Abstract:Abstract：Orogenic granitoids in the continent of China may fall into the east and west regions. The orogenic granitoids in the west region include the Central Asian orogenic belt, Qinling-Qilian-Kunlun orogenic belt and Gangdise orogenic belt in the Qinghai-Tibet Plateau, which are associated with the development of the ocean, and the orogenic granitoids in the east region, including Northeast China, North China and South China, are Yanshanian orogenic granitoids formed after the assembly of the continent of China. Based on the settings and geological and geochemical characteristics of granitoids of different orogenic belts (exemplified by orogenic granitoids in Altay, East Kunlun, Yanshan in North China, Northeast China and Nanling in South China), the relationships between granitoids and continental crustal growth are discussed, and five modes of continental crustal growth in the continent of China are proposed；they are as follows:(1)the Altay mode of continental growth is that the material and heat of the Paleozoic convertive mantle formed on the background of the Paleo-Asian Ocean were input into the Paleozoic continent and mixed with the materials of the upper crust；(2) the East Kunlun mode is that the basement of the Proterozoic orogenic belt was reworked by the heat input and materials of the Paleozoic-early Mesozoic convective mantle formed on the background of TTG continental crust of the Proterozoic orogenic belt；(3) the Northeast China style is that the Phanerozoic continental crust was reworked by the heat input and materials from the convective mantle formed on the background of the Yanshanian Central Asian orogenic belt；(4) the Yanshan mode is that the Archean basement was reworked by the heat input and materials from the Yanshanian convective mantle；and (5) the Nanling mode is that in South China what was input by the Yanshanian convective mantle into the continent was mainly heat and subordinately materials and the crustal material recycle was the dominant mode for the continental growth (showing zero continental growth). These modes are the basic modes for the Phanerozoic continental growth of the continent of China.

Abstract:Abstract：Regional mapping and isotope dating indicate that the upper and lower subgroups of the Huade Group are located in stratigraphically equivalent horizons rather than have an overlying and underlying contact relationships, and that the Bayan Obo Group in the Shangdu area is also a part of the Huade Group. According to a detailed structural analysis and stratigraphic sections，the stratal sequences of the Huade Group have been reconstructed；the group may be subdivided in ascending order into the Maohuqing Formation，Gejiaying Formation and Sanxiatian Formation. Zircons from the complex intruded into the Huade Group yielded U-Pb ages of 1 808 Ｍａ, 1 853 Ｍａ， 2 091 Ｍａ and 2154Ma suggesting that Huade Group formed in the Paleoproterozoic rather than Meso- and Neoproterozoic as thought previously. The Huade Group underwent at least two phases of deformation：the early phase of deformation gave rise to ENE-trending synclinorium and the late phase was marked by tectonic superimposition，forming NNW-trending folds. The main phase of deformation likely occurred in ~2.0 Ga B．P.The deformation of the Huade Group is related to a Paleoproterozoic orogenic event along the northern margin of the North China Craton, which has great significance for the study of accretion and breakup of the North China Craton.

Abstract:Abstract：A low-grade metamorphic series composed of marine sandy, muddy and siliceous sediment is widespread in Changting and Shanghang, southwestern Fujian. According to the regional geological survey of the 1：250000 Ruijin Sheet, the “Dingwuling conglomerate” is determined to be of Late Devonian age and thus separated from the low-grade metamorphic series. In this paper, the low-grade metamorphic series that conformably underlies the Lower-Mid Cambrian Lintian Formation is divided into the Jiangshekeng Formation，Laikeng Formation，Nanyan Formation and Huanglian Formation.

Abstract:Abstract：The subsidence history of the Zengmu basin since the early Miocene is studied by the backstripping technique with Airy isostatic correction and the characteristics of the tectonic evolution of the basin are discussed in the paper. The Zengmu basin underwent four periods of rapid subsidence since the early Miocene; they are 17.5-11.6 Ma, 11.6-5.5 Ma, 5.5-3.0 Ma and 3.0-0 Ma. The tectonic evolution of the basin was controlled by combined actions of the collision of the Zengmu block with the Nansha block and Borneo block and the Wa′an-Lupar fault and Tindja strike-slip fault on its both sides. Three evolutionary stages may be distinguished, i.e.：bi-directional N-S compression (late Eocene-early Miocene), strike-slip modification (middle Miocene-late Miocene) and regional subsidence (Pliocene-Quaternary).

