Abstract:In recent years, the geophysical 3D imaging of the mantle has provided a great deal of data and information of deep structures and of the underground material motion, promoting the cognition of the characteristics and dynamics of the shallow mantle system. According to the direction of motion, the material movement in the shallow mantle system can be divided into three main forms: horizontal motion, upwelling and sinking motions. The energy that causes the downward movement of matter in the shallow mantle system is caused by the potential energy generated by the earth's gravity, and the motion in other directions is mainly caused by deep heat and kinetic energy. In addition to the power sources, the direction of the material motion of the shallow mantle system also depends on the material properties of the lithosphere and the asthenosphere, as the high viscosity rocks resist the movement of the material and the low viscosity medium accelerates the movement of the material. The horizontal creep difference of asthenosphere mass produces complex structures such as stretching, underplating and nappe in the lithosphere, and the creeping of asthenosphere material with greater velocity and kinetic energy will certainly drive the movement and deformation of the lithosphere plates. The uprising of the asthenosphere can be further subdivided into three ways, the upsurge motion, the upper welling movement and the diapir motion, which have different effects on the upper lithosphere. The material sinking movement of the shallow mantle system takes many forms, including subduction, delamination and metasomatosis, and is often accompanied with the upwelling of the asthenosphere. These mass movements causes the delamination of the craton crust and the land roots of the lithosphere. Largescale material movements in the asthenosphere, including upwelling of matter in the midocean ridge, collisions of continents, and preland pullups of ocean subduction, are clearly reflected in the global seismic tomography maps. The southeast coast of China is a special area of the material movement of the shallow mantle system, which may be caused by the subduction of the Izonaqi plate in the Cretaceous period, which stimulates the asthenosphere upsurge motion along coast zone of the East Asian continent, and then causes a series of dynamic effects such as magma intrusion and delamination of the lithosphere.

Abstract:The boundary between the Mesoproterozoic and Neoproterozoic in the Yangtze Block in southern China is correlated with a series of orogenies. The stratigraphic correspondence between the Jinning Orogeny, the Wuling Orogeny and the Xuefeng Orogeny is controversialdue to the defitient age data in high resolution that causes the chaotic stratigraphic deivisions. We combined previous studies of the Mesoproterozoic—Neoproterozoic boundary and discussed the petrography,geochemistry and isotopic chronology. With new evidence of the plate tectonics and characteristics of lithology, we discussed the stratigraphy of the Jinning, Wuling and Xuefeng Orogenies. We found evidence that the Jinning,Wuling and Xuefeng Orogenies are overlapped in some areas of Yangtze Block. The end of Jinning Orogeny is around 1000 Ma correlated to strong metamorphism of the strata in Kunyang Group and create the igneous basement of the Yangtze Block. The specified boundaries of the orogenic events are critical to further stratigraphy divisions and correlations of the Yangtze Block for the Mesoproterozoic and Neoproterozoic.

Abstract:The study of Quaternary glaciation is to deduce their landform genesis, ages and environmental indication by meticulous logical reasoning mainly based on observed geomorphologic and sedimentological features as well as obtained chronological results. Identification of the “glacial relics” in Mengshan Mountain was established by inappropriate and even incorrect evidences, resulting in the invalid snow line reconstruction and ice age division. The so- called quaternary glacier relics can be adequately explained by non- glacial genesis. Based on the field investigation of the depositional and erosional landforms in Mengshan Mountain, the authors found that: （1）The Lanmaqiang levee, with typical standing stones and stacked boulders, is discontinuously and asymmetrically distributed on the cutbank at downstream Lanxi Valley; its depositional features including gravel fabric, imbricate structure, muddy bottom and irregular scratches of boulder can be definitely attribute to a debris- flow genesis. （2）The Lanxi Valley is a typical V- shaped valley without clear facet and chatter mark on the valley wall; the non- glaciogenic scratches were sculptured by the rolling boulder entrained in the debris flow. （3）The “chatter marks” reported in Mengshan Mountain is inconformity with the definition and formation mechanisms of chatter mark, which means it is an invalid evidence to glacier relics. This study suggested that using the term chatter mark to describe all the glacial erosional landforms with microscale crescentic features. There are lots of logical fallacies in the paper “Types, characteristics and dating data of glacial relics in Mount Mengshan Geopark, Shandong Province”(Wang Zhaobo et al., 2019&). Taking the paper as an example, this study listed 6 of logical fallacies involved in the paper and pointed out their irrational causes.

