belt is the Linhe-Jining fault. Aeromagnetic and gravity data show that this fault belt has pronounced anomalies and the Moho depth contour data show that it is a deep fault belt whose influence reaches the mantle. Additionally, this fault belt is also a long-lived one, which was active in different forms in the Mesoproterozoic, Paleozoic, Mesozoic and Cenozoic respectively. This systematically summarizes the characteristics of the activities of the fault belt in different ages and first analyzes multiple types of fault structure formed in its long-continued activities.

Abstract:Abstract: Based on an analysis of the data obtained from 50000 km of integrated geophysical profiles and relevant geological materials, layer-blocks of different orders have been distinguished within the Nansha microplate; they are the Nansha ultra-crustal layer-block, Zengmu crustal layer -block, Nanwei-Andu and Liyue-North Balawan crustal layer-block, Bisheng-Andu and Liyue-Banyue basement layer-block. The basic characteristics of these layer-blocks are discussed. The concept of "cross-deck bridge-like" movement of layer-block tectonics is proposed. In light of the view of the multi-geodynamic origin, the formation mechanism and main driving forces of these layer-blocks are probed. The subducted slab delaminating-mantle upwarping force, mantle flow drawing force, inertial force of earth rotation and regional plate boundary force are considered as the main forces driving the ultra-crust layer-block, and the gravity instability force and intracrustal rheological-plastic layer uplift force are considered as the forces driving the crust layer-blocks and basement layer-blocks.

Abstract:Abstract: According to an integrated study of the data of regional survey of the 1:50000 Xingan Map Series in the Xiajiang area, central Jiangxi, the authors for the first time propose the view that the Devonian strata in the area are an allochthon and hold that the Devonian was thrust from NW to SE in the late Indosinian to early Yanshanian and then again underwent extension and detachment to the SE in the late Yanshanian stage. There are many reports about the existence of thrust nappe and sliding nappe structures in northern and southern Jiangxi but few reports have been read that they exist in central Jiangxi. The discovery and determination of thrust nappe and sliding nappe structures in the Xiajiang area this time have great tectonic significance for the understanding the relation of the NNE-trending thrust nappe and sliding nappe structures between southern and northern Jiangxi and even the understanding of the whole. This paper mainly deals with the characteristics of the thrust nappe and sliding nappe structures with detailed field first-hand data and preliminarily analyzes their genetic mechanism.

Abstract:Abstract: By using the method of tectonic slab mapping in the continental orogenic belt, the authors carried out a systematic study of the Tazang tectonic belt of Jiuzhaigou. It is considered that the Tazang tectonic belt is a tectonic mélange belt with distinct northern and southern boundary faults. Its northern boundary is the Yazagou fault striking NW-SE, and the southern boundary is the Heye fault, which also strikes NW-SE. The Tazang tectonic belt extends in a NW-SE direction for as long as ca. 16-24 km with a width of 7-8 km and is composed of three Late Paleozoic and Triassic tectonic slabs (or blocks) of varying sizes and shapes and in faulted contact with sandy slate of the Tazang complex. Generally, there is no order between the slabs and there is order within the slabs. Microscopic deformation features are conspicuous and the three-dimensional finite strain measurements show compression in NE-SW and nearly S-N directions. Analysis of the tectonic environment of the survey area shows that there occurred four phases of deformation.

Abstract:Abstract: Regionally located in the central segment of the Shangyi-Pingquan fault belt, the Gubeikou thrust nappe structure is the product of the Yanshanian intraplate orogenic movement. It is developed on the northern side of the Mesozoic down-faulted basin. Controlled by two major faults, the upper and lower nappes were successively thrust from north to south. The autochthonous system consists of the Mesozoic Tuchengzi Formation and the strata below it. K-Ar dating of samples from a syntectonic quartz syericte dike in the fault zone yielded an isotope age of 16.1 ± 2.3Ma; so it is considered that the thrust nappe structure in the area formed between the Middle Jurassic and Late Jurassic. A brittle-ductile deformation belt is formed locally in the Mesozoic strata.

Abstract:Abstract: The Langgu subdepression is a majou oil-producing area in the North China oil field. On the basis of the hole core data combined with the seismic data and by using the basic principles of sequence stratigraphy and seismic stratigraphy, the authors studied the Paleogene in the subdepression, distinguished depositional sequences, revealed the tectonic framework of sequence stratigraphy and probed into the characteristics of the regional depositional framework and their controlling effects on petroleum generation and accumulation.

Abstract:Abstract: The Youngest marine strata are exposed in the Gamba-Tingri area, southern Tibet. The study of this succession of marine strata may provide good information about the late evolutional history and closing age of the Tibet-Tethys remnant sea. On the basis of detailed fieldwork and laboratory thin-section identification, the authors studied the fossil carbonate microfacies of the Eocene Zhepure Formation in the Gamba-Tingri area. Ten types of microfacies (MF1-MF10) and five types of biofacies are recognized. The genetic mechanism of conglomeratic limestone of the Zhepure Formation is also discussed in this paper. It is suggested that the conglomeratic limestone formed completely by contour current sediments on the platform-margin marine slope, rather than by redistribution of materials. Based on the above study, a detailed analysis is made on the late phase of the sedimentary evolution of Tibet-Tethys. The authors consider that a transgression took place in the Gamba-Tingri basin during the Eocene Ypresian-early Lutetian. In the late Lutetian, the Gamba-Tingri area was generally in a regressive environment. At that time, however, the Gamba area became a restricted deep-water depression as a consequence of continental compression due to plate collision. In the early Priabonian seawater completely withdrew from this area.

Abstract:Abstract: Located in the Naiman Banner and southern Hure Banner, Inner Mongolia, the study area tectonically belongs to the Tianshan-Chifeng mobile belt on the northern margin of the North China plate. The Late Carboniferous strata in the area consist dominantly of terrestrial clastic rocks and carbonate rocks, which have a facies change relation in space. According to the microfacies assemblage or essential sequence, sedimentary structures, biological features and their spatial distribution characteristics, four facies, namely littoral facies, tidal-flat facies, back-platform basin facies and platform facies, and eight microfacies may be distinguished; they form a relatively complete transgressive sequence, belonging to deposits of the transgressive systems tract. This suggests that the Late Carbonate sea trough on the northern margin of the North China plate is a passive terrestrial basin, i. e. the epicontinental environment.

Abstract:Abstract: Rock body-type tin deposits in Dayishan, Hunan, occur in the Late Jurassic Jietou unit of the Tangshipu super-unit. The ore is slightly below the medium grade and easy to dress. The deposits are large in size and formed in a restricted environment, showing vertical zoning. Regional structures, magmatic rocks, country rocks and restricted environment jointly control the occurrence and size of the rock body-type tin deposits. In this paper the genesis of the rock body-type tin deposits is analyzed. As the magma is differentiated and evolved in a restricted environment, ore-forming elements are unevenly distributed, causing the intrusion of the Jietou unit to be rich in W and Sn and an ideal metallogenic model of rock body-type tin deposits is formed in the front or uparching portion of the intrusion. From above downward the rock body-type tin deposits show the characteristics of vertical zoning of alteration and mineralization from high to low temperatures.

Abstract:Abstract: The position of the remote sensing technique in ore deposit prediction has become more stable because its unique spatial and spectral characteristics. It can predict favorable areas for occurrence of ore deposits from the macroscopic angle and multiple aspects. As a new geological theory, geological anomalies can make scores of various favorable ore-forming geological conditions by means of the quantitative statistical analysis. The geological anomaly field is an integrated anomaly field and an integrated reflection of various ore-forming geological factors. The integrated evaluation of geological anomalies lays more emphasis on the microscopic and local analysis. On the basis of the advantages and limitations of the remote sensing technique and geological anomaly theory themselves, the authors combine remote sensing with geological anomalies to make an integrated evaluation of ore-forming favorable areas in the Lanping basin.

Abstract:Abstract: According to the results of magnetotelluric sounding of the Huapi-Zhaizhangzi profile in northern Hebei, the variation patterns of the strata with different electric characters have been distinguished along the profile, the basement relief form determined and the location of fault distribution inferred. Along the profile there are three local buried structures, namely, the Puhe structure, Tazishan structure and Zhaizhangzi structure, of which the Puhe and Zhaizhangzi structures have petroleum prospects. The Tanba-Xiaoxigou fault and Shuangdong South fault are structurally controlling faults, which divide the profile into three down-faulted areas; the Beidian-Taitoushan fault is a large west-dipping reverse fault; the Changzhougou Formation is thrust over the Wumishan Formation, with a displacement of nearly 4000m.

Abstract:Abstract: According to the results of TM remote sensing image interpretation of two time phases in 1987 and 1999 and using the space analysis and mathematic statistics of the geographic information system, the paper analyzes the degree of land desertization and features of the temporal-spatial change of land desertization in the Yulin area, northern Shaanbei, in 1987-1999 and discusses the cause of land desertization. The analytic results indicate that since the late 1980s the process of the land desertization of the area as a whole has tended to be stable and taken a more or less favorable turn. This mainly benefits from the policies of active and effective control of land desertization implemented by the local government. The fragile ecological environment, arid climate and plenty of wind are main natural driving factors for land desertization, while irrational human activities are a factor of inducing land desertization. Measures of active control and improvement can effectively control the process of desertization.

Abstract:Abstract: On the basis of the analysis of sporopollen from well CK1, the authors studied the events of climatic fluctuations of 10 ka and 1 ka scales since 150 ka BP and obtained the climatic change cycles from the sporopollen records of sediments in the Yinchuan basin by the frequency spectrum analysis. The study indicates that the climatic cyclic fluctuations of the 10 ka scale may be correlated with the variations of the Earth's orbital elements in the Milankovitch theory in the high-latitude areas, while the quasi-cycle of the 1 ka scale corresponds to D / O. This suggests that there exist climatic fluctuation events of 10 ka and 1 ka scales in the Yinchuan basin.

Abstract:Abstract: Structures in metamorphic terrains are very complex and very difficult to study because of polyphase superimposition. So to recognize superposed folds correctly is one of the keys to identify the structures and deformation history in metamorphic terrains. This paper proposes a method of processing images by extracting the practice and checks of this method in the Tonghuashan-Liuhuangshan area in the eastern segment of the South Tianshan Mountains, good results have been achieved.

Abstract:Abstract: As an important component part of a regional geological map, the cutting section can reflect the characteristics of subsurface strata and structure. but previously the cutting section of a geological map was produced by hand, so the production efficiency was low and the secfion not easy to kecp and update. The main steps of the production are as follows: (1) preparation of a vectorized geological map, (2) automatic production of a cutting section by the computer, and (3) interactive modifying and output of the cutting section. Take for example the geological map of the Yujiashan area, Wuhan City, this paper proves that this system has high efficiency and good quality and so can meet the requirements for producing the cutting sections of geological maps of various scales.

Abstract:Abstract: The National Longmenshan Geopark, one of the first group of 11 national geoparks, was established by sanction on March 16,2001. As an exceedingly large structure-type national geopark, its tourism resources, scope, planning, development and protection, management system, scientific research and legislation have not been standardized, i. e. the theoretical system of geoparks has not been perfected. How to develop tourism in geoparks is an important issue that needs urgent solution. This paper discusses the establishment and significance of the Longmenshan Geopark and reviews the superiority of its geoscience tourism resources. Several measures for the development and protection of this geopark are put forward according to its present conditions and through a comparison with national parks abroad and scenic spots at home.