Abstract:Abstract：During the evolution of the Tarim superposed basin, the Tabei uplift went through three stages： old craton uplift, early foreland front uplift and Kuqa regenerated foreland basin slope. It experienced two stages of basin-forming structural transformation, giving rise to the deep- and shallow-level systems of overlapped faults in the north of the Taibei uplift： the deep-level fault system is a basement thrust one marked by a combination of thrusts and backthrusts, and the shallow-level fault system is a normal fault one, marked by a combination of grabens and horsts. The two fault systems with different characters correspond to two stages of formation of the foreland basin in the orogenic compressional environment. The deep faults were not formed in the early foreland deformation zone but resulted from fracturing of rocks during the longitudinal buckling of the intraplate Tabei old craton uplift in a compressional environment. The shallow faults are the result of extensional fracturing of the overlying strata due to lateral compressional warping deformation (longitudinal buckle deformation) of the basement (pre-Mesozoic tectonic layer) in the north of the Tabei uplift in the stage of the Kuqa regenerated foreland basin.

Abstract:Abstract：Triassic granites of magma mixing origin are widespread in the East Kunlun orogenic belt. They have the following common features： the composition of granites varies greatly; granites contain abundant mafic microgranular enclaves (MME); and different rock types tend to show gradational relationships. Particularly, these rocks co-exist with low-grade metamorphic rocks representing the lower crust without exception, implying that the magma was emplaced in the deep crust. In addition, basic intrusive rocks are widely developed in the area. They either occur in high-grade metamorphic rocks or occur together with granites of magma mixing origin, suggesting that partial melting of the lower crust and formation of the granites of magma mixing origin are probably related to underplating of basic magma. Take for example the Jialuhe granite—a typical granite intrusion of magma mixing origin in the East Kunlun area, the authors studied in detail its petrological, geochemical and isotope geochemical characteristics. It is concluded that the mantle-derived magma underplating was the direct cause of the formation of such granites and played an important role in the Triassic crustal growth and tectonic evolution in the East Kunlun orogenic belt. Furthermore, the genetic relation between the mantle-derived magma underplating and granites of magma mixing origin is discussed and a model of breaking-off-underplating-mixing-delamination in the setting of the thickened continental crust is constructed.

Abstract:Abstract：The Cuowomo-Chengxiangcuo volcano-sedimentary basin is located on the south-central edge of the Gangdise block, Tibet. Volcano-sedimentary rocks in this basin are called the Linzizong Group, which is Paleocene-Eocene in age. Geochemical analysis indicates that the Linzizong volcanic rocks belong to a calc-alkaline series, exhibiting enrichment in LREE, different degrees of negative Eu, Ce and Nb anomalies and enrichment in the trace elements K, Rb, Th and Ce and depletion in the trace elements Sr and Ba，especially in Nb, P and Ti. Therefore, the authors tentatively suggest that the Linzizong volcanic rocks formed in a tectonic environment of subduction and arc making and resulted from mixing of basic differentiated magma and crustal anatectic acid magma in different proportions and in different time intervals. In addition, mixing between abyssal sediments on the subducted plate and basic magma is also a factor that can not be negligible. On the basis of an integrated analysis, the authors suggest that the collision between the India plate and Eurasian plate was initiated after 45 Ma.

Abstract:Abstract：Early Cretaceous volcanic complexes in the Genhe area in the northern segment of the Da Hinggan Mountains may be divided into three types according to their petrological and geochemical characteristics. Type I is composed of rhyolitic rocks, which are characterized by higher Si and alkali contents and lower Al and Ti contents, Na2O/K2O＜1, a pronounced negative Eu anomaly (δEu=0.27–0.59), enrichment in Rb and depletion in Sr and Ba. Type II consists of trachydacitic rocks, which are enriched Al and Ti, with Na2O/K2O＞1 and a weak negative Eu anomaly (δEu=0.65–0.95), enriched in Sr and Ba and poor in Rb. Types I and II probably formed in an extensional to postorogenic extensional environment, accompanied by compressional uplift. Type III is composed of latite and benmoreite, which are enriched in Al and Ti, with Na2O/K2O≥1.1 and no negative Eu anomaly (δEu=0.93–1.06), and Th/Ta and Ta/Hf ratios indicate a continental intraplate extensional environment. Its formation is probably related to underplating of basaltic magma.