Abstract:Objectives: At the turn of the Cretaceous and the Paleogene, major events represented by the extinction of dinosaur clusters and the rise of mammal happened across the globally, and the Cretaceous—Paleogene boundary is research hotspot. Even though important progress has been made in KPB research in recent years, but many important problems in the nonmarine strata has not been solved, so it is necessary to establish a nonmarine Cretaceous—Paleogene boundary (KPB) stratotype. Methods: On the basis of the field work and the research of predecessors, biostratigraphic and magnetic stratigraphic studies were carried out on the Drill PYZK01 in the Pingyi Basin, Shandong Province, a scientific drill. Results: We obtained a rich fossil of paleontology, and according to its distribution characteristics, established one charophyte assemblage: Porochara anluensis—Chara yuntaishanensis var. acuta—Turbochara specialis, one sporopollen assemblage: Deltoidospora adriensis—Rugubivesiculites—Schizaeoisporites. Through the research on the magnetostratigraphy, 8 positive polarity zones and 7 reversed polarity zones are established, and the magnetic polarity sequences of the borehole is built. Conclusions: From the biostratigraphic study of the Drill PYZK01, we consider that the stratigraphic age from 0 to 12.25 m is Paleogene, the stratigraphic age from 37.8 m to 60 m is the latest stage of Late Cretaceous; and the stratigraphic age from 12.25 m to 37.8 m is the transition from Late Cretaceous to Paleogene, the Cretaceous—Paleogene boundary should exist in this part. Based on the magnetostratigraphic study, we proposed a comparison plan with the latest Geomagnetic Polarity Time Scale. At the same time, it is preliminarily suggested that the Cretaceous—Paleogene boundary should be located at 31.98 m of the first member of the Bianqiao Formation in the core.

Abstract:Objectives: A major breakthrough has been made in the gas exploration on sucrosic dolomite reservoir of the middle Permian Chihsia(Qixia) Formation in the northwest Sichuan Basin. However, recent cores show that the development horizon and scale of the sucrosic dolomite is of great variability. Therefore, the key to the distribution prediction of this type of dolomite reservoir is to figure the genetic mechanism out. To solve the problem, study has been carried out on the Chihsia Formation in Shangsi section, such as petrological characteristics, carbon—oxygen isotopes and EPMA(electron probe micro analyzer) of the dolomite, to establish dolomitization model of Chihsia Formation. Methods:The dolomite development in field and petrological characteristics were studied through the outcrop observation, microscope analysis and Cathodo Luminescence observation. The paper combines the in- situ micro- electron probe analysis, isotope geochemistry characterization, petrological characteristics and geological background to trace dolomitization fluids. Results:Four characteristics of the sucrosic dolomite were summarized, including: massive dolomite, developing well in the middle of Chihsia Formation member 2, and leopard dolomite from dolomitic limestone, developing in the lower part of member 1, lower and upper part of member 2. ① Massive dolomite is characterized by medium—coarse crystalline and red luminous under CL(Cathode Luminescence), with Mg/Ca values 0.68, δ 13 C PDB and δ 18 O PDB average values 2.42‰ and -6.18‰ respectively; ② Leopard dolomite developing in the lower part of Chihsia Formation member 1 is characterized by powder—fine- crystalline, micro- sucrose texture and non- luminous under CL, with MgO/CaO values 0.54, δ 13 C PDB and δ 18 O PDB average values 2.42‰ and -6.18‰ respectively; ③ The upper part dolomite with medium—fine- crystalline structure shows a non- luminous core inside and a red luminous rim outside under CL, while the lower part dolomite with medium—coarse- crystalline structure shows dark red luminous under CL. Their MgO/CaO, δ 13 C PDB and δ 18 O PDB average values are 0.59 and 0.68, 2.16‰ and -6.50‰, 3.32‰ and -3.75‰ respectively. Conclusion:Based on the results from filed work and indoor materials arrangement, The results suggest that ① in the lower part of Chihsia Formation, there are two penecontemporaneous exposure surfaces, below which leopard porphyritic karst system developed. ② Eogenetic exposure surface has been identified on the top of Chihsia Formation with clear vertical zonation of karst developed below. Most of the karst dominant channels was dolomitized. ③ Both types of dolomites were formed by superposition of seepage—reflux dolomitization and hydrothermal dolomitization. Due to the vertical zonation and influence degree of karstification, there are differences between the result of two phases dolomitization.

Abstract:Objectives: Climate is one of the dominant factors which control evaporite deposits in Qaidam Basin, but its mechanism remains to be clarified. The aim of this paper is to make a comparison between the evaporite deposit period and glacial period since marine oxygen isotope stage 6 (MIS6), and clarify the role of late Quaternary glacial climate in evaporite deposit. Methods:The authors took 3 salt- bearing profiles (D18, MXK2 and D12) from the western Qaidam Basin as the study object, applied multiple collector inductively coupled plasma mass spectrometry (MC- ICP- MS) to obtain the salt deposit age, and applied X- ray diffraction (XRD) to identify the salt minerals from the profiles. Results: MC- ICP- MS U- series dating indicated the deposit ages of D18 profile are 13.1±2.0 ka BP~15.9±2.5 ka BP, of which the mirabilite deposit belong to the late stage of last glacial MIS2; mirabilite deposit ages in MXK2 profile are 131.7±39.5 ka BP and 158.3±10.8 ka BP respectively, mirabilite deposit ages in D12 profile are 166.6±20.2 ka BP and 198.0±20.6 ka BP, which can correspond to the penultimate glacial period MIS6. XRD analysis confirmed that salt minerals in the 3 profiles were mainly mirabilite, halite and gypsum. Conclusions: Combining the study of this paper and evaporite deposits data of other salt lakes in the Qaidam Basin, this paper proposes that the penultimate glacial period MIS6 and the last glaciation MIS2 are two important salt- forming periods of the late Quaternary in the Qaidam Basin, and the cold and dry climate of the glacial period is favorable for salt deposits such as halite and mirabilite. The fundamental reason for salt deposit in the glacial environment in the Qaidam Basin is the expansion of glacier scale in the surrounding mountains, and the dry and cold glacial climate, resulting in the reduction of the recharge volume of the salt lakes in the Qaidam Basin. Besides, the temperature decrease during MIS6 and MIS2 is the direct genesis of the deposit of cold- phase salt minerals such as mirabilite and epsomite.

Abstract:Objectives: The ophiolite in Guanzizhen is located in the northern margin of the western Qinling Orogen, which is taken as the western extension part of the Shang- Dan (Shangnan—Danfeng) suture zone representing the joint position between North China and Yangtze Blocks. In this paper, we focus on the geochemical features of the ophiolite in Guanzizhen to analysis its source area characteristics and tectonic background. Methods: Samples for major and trace element analysis were first crushed and ground to a particle size of less than 200 mesh. The oxides of major elements were measured by X- ray fluorescence spectrometry. The trace and rare earth elements were determined with an XⅡ Series ICP- MS. For rare earth elements content analyses, 50 mg samples were precisely weighed and reacted with 1 mL HF and 0.5 mL HNO3 in screw top PTFE- lined stainless bombs. The analytical precision was better than 5%. Prior to n(87Sr)/n(86Sr) and n(144Nd)/n(143Nd) analysis, 50 mg of sample powder was weighed. The powder was then leached using 1.0 mol/L acetic acid to dissolve the carbonate fraction. After this step, Sr and Nd were separated and purified by conventional cation- exchange resin method respectively. Isotopic ratios of obtained Sr and Nd solutions were measured on a thermal ionization mass spectrometer (Triton, MAT261). The measured isotopic ratios were corrected for mass fractionation using n(86Sr)/n(88Sr) = 0.1194 for Sr and n(146Nd/n(144Nd) = 0.7219 for Nd. The Sr standard NBS SRM 987 yielded n(87Sr)/n(86Sr) = 0.710244 ± 4 (n = 10, 2σ), while the Nd standard JNDi- 1 gave n(143Nd)/n(144Nd) = 0.512124 ± 2 (n = 20, 2σ). All analyses were performed at the Mineral Resources Supervision Testing Wuhan Centre of China Land & Resources Ministry. Results and conclutions: Major elements of the rocks shows that the meta- basalts belong to tholeiitic basalt characterized by rich in sodium and poor in potassium; rare- earth element differentiation is not obvious, trace elements are deficient in Ba, Th, and P, and high field strength elements are not deficient. the values of εNd (t) are all positive, similar to the mid- oceanic ridge basalt (MORB).

Abstract:Objectives: A lot of intrusives are located in the subduction—collision—accretion complex belt, which formed in 450~440 Ma, between the east and west Wuyi massif. The study of the geochronology of these intrusives is significant for defining the age of collision between east and west Wuyi massif and the convergence of Wuyi blocks, and also plays a certain role in promoting our understanding of the formation and emplacement of the Caledonian granitoids in South China. Methods: The Xiayuan and Hongyegang intrusives in Dikou area are typically developed in the subduction—collision—accretion complex belt. In this paper, the zircon LA- ICP- MS U- Pb dating method is used to make a detailed geochronology of the intrusives in this area. Results and Conclusions: Three rock samples taken from the Xiayuan granitic pluton in Dikou area were dated by zircons La- ICP- MS U- Pb technique, which show that the emplacement crystal ages of the Xiayuan intrusives were 420±4 Ma, 430±4 Ma and 434±4 Ma, respectively. It indicates that the Xiayuan granitic pluton is Caledonian intrusives, rather than Indosinian granite by the previous understanding. The zircon U- Pb age in Hongyegang granite was 398±4 Ma, indicates that the Hongyegang granite is a late Caledonian intrusives rather than Yanshanian granite. Combined with the analysis of the latest research results in Wuyi Mountain area, we suggest that the Xiayuan and Hongyegang intrusives in Dikou area may be formed in the extensional rift environment after the collision between the east and west Wuyi massif. The obtained emplacement ages of the Xiayuan and Hongyegang intrusives in Dikou area provide precise constraints for the Caledonian tectonic evolution of the Wuyi Blocks.

Abstract:Objectives：This paper provided petrography, LA- ICP- MS zircon U- Pb age and geochemistry of the monzogranite in Ajinguole area of Zalute Banner, Inner Mongolia, and discussed the formation age, genesis and geological significance of the rocks. Methods：Two fresh samples were collected for analyzing the whole- rock main and trace elements in Ajinguole area of Zalute Banner. They were also selected to carry out the zircon U- Pb dating by LA- ICP- MS method. Zircon U- Pb isotope ages of selected samples were performed in the State Key Laboratory of Geological Processes and Mineral Resources, China University of Geosciences (Beijing). During the period, data were processed and plotted by ICPMSDataCal program developed by Liu Yongsheng (2008) and Isoplot program developed by Kenneth R. Ludwig (1999). Common lead was corrected according to Anderson (2002), and the contents of Pb、U and Th in zircon samples were calculated using NIST612 as external standard. The determination of major elements, trace elements and rare earth elements in chemical analysis samples was completed in Beijing Research Institute of Uranium Geology. The melting method of XRF fluorescence spectrometer was used for precise analysis of the major elements in rocks. The content of trace rare earth elements in the whole rock was determined by ICP- MS. Results：Based on the study of occurrence characteristics, microscopic characteristics and geochemical characteristics, the emplacement age was determined and its genesis and tectonic background were discussed. The results show that the U- Pb weighted ages of zircons in the monzogranite are 124±1 Ma and 126±1 Ma, respectively. The content of SiO2 in the monzogranite is 69. 45% to 73. 64%, Na2O and K2O are 3. 16% to 4. 62%, 3. 78% to 4. 37%; Al saturation index A/CNK is between 1. 00 to 1. 25. At the same time, the trace elements such as K、Ba、Rb and other large ion lithophile elements, incompatible elements such as Zr、Th、U、Hf, show enrichment state, on the contrary, high field strength elements such as P、Ti、Nb、Ta, are seriously depleted. Conclusions：The intrusive age of the rocks was the Early Cretaceous. It belongs to I- type granite with high potassium calcium, alkaline peraluminous with high differentiation, which has the genetic characteristics of subduction zone. Considering the background of regional tectonic evolution, we consider that the extension of Zalute Banner in the southern segment of the Da Hinggan Mts. was mainly related to the extensional collapse of the Mongolian—Okhotsk orogenic belt.

Abstract:Objectives: This study targets on trace element in zircon as a breach to elaborate the petrogenesis and differentiation features of the Wangxianling granitoid in southern Hunan Province, Nanling Mountains, on the basis of field work and zircon U- Pb geochronology and Hf isotopes. Methods:The microscope observation of rock sample was conducted based on field work with subsequent zircon U- Pb dating, trace element measurement and Nd—Hf isotopes analysis. Results: The zircon U- Pb dating yielded the age of 2378±35 Ma for coarse grained tourmaline—muscovite granite. The two- mica granite emplaced at 2366±5 Ma and altered tourmaline granite age was constrained at 2385±35 Ma. And their εHf(t) values are confined as -118~-78、-178~-74、-161~-63, and εNd(t) values of -99~-111、-108~-111、-92~-108 respectively. Zircon trace element of the tourmaline—muscovite granite shows the REE reaches 1392×10-6~2184×10-6 with negative Eu anomaly（Eu/Eu*=010~018）and significant positive Ce anomaly(Ce/Ce*=664~6879). Besides, it contain high P and Y contents ranging from 735×10-6~1390×10-6 and 1931×10-6~3024×10-6 respectively. The Ta and Th contents are confined between 84×10-6~217×10-6 and 461×10-6~2137×10-6 respectively. In comparison, two mica granite show lower LREE and more prominent negative Eu anomaly(Eu/Eu*=003~011) and weaker Ce anomaly(Ce/Ce*=154~775). The Y content is higher (3470×10-6~4698×10-6) and P content (1777×10-6~2653×10-6) are higher and Ta(620×10-6~1726×10-6) and Th (133×10-6~360×10-6) contents are lower. Conclusