Abstract:Abstract：The gas hydrate-related activities may largely go through four development stages: laboratory curiosity, pipe clogging and its prevention and control, resource investigation and exploitation and utilization. At present China is in the early phase of the resource investigation stage. Since 1999, scientists of China have carried out gas hydrate investigations and research in the South China Sea, East China Sea, offshore permafrost zones and international sea-floor areas and found a number of geological, geophysical and geochemical anomalies of gas hydrate and successfully collected samples of gas hydrate in the Shenhu area in the northern South China Sea. Then a major breakthrough was made in mineral exploration and good prospects are shown in the area. However, at present there are still some problems such as a lower exploration level and relatively backward exploration techniques and equipment. With more importance attached to gas hydrate by China, gas hydrate investigation and research in China will be further accelerated and in the near term the stage of resource investigation will pass into the stage of trial production and the stage of commercial production.

Abstract:Abstract：Meso-and Neoproterozoic strata are very well developed in the southern Ural Trough. They have a huge thickness and show distinct features of tectonic evolution and deposition of several stages. The Neoarchean and Lower Riphean are important host strata of large stratabound iron and magnesite deposits. The Middle Riphean (Mesoproterozoic) has very thick deposits with several depositional cycles, when carbonate rocks of abyssal to ramp facies were developed. After the Neoproterozoic last glaciation, the White Sea fauna (Ediacaran fauna), which may be used for global correlation, appeared in the Vendian System. The authors for the first time recognize three sets of molar-tooth structures in the Meso- and Neoproterozoic strata of the Southern Ural area. Of these, the molar-tooth structure in carbonate rocks of the Bakal Formation alternates and is associated with seismic liquefied veins, and even the molar-tooth structures are also developed in large-scale stromatolites in the lower Riphean Staka and Bakal formations. This feature indicates that the molar-tooth structure in carbonate rocks is related to seismic liquefaction. The age of the three sets of molar-tooth structures is largely close to that of the molar-tooth structure (liquefied vein) found in the Meso- and Neoproterozoic strata in the North China block.

Abstract:Abstract：Based on Shastasaurus neoscapularis, which was firstly described from the Late Triassic Norian of British Columbia, Canada by McGowan (1994), Callawayia and Comparison: The new species is similar to Callawayia neoscapularis in a contact between the nasal and postfrontal, well-developed parietal ridge and parietal shelf, contact between the postfrontal and supratemporal, relative slender scapular, and humerus with higher dorsal process, but it can be distinguished from the latter by a narrow frontal, nearly straight frontonasal suture, and a well-developed maxilla dorsal lamina.Metashastasaurus were successively established by Maisch and Matzke (2000) and Nicolls and Manabe (2001). Callawayia is used in this paper according to the ICZN, but its diagnosis is mainly based on that of Metashastasaurus given by Nicolls and Manabe（2001）because the their study was more detailed and correct.The present specimens were collected from micrite of the lower part of the Upper Triassic Xiaowa Formation. It is very important both in biostratigraphy and biogeography because it not only enlarged the geological and paleogeographical range of Callawayia, but also proved the successive evolution of the ichthyosaurs fauna from the Late Triassic Carnian to Norian.The genus Callawayia was usually assigned to Shastasauridae in the past; however, the plesiomorphic features of the skull and appendicular skeleton, which have been recognized from tplete specimens of Shastasaurus from the Upper Triassic Xiaowa Formation by the authors recently, indicate the distinctive difference between Shastasaurus and Callawayia. A formal revision of their systematic position would be worthy of efforts, but it is not the emphasis of this study. Because the humerus, which is broad, short and nearly quadrangular, shares characters of Infraorder Shastasauria Motani 1999, Callawayia is described based on the ichthyosaurs systematic classification proposed by McGowan and Motani（2003）in this paper. Superorder Ichthyopterygia Owen 1840 Infraorder Shastasauria Motani 1999b Family incertae sedis Genus Callawayia Maisch and Matzke 2000 Callawayia wolonggangense sp. nov. Etymology：Wolonggang-, a hill, about 3 km north of Xinpu Town, Guanling, Guizhou Province. It is well-known where abundant and well-preserved marine reptiles and crinoids fossils were found.Holotype：Sample No. SPCV10306 of the Yichang Institute of Geology and Mineral Resources, a nearly complete articulated skeleton Paratype：Sample No. SPCV10305 of the Yichang Institute of Geology and Mineral Resources, a flatten skull.Typical locality and horizon: Xinpu Village, Guanling County, Guizhou Province; Xiaowa Formation, Canian, Upper Triassic.Diagnosis: Medium-sized ichthyosaur with along snout, which was almost covered by premaxilla; maxilla dorsal lamina contacting prefrontal; frontal separating from prefrontal by contact between nasal and postfrontal; narrow frontal entering supratemporal fenestra, and forming a trough anterior terrace of upper supratemporal fenestra; parietal ridge and posterior parietal shelf well-developed; postorbital and squamosal separating from supratemporal fenestra by contact between postfrontal and supratemporal; dorsal central being anterior concave; scapular shaft elongated; humerus being short and broad, with well-developed dorsal process; leading edge of flipper notched, front flipper with 4 digits.

Abstract:Abstract：Neogene Pliocene-Quaternary early Pleistocene strata have been determined through analyses of paleomagnetic and ESR samples from a section of fluvio-lacustrine strata in the Zanda basin, Ngari, Tibet. The analytic results show that： the paleomagnetic ages obtained in ascending order from the section are 5.41-1.60 Ma, while the ESR ages are 5.40-1.36 Ma. The two analytic results roughly coincide. According to the results of the paleomagnetic and ESR datings, the time series of the fluvio-lacustrine strata is as follows： the Pliocene Tolin Formation (N12t) formed at 5.41-4.20 Ma, the Pliocene Guge Formation (N22g) formed at 4.20-2.57 Ma and the Quaternary early Pleistocene Qangzê Formation (Qp1-1x) formed at 2.57-1.36 Ma. This study provides an important basis for the establishment of the time scale of the Neogene Pliocene-Quaternary early Pleistocene strata on the Qinghai-Tibet Plateau and division and correlation of the Neogene Pliocene-Quaternary early Pleistocene fluvio-lacustrine strata.

Abstract:Abstract：The Shihua cave is located at the northeastern end of the synformal belt at the edge of the Fangshan granite intrusion in Beijing and faces the Peking Man (Homo erectus pekinensis) site. The strata are composed of limestone of the Middle Ordovician Majiagou Formation formed 460 Ma ago. The basic form of the cave began to form in the Pliocene at 25 Ma BP and the speleothems in the cave began to form in the middle Pleistocene at 0.37 Ma BP. Among Chinese karst caves, the Shihua cave has the largest number of layers and a complete range of speleothems in the caves. There are many large cave stone shields deposited by fissure infiltration water, the superimposed relationship of stalagmites deposited by dripping water is evident, moonmilk deposited by pool water is well developed, and the micro-layering of Holocene stalagmites is clear. The basic form of the cave reflects the history of the neotectonic movement in the Western Hills, Beijing, which may be correlated with the physiographic stage of North China and terraces of the Yongding River; the speleothems in the cave recorded the paleoenvironmental change in the Western Hills, Beijing, since the middle Pleistocene, which may be used to set up a Quaternary section for a correlation with the section of clastic sediments in the Zhoukoudian caves. The calcareous plate has U-series ages of 334.99-366.74 ka, thus named the Gaiban Formation. The wide stalagmites have U-series ages of 169-235 ka and ESR ages of 130-518 ka, which are middle Pleistocene deposits and may be named the Yunshuidong Formation. The rod-shaped stalagmites have U-series ages of 14.9±2.1-100.3±11.1 ka, which are upper Pleistocene deposits, named the Shihuadong Formation. In Holocene stalagmites, there is usually a ~1 μm thick, dark streak between two micro-layers, which serves as a mark for determining the number of micro-layers. Stalagmites with micro-layering have 14C ages of 0.58-2.50 ka and AMS 14C ages of 130±100-670±130 a, named the Shoubeizhidong Formation.

Abstract:Abstract：Plenty of Indosinian intrusive rocks outcrop in the Bikou massif in the Wuping area, northwestern Sichuan, but accurate chronological data are lacking. The authors analyzed the interior structures of zircons from the Nanyili granodiorite at the southwest margin of the Bikou massif by using the CL technique, and on that basis, they performed the in-situ zircon U-Pb dating using the LA-ICP-MS and obtained reliable age data. The results show that： the zircons from the granodiorite have higher Th/U ratios, and the CL images display oscillatory zoning in the interior of the zircons, suggesting the features of magmatic origin. The crystallization age of the Nanyili granodiorite is 223.1±2.6 Ma (MSWD=1.4), indicating that the granodiorite formed in the early Late Triassic. The Nanyili granodiorite was intruded later than the main collision period of the Mianxian-Lueyang tectonic belt and emplaced in a post-collision setting or at least in a transition stage from syncollision to postcollision.

Abstract:Abstract：TIMS U-Pb dating of zircons from the Qitaidaban granite in the West Kunlun Mountains yielded an age of 202.2±3.4 Ma (MSWD=8.65), and the apatite fission-track dating of samples taken at different altitudes yielded ages of 24.8-14.0 Ma. Fission-track thermal history modeling, combined with the previous data of 40Ar-39Ar dating, shows that the Qitaidaban granite underwent three rapid cooling stages (uplift and erosion) and two slow cooling stage (uplift and erosion) at least, i.e.: rapid cooling at 202.2-195.4 Ma, 26-15 Ma and since 5 Ma, and slow cooling at 195.4-26 Ma and 26-15 Ma. The rapid deroofing of the ～3 m thick topmost part of the crust below the West Kunlun Mountains took place at 26-15 Ma and since 5 Ma, which was the result of Eurasia-India collision.

Abstract:Abstract：A significant change in composition of sediments of the northern South China Sea took place in the terminal Oligocene (23.8 Ma BP), accompanied by an abrupt change in geochemical composition, and meanwhile there occurred a depositional hiatus and olistostromes in abyssal sediments. These sedimentary events coincided in time with the jump of direction of the seafloor spreading axis of the South China from E-W to NE-SW, representing the most important tectonic event in the tectonic evolution of the South China Sea since the Oligocene. Through this tectonic event, the sedimentary environment in the Baiyun subbasin was transformed from the neritic continental shelf in the late Oligocene to the continental slope since the early Miocene and the provenance of sediments in the northern South China changed from mainly proximal areas in the Oligocene to mainly distal areas in the Miocene, and furthermore, the region has generally exhibited the feature of sea transgression since the early Miocene in the area. This abrupt change event has far-reaching influence on the formation of petroleum accumulations in the northern South China Sea.

Abstract:Abstract：Major element characteristics of sandstones from different kinds of basin are a function of particular provenance types and tectonic environments, and provenance analysis of basins may be performed using major element diagrams. Based on previous research, the authors selectively collected 569 major element data of sandstones with different tectonic environments, which are divided into 70 sets of average values. According to related references, the authors identify five kinds of provenances and tectonic environments: craton interior, continental arc, collisional orogenic belts, continental island arc and oceanic island arc. Based on an integrated analysis of the correlation between major elements in the sandstones collected, by using the correlation coefficients of the whole and major elements in sandstones derived from different provenances, the authors obtain five assemblages of major element oxides: SiO2, Al2O3+FeOT, K2O+Na2O, MnO+TiO2 and MgO+CaO, and then a triangular discriminant diagram of (Al2O3+FeOT)/(Na2O+K2O)-SiO2/(MnO+TiO2)/100-MgO+CaO is established. Two discriminant functions, F1 and F2, which are correlated with SiO2, CaO, MgO, FeOT, K2O, MnO, Al2O3, Na2O and TiO2, are gained by a discriminant function analysis of the collected data and a discriminant diagram of tectonic environments for two-variable (F1 and F2) provenances is established. According to the main elements in detrital grains of sandstones, the contents of quartz, feldspar and basic lithic minerals in the sandstones are analyzed using the molar percentages of the major elements to constrain the provenances. The constructed Qel-Fel-Lel diagram not only reflects the discrimination of the provenance and tectonic environments of sandstone by major elements but also approximately shows the composition of fragments in sandstones in related environments.

Abstract:Abstract：The Puguang gas field is the biggest and deepest gas field recently found in the Sichuan basin, southwestern China. Recently a major breakthrough has been made in this gas field. The intensive study of the model of accumulation of materials in the shoal-reef compound gas deposit of the field has certain guiding significance for the prediction of favorable exploration areas of carbonate rocks in northeastern Sichuan and even the whole Sichuan basin. Controlled by the Kaijiang-Liangping inter-platform basin, a carbonate sedimentary system similar to Wilson's facies model is developed in the Changxing Formation and Feixianguan Formation in the Puguang area at the east side of the inter-platform basin, where there mainly occur platform evaporates, restricted platform, open platform, platform-margin reef-shoal, slopes and inter-platform basin sedimentary facies, but continental shelf facies is not well developed. The paleogeographic differentiation mainly evolved centering around the development and filling of the Kaijiang-Liangping inter-platform basin. The study of the sedimentary microfacies and microscopic geological characteristics of the reservoirs indicates that the platform-margin shoal reef facies is the most favorable facies belt for the development of reservoirs in the area and that sponge baffle dolomite, sponge skeletal reef limestone, oolitic dolomites and relic oolitic dolomite are main reservoir rock types. The development of favorable reservoirs are mainly controlled by the distribution of the sedimentary facies belt and later dolomitization, dissolution and tectonic processes

Abstract:Abstract：Late Mesozoic intrusive rocks are widespread in the southern part of the Jiangshan-Longyou area, Zhejiang. They were formerly regarded as rocks of the calc-alkali series. Field geological, petrological and element geochemical studies indicate that quartz monzonite, monzonite, syenite and concomitant granite and granite porphyry belong to the shoshonitic series. This suite of rocks has higher contents of alkalis (Na2O+K2O=7.80％-10.47％) and potassium (K2O/Na2O=0.92-1.91), lower titanium contents (TiO2=0.2％-0.88％) and a higher content and wide range of Al2O3 (11.08％-17.77％) and is enriched in large ion lithophile elements(LILE) and light rare earth element(LREE), with high ratios of Ce/Yb(27.29-85.64), Ta/Yb(0.42-0.73) and Th/Yb(3.44-14.44), showing the geochemical characteristics of shoshonitic series rocks. The area is endowed with rich mineral resources, and most ore deposits are intimately associated with shoshonitic intrusive rocks in terms of both time and space. The shoshonitic intrusive rocks are parent rocks of ores, which are an important petrological indicator for ore finding.

Abstract:Abstract：The Yangshan gold deposit is a very finely disseminated gold deposit, which was explored at the turn of the century and expanded into a superlarge deposit. The deposit was controlled by superposition and modification of many factors such as strata, hypabyssal granite-porphyry, brittle-ductile shear and hydrothermal activities. The gold deposit has the characteristics of both Carlin type and Carlin-like type mineralization. The Carlin-type mineralization occurred during the early, early-middle and late stages of ductile shearing, when there appeared the As-bearing pyrite-arsenopyrite-submicroscopic gold-dolomite-quartz assemblage and pyrite-stibnite-quartz-calcite assemblage, as well as the Au-As-Sb-Hg geochemical assemblage. The Carlin-like type mineralization took place during the middle-late stage of brittle shearing, which is characterized by the pyrite-arsenopyrite-native gold-tellurobismuthite-submicroscopic gold-dolomite-quartz assemblage (with chalcopyrite, chalcopyrite and chalcopyrite) and the Au-As-Cu-Pb-Zn-Te-Bi geochemical assemblage. The δ34S values are -24.6‰ to -29.0‰ for sedimentary diagenetic pyrite in ore-bearing strata of the gold deposit, 5.0 to 7.0‰ for the metal sulfide formed during the early and early-middle stage of brittle-ductile shearing and -2.9 to -2.1‰ for the metal sulfide in altered granite porphyry of the middle-late mineralization stage, suggesting the multi-source features of mixing with biogenic sulfur in strata, crustal sulfur in strongly deformed orogenic belts and a little magmatic sulfur. The hydrogen and oxygen isotopes in fluid inclusions show nearly sympathetic variations with δ34S, and hydrothermal ore fluids are the mixture of underground fluids, strongly modified meteoric water and a little magmatic water.

Abstract:Abstract：Abundant tin resources are contained in the southern Hunan region. Tin and tin-polymetallic deposits (occurrences) are widespread in the region and their types are complex. Their formation is not only directly related to granitic intrusions but also controlled by factors such as regional strata and geological structure. According to the geological setting, distribution characteristics, deposit features and mineralization characteristics, deposit genesis and ore search information and indicators, the ore search model for tin deposits in the southern Hunan region may be summarized as “delineation of ore belts and ore districts, search for mineralized intrusions and determination of ore deposit locations”. This model not only macroscopically presents or solves the problem of the direction for looking for tin deposits but also has been applied in ore prospecting in recent years, and fruitful results have been achieved in ore finding.

Abstract:Abstract：The Qianhe gold deposit, Henan, is of tectonic alteration type. In this deposit, orebodies show gradational contact relationships with wall rocks with a vague boundary, but there is distinct difference in magnetic susceptibility among orebodies, wall rocks and various types of altered rocks. Systematic susceptibility measurements were made of altered rocks in various levels and along exploratory lines of the Qianhe gold deposit using a WCL-1 portable contact magnetic susceptibility meter. The susceptibility values of various kinds of typical altered rocks are in decreasing order as follows: chloritized rocks (Ch) → silicified-chloritized rocks (Si+Ch) → chloritized-silicified rocks (Ch+Si) → K-feldspathized rocks (Kf) → silicified (Si) → pyritized-phyllic rocks (Py+Se+Si). Correlation analysis of the magnetic susceptibilities of altered rocks and degrees of gold mineralization indicates that there is a negative correlation trend between them. Profiles of magnetic susceptibilities of altered andesite along lines 78 and 83 and a vertical longitudinal projection map of magnetic susceptibilities and gold grade isolines in the ore district have been constructed, and the direction for looking for ore deposits at depth in the ore district has been predicted preliminarily.

Abstract:Abstract：An Early Paleozoic to Middle Mesozoic sequence of carbonate rocks with finely clastic rocks occurs in the Paleozoic South Qinling sedimentary basins at the passive continental margin of the northern part of the Yangtze plate. A huge and unique lead-zinc-gold polymetallic metallogenic belt formed there. Normal sediments and hydrothermal sediments coexist in the same rift or downfaulted basins formed in an extensional regime. The hydrothermal sediments superimposed upon the normal sediments, which was a "sudden or catastrophic event", have the special material composition and mode of occurrence. Recognition and hierarchical division of the sedimentary ore-forming basins in this area show that several third-order tectono-hydrothermal sedimentary subbasins usually occur at margins of second-order sedimentary subbasins. They are controlled by contemporaneous faults and characterized by particular sedimentary facies, hydrothermal sedimentary rock associations, significant ore-forming processes and wide distribution of geophysical and geochemical anomalies. The third-order tectono-hydrothermal sedimentary subbasins are tectonic spaces for localization of ore deposits, and the fourth-order hydrothermal sedimentary subbasins are spaces accommodating orebodies (ore beds). The hydrothermal sedimentary rocks in the region are mainly barite (witherite) rock, siliceous rock, albite rock and ferro-carbonate rock. Mineral resources such as lead, zinc and barite mostly occur in the hydrothermal sedimentary rocks or in their hanging walls. The hydrothermal sedimentation generally evolved from early-stage hydrothermal eruption and replacement through main-stage hydrothermal effusion to late-stage hydrothermal exhalation. The early-stage hydrothermal eruption and replacement usually result in stockwork and brecciform mineralization along the conduits of ore fluid eruption. The main-stage hydrothermal effusion mainly gives rise to hydrothermal effusion facies and polymetallic mineralization, characterized by massive, banded and laminar ores or hydrothermal sedimentary rocks. The late-stage hydrothermal exhalation mainly produces disseminated ores and exhalative rocks.

Abstract:Abstract：The authors amended the ore prospect regionalization and evaluation method based on the Expert Weights of Evidence that were proposed previously by the author and re-delineated and re-evaluated Au, Cu and Co ore prospect areas in the East Kunlun region, Qinghai. According to their potentials, the prospect areas of these metals were divided into classes A, B and C, and on that basis, the authors proposed the methods for combining several single-metal prospect areas into composite ore prospect areas and evaluating these composite prospects. A total of 25 composite prospect areas were finally delineated in the East Kunlun metallogenic belt of Qinghai, and they were also classified into classes A, B and C based on their ore potentials. The results are thought to be satisfying according to the numbers, sizes and distributions of the known Au, Cu and Co deposits (occurrences) in various composite ore prospect areas in the East Kunlun region, Qinghai. The delineation and assessments of composite ore prospect areas in the East Kunlun metallogenic belt, Qinghai, may provide a scientific basis for further arrangement of mineral prospecting work.

Abstract:Abstract：The total predicted resources and identified reserves of oil shale in northwestern China are at least 40 billion t, equivalent to ~2 billion t of shale oil. The demonstrated reserves are mostly of small or medium size. Oil shale deposits in northwestern China may be classified into the following three types： Mid-Late Carboniferous littoral-neritic sedimentary deposits, Late Permian lake and lake-bay sedimentary deposits and Mesozoic inland lake sedimentary deposits. The oil shale districts differ in area significantly; and the thickness of a single bed of oil shale generally ranges from 1 to 5 m and the total thickness also changes significantly in different oil shale districts. Oil shale is commonly brownish black and black with a slight greasy luster, and its oil content is 5-10%. Oil shale mostly occurs as beds. The oil shale formed in the Mid-Late Carboniferous and Jurassic commonly occurs in association with coal beds. The younger the oil shale is, the higher its REE abundance will be. All the identified oil shale deposits in northern China are located near large and medium-sized cities and have good prospects for exploitation and utilization. The Bag Maode area, Inner Mongolia, is very promising for oil shale.

Abstract:Abstract：The exploitation and utilization of shallow geothermal energy by using the heat pump technology are developing quickly. In order to ensure the rational and sustainable development of shallow geothermal energy, exploration and evaluation are necessary. Through regional survey of shallow geothermal energy, we can ascertain the quantity, quality and distribution of regional geothermal energy at shallow depths to work out a plan for its exploitation and utilization, thus providing a basis for sustainable use of shallow geothermal energy. Exploration of shallow geothermal energy for the ground source heat pump project can offer a reliable basis for the use of shallow geothermal energy for the underground heat exchange system. The environmental evaluation and economical evaluation are the essential content during the exploration. The methods for calculation and assessments of shallow geothermal energy are for the first time put forward systematically in this paper.

Abstract:Abstract：Based on an intensive analysis of the sedimentary and tectonic evolution in the central part of the Bozhong depression, the paper reveals the characteristics of faults and their distribution in the area. A geological structural model of the central part of the Bozhong depression is constructed using E44-6101 type epoxy resin as matrix, maleic anhydride as a condensate and dibutyl phthalate C.P. as plasticizer, and experimental photoelastic modeling is performed for the tectonic stress field of the study area. Then the stress state and distribution of the nearly NNE-and nearly E-W-trending faults in the Neoid tectonic framework are reproduced. The experimental results show that under the action of the tectonic stress field petroleum usually migrates from the high-stress value zone to low-stress value zone and that the direction of the maximum principal compressional stress has been relatively stable in the Bozhong area since the Neogene. Based on an analysis of the experimental results, the paper discusses the characteristics of the NNE and nearly E-W sets of faults under the Neoid stress field and their controls on petroleum. As the Bozhong depression is China's major petroleum production area, the study of the distribution of the tectonic stress field of the basin can produce a basis for petroleum exploration and development of the basin

Abstract:Abstract：We may deduce the stress field orientation in the fault belt by an integrated analysis of the calcite petrofabric in tectonite of a fault belt and deduce the orientation of the paleostress using the C (compressive)-T (tensile) stress diagram of calcite with e-twins. The methods have been applied by many geologists in the practice. In the Baiyangping east ore district of Yunnan, the Huachangshan and Shuimofang faults are the principal ore-controlling structures. The petrofabric diagrams of calcite optic axis and e-twin poles both show c-axis pole maxima and girdles, indicating that the compressive stress in the c-axis direction causes gliding along the ab plane. In the C-T stress system, the principal compressive stress is oriented in a SE-NW direction and the principal tensile stress is oriented in a NE-SW direction, and the sinistral motion predominates for the Huachangshan and Shuimofang faults; the SE block of the Huachangshan fault is thrust in a NW direction, while the Shuimofang fault is thrust antithetically from NW to SE. These coincide with the macroscopic structural analysis in the field.

Abstract:Abstract：Based on the satellite images, combined with field surveys and thermoluminescence dating of Quaternary sediments, the authors explain and analyze the step-like landform system of the Gonghe basin. Study shows that the landform system consists of the piedmont denudation surface, proluvial fan surface, basin surface and terrace surface. Its spatial structure and material composition clearly record the early Early Pleistocene C phase of the Qinghai-Tibet orogeny and late Middle Pleistocene Gonghe orogeny. Phase C of the Qinghai-Tibet orogeny witnessed the disintegration of the main planation surface during the differential uplift of the plateau, with a vertical displacement of as high as 1700 m. The Gonghe orogeny caused the Yellow River to enter the Gonghe basin at 0.11 Ma. Since then, substantial down-cutting of the basin surface has continued to the present at an average rate of 3.5 mm/a. At the same time, the piedmont paleo-proluvial fan at the margin of the basin has been elevated at about the same rate. Ultimately, a step-like landform system with a height difference of about 2000 m appeared.

Abstract:Abstract：Tufa in Huanglong is the product of several ten thousand years of karst geological processes. In recent years, the tufa has gradually dried up, blackened and been sandified, which has seriously affected the aesthetic characteristics. Water resources have played an important role in the development and change of the Huanglong tufa. The authors have collected and analyzed the monitoring data in the area and found that the monitoring system is not sound and that the data of the time sequence are lacking. According to these features, the authors choose a grey system model which does not require too much of the data of the time sequence and may yield a good result of prediction. They predicted the tufa development using pH as a proxy and used the kriging method to make interpolation of the results of prediction and thus obtained the prediction results of the tufa in the whole Huanglong area. Based on the pH values, the tufa development is divided into three types: strong erosion, weak erosion and accumulation. The Huanglong tufa is now in the stage of dynamic balance and decline and recombination.