Abstract:Abstract：Detiled field geological mapping and geochemical study show that the Fuling rock mass in southern Anhui is enriched in Si ,Al，ａlk , high-field strength elements ,REE ,Rb and depleted in Sr and Ba,belonging to aluminous A-type granites. These characteristics suggest that the magma originated by partial melting of the lower crust. The rock mass rose and was emplaced rapidiy along fault in a post-orogenic extensional environment,and the magmatic differentiation was incomplete.

Abstract:Abstract：Cretaceous volcanic rocks in Zhejiang Province occur on two different basement tectonic units:the Yangtze block and Cathaysian block. There is great difference in Nd isotopic composition between volcanic rocks of the two different tectonic units. The εNd values of volcanic rocks of the Yangtze block are higher, ranging between –8.9 and –0.9 with a mean of –4.6 (n=33), whereas the εNd values of volcanic rocks of the Cathaysian block range from –1.41 to +1.2 with a mean of –6.7 (n=69). Furthermore, the εNd values of volcanic rocks of the two blocks increase with time and the model ages show a very marked trend of decrease with time. In the Yangtze block the mean εNd and t2DM values of acid volcanic rocks from cycle I formed at 135-124 Ma B．P． to cycle III formed at 110-900 Ma B．P． are -6.2,-2.4 and -2.2 and 1.42, 1.11 and 1.09 Ga respectively. In the Cathaysian block the mean εNd and t2DM values of acid volcanic rocks of the contemporaneous three cycles are -10.1, -7.2 and -5.5 and 1.75, 1.49 and 1.35 Ga respectively. It is inferred that the Cretaceous rhyolitic rocks developed widely in Zhejiang Province probably originated by partial melting of the basement metamorphic rocks. Continuous underplating of basalt resulted in significant increase of introduced mantle-derived materials with time.

Abstract:Abstract：Hydrothermal sedimentary albitite in the Upper Paleozoic in the South Qinling is closely related to many large-superlarge lead-zinc deposits in the south Qinling orogenic belt． Recently, a nearly E-W-striking, over 10 km long albitite zone has been recognized for the first time in the Lower Silurian Meiziya Formation in a Lower Paleozoic lead-zinc ore deposit concentration area of the Xunyang basin, South Qinling. It shows a conformable contact and gradational relationships with the country rocks and has thick-bedded and massive, banded, brecciated structures and fine and very fine equigranular and intraclastic textures． It is chemically characterized by enrichment in SiO2, Al2O3 and Na2O and is rich in the trace elements Fe and Mn and poor in the trace elements Co, Ni and Cu. Its ∑REE, LREE and HREE are lower than those of the country rocks and exhibit pronounced Eu depletion. The chondrite-normalized REE distribution patterns are inclined to the right. In comparison with the petrography and petrochemistry of hydrothermal sedimentary albitite in the Devonian of the Qinling, combined with the fact that its Lower Paleozoic belongs to a passive continental-margin rift environment on the northern margin of the Yangtze plate，the authors think that the Lower Paleozoic albitite in question is probably of hydrothermal sedimentary origin.

Abstract:Abstract： Hierarchical units of the Dayishan granite are determined through geological and geochemical survey and study of the rock body. The authors think that the Dayishan granite is a composite intrusion formed by three phases and multiple stages of Indosinian and Yanshanian magmatic activities. Mineralization is mainly related to Mid-Late Jurassic granitic magmatism. The authors give the following points of understanding of tin-polymetallic ore-bearing granite： (1) Granitic magma in the same super-unit evolved from acid to acid-alkaline (calcium-poor and alkali-rich) composition from early to late times, i.e. the later-stage acid-alkaline intrusions show more marked metallogenic specialization. (2) Plagioclase commonly has An=4 to 15, with albite predominating； biotite has Mf<1.20, belonging to siderophyllite-ferruginous biotite； the granite has high silica with SiO2＞73%, higher alkalis with Na2O＋K2O＞7.5% and K2O / Na2O＞1.20 and lower calcium with CaO＜0.80%, and the peralumina index AKNC>1.10, alkalinity AR>2.5 and differentiation index DI>50； the ratio of the number of oxygen atoms to the total number of molecules is >1.98 and is rich in F and B； LREE is enriched relative to HREE and the value of Eu depletion is <0.30. (3) The rock shows higher Sn, W, F, As, Sb, Pb, Zn, Cu and U anomalies and the placer minerals are cassiterite, wolframite, antimony minerals and cinnabar, as well as lead, zinc and copper minerals. (4) The Indosinian-Yanshanian NW-trending Chenzhou-Shaoyang fault is of sinistral compresso-shear origin in the early stage and shows tenso-shear, compounding and multiple transition features； the syntectonic granitic magma was emplaced sequentially in three phases obliquely along the NW-trending tectonic belt from southeast to northwest. Tin-polymetallic deposits (occurrences) are distributed around the intrusion. The deposit types mainly include the altered granite type, greisen dike type and fractured type. The metallogenic conditions and ore indications are also summarized and analyzed.

Abstract:Abstract：Otavite was discovered as early as 1951, but the present discovery of this mineral in the Nuwjiaotang cadmium-zinc deposit, Guizhou, is probably the first report of its discovery in China. Otavite grains are very tiny in size, being commonly only several microns, and the large ones are several tens of microns. It often occurs as loose aggregates, crustified veins or films in association with smithsonite and greenockite in the Nuwjiaotang cadmium-zinc deposit. This discovery fills up the blank of mineralogy in China. Otavite has great significance in the environmental protection.

Abstract:Abstract： Mofanggou style gold deposits refer to gold telluride deposits occurring in calcareous dolomite and dolomitic limestone in the Early Cambrian Zhushadong Formation in the Tongshi area，western Shandong. According to recent geological exploration, the horizon of the orebodies is relatively persistent and widespread, with relatively continuous mineralization. Deposits of this style have great resource potential and ore prospects. The notable wall-rock alteration types include pyritization-sericitization-silification, kaolinization, calcitization and fluoritization. The formation of gold telluride deposits is closely related to pyritization-sericitization-silification. The favorable structural sites for forming this style of deposit are the core region of the western Shandong mantle branch and secondary detachment zones above the main detachment zone between the Archean crystalline basement and Cambrian covers surrounding the Tongshi uplift. Ore-forming materials were derived from a deep source (the mantle) and the emplacement of orebodies is controlled by the main and secondary detachment zones. As the secondary detachment zones are distributed parallelly to bedding, the orebodies show the stratiform feature.

Abstract:Abstract：Study of metallogenic conditions of Devonian-Silurian lead-zinc deposits in the Zhenxun (Zhen′an-Xunyang) ore filed shows that Devonian-Silurian lead-zinc deposits in the area generally belong to stratabound deposits. The lead-zinc deposits occur in the Lower Silurian Meiziya Formation, Middle Silurian Shuanghezhen Formation, Middle Devonian Dafenggou Formation and Upper Devonian Nanyangshan Formation. The ore-controlling structures are faults and folds and ore-hosting structures are bedding-parallel fault zones and shear zones; ore-bearing rocks are carbonaceous sandstone, phyllite, limestone, biogenic limestone and dolostone; the sedimentary environments are the shallow-water shelf, tableland margin, lagoon, tidal flat and tableland shallow sea. The Silurian lead-zinc deposits represented by the Sirengou deposit of Xunyang are of fine clastic sedimentary-strongly reworked type; the Devonian lead-zinc deposits represented by the Dalin and Zhaojiagou deposits of Xunyang are of carbonate sedimentary-weakly reworked type and the Devonian lead-zinc deposits represented by the Xitonggou and Yuexi deposits of Zhenan are of carbonate sedimentary-strong reworked type.

Abstract:Abstract：The Pengshan Sn-polymetallic ore filed is a large Sn-, Pb- and Zn-rich orefield found recently in the Jiujiang-Ruijin area in the middle-lower Yangtze valley. All types of ore deposits are distributed in a halo pattern surrounding the Pengshan buried pluton composed of two-biotite-alkali feldspar granite and biotite monzogranite. The formation of those deposits may be divided into two metallogenic epochs and seven mineralization stages. Analyses of the lead and sulfur isotopic compositions, REE data and fluid inclusions of the Pengshan pluton, typical deposits and country rocks indicate that there is a close relation between the intrusion of late Yanshanian calc-alkaline granite and the formation of polymetallic deposits. The magmatism provided a great deal of ore-forming materials for the Pengshan area.

Abstract:Abstract：The Cenozoic on the northern continental slope of the South China Sea contains abundant petroleum and other mineral resources, so an analysis of its depositional systems can help geologists to guide resource exploration and exploitation. On the basis of the interpretation and study of seismic sections in the Xisha trough and Dongsha sea area on the northern slope of the South China Sea and in light of the seismic facies classification principle of external geometric shape plus internal reflector configuration, eight typical seismic facies are recognized in sedimentary beds since the Miocene; they are: sheet-parallel, sheet-wavy, sheet-blank, sheet-chaotic, sheet-foreset, brush-shaped foreset, lenticular foreset and mound-chaotic facies. On that basis, six depositional systems are recognized on the northern slope of the South China Sea; they are: delta, contourite, submarine fan or slope fan, slump block, turbidite fan and fan-delta. Of these, the distribution of the contourite, slump block and fronts of deltas or fans is highly consistent with the distribution of BSR, and thus they are the most favorable facies for gas hydrate accumulation.

Abstract:Abstract：Taking the northern Da Hinggan Mountains for example, the relation between the chemical compositions of soils and bedrocks in shallow overburden areas is studied. The study indicates that the major rock-forming elements in residual soils in shallow overburden areas have the inherited characteristics of the element assemblage of the bedrocks, and that the redistribution and migration of elements in the processes of rock weathering and soil formation result in the homogenization of the contents of most elements (oxides) in soils. Based on the study, the problems about the recognition and appraisal of geochemical anomalies of residual soils are discussed and proposals are advanced in this paper.

Abstract:Abstract：This study demonstrates that the portable infrared mineral analyzer (PIMA) is capable of deriving detailed mineralogical information on hydrothermal alteration at low cost and therefore is an operational tool for mineral exploration. With this technology, hydrothermal minerals can be quickly identified and hydrothermal alteration zones effectively mapped to assist in mineral exploration. Because of the fast data acquisition and no requirement for sample preparation, it becomes practical to measure a sufficiently large number of samples in order to objectively capture the mineralogical variation of a hydrothermal alteration/mineralization system. The results of PIMA application at the Tuwu porphyry prospect show the effectivity of mineral identification and characterizing the porphyry copper mineralization system.

Abstract:Abstract：Sample analyses show that the Neogene red clay at the Laogaochuan section exhibits a trimodal grain-size distribution, suggesting that the red clay is composed of components of multiple origins and that components of different origins make different contributions to the total. The silt-sized grains (5-50μm) are predominant, of which the content of grains of 10-50μm in size is higher than that of grains of 5-10μm and grains >250μm in size are rare. The mean, >63μm and >30μm grain-size curves are highly variable, while the <2μm grain-size curve is relatively stable. The features indicate that the Neogene climate was mainly dry and cold and the winter monsoons had once changed greatly in strength and prevailed over the study area and that the summer monsoons were relatively weaker with little change. The changes of the grain-size curves are supported by the lithologic and biologic evidence, suggesting that the climate then was mainly dry-cold and sometimes alternately warm-wet and cool-dry. The lithology in the field is manifested by alternation of clay beds with calcic concretionary beds and the grain-size curves are manifested by fluctuations of peaks and valleys. The susceptibility curve shows that the climate of the Yushean Stage was warmer and wetter than that of the Baodean Stage.

Abstract:Abstract：Grain-size analysis was performed on sand and dust fall-outs of an exceedingly large dust storm that occurred in Harbin, Heilongjiang Province, on March 20, 2002. The results indicate that sand and dust fall-outs are silty sandy loam. The silt-sized (4–63 μm) fraction predominates, making up 71.18%; the sand-sized fraction (>63μm) accounts for 21.7% and the clay-sized (<4μm) fraction is scarce, accounting for only 7.13%. The grains are of trimodal distribution: the coarse silt-sized (29.2–34.7 μm) fraction forms the first main peak, making up ~7.4%; the medium sand-sized (420.5–500 μm) fraction forms the second main peak, accounting for ~1.29%; and the clay-sized (0.69–0.82 μm) forms the third main peak, accounting for ~0.52%. The mean grain diameter Mz is 28.4 μm, with a sorting coefficient of 1.81, a skewness of 0.044, a kurtosis of 1.494 and a silt/clay ratio of 7.3. The grain-size distribution shows that sand-dust fall-outs in Harbin are the coarsest ones reported ever since in China. The fall-outs were a mixture of sands and dusts derived from different sources and transported over long and short distances, and coarse particles were near-sources materials that were transported by low-altitude airflow. Harbin and its peripheral areas should be the dust fall-out center of this exceeding large dust storm and belong to the center or near-central zone with relatively strong atmospheric dynamic conditions. Nude loose soils, river beds and floodplain fine alluvium, sand-dust of city construction sites and so on in the urban expansion areas of Harbin may all be main material sources of sand and dust fall-outs of Harbin. The focus of the work for preventing sand-dust storms in Harbin should be on controlling sand-dust source areas at the peripheries of Harbin.

Abstract:Abstract：The characteristics of regional organic pollutants are analyzed on the basis of three field analyses of water samples, and numerical modeling of transport of TCE and PCE in groundwater of the study area using GMS and the parameters obtained from indoor experiments and domestic and foreign references. The results of modeling indicate that biodegradation exists in groundwater of the area, but the rate of reaction is very low. This suggests that the concentrations of TCE and PCE are probably maintained at a fairly high level for a very long period of time.

Abstract:Abstract：Xiuyan County is a typical area hit by geological hazards of mountains in eastern Liaoning. These hazards mainly include collapses, landslides and mud-debris flow. On the basis of a wealth of data gathered in field investigations of geological hazards, an access database was established. By using the function of projection change on the platform of the GIS software, the files of the database were transformed into graphic files with an attribute and the distribution map of geological hazards was also constructed. Through the superposed calculation on the vectored layers and the files of hazard points after the research area was gridded, the regionalization map and isoline map of hazard-prone degrees were prepared. The hazard regionalization reveals the spatial distribution of geological hazards and their relations with the geological environment and human activities.

Abstract:Abstract：There are plentiful mineral resources in Qinghai Ｐrovince, China. The sustainable development strategy and planning of the mineral resources should be worked out on the basis of the geo-environment vulnerability assessment. This paper analyzes the geo-environment issues and geo-hazards in Qinghai. The assessment framework of the geo-environment vulnerability in Qinghai was established. The basic assessment principles, criteria and geological indicators for the geo-environment ｖｕｌｎｅｒａｂｉｌｉｔｙ were proposed under this framework. The geo-environment vulnerability evaluation in Qinghai was carried out by using the new SMCE function modules of ILWIS, which is a GIS software developed by ITC. The results indicate that the prospect areas of mineral resources are located in areas of low geo-environment vulnerability. This means that geo-environmental conditions have major constraining effects on the future mineral development in Qinghai.

Abstract:Abstract：In ancient times, due to the lower productive force of the society, the natural environment greatly influenced the evolution of ancient human being, production and residency. According to sporopollen analysis and study and reconstruction of ancient vegetations, combined with studies of the geochemical behaviors of paleosol of the Guanghan layer of the Shanxingdui site and hydrodynamic conditions of ancient rivers, the ancient environment of the Jinsha cultural site was studied in an attempt to provide the environmental background for the study of the Sichuan ancient culture. Study shows that the climate in the cultural period was generally tropical and subtropical warm-humid. Meanwhile, the warm-humid climate alternated with the warm-dry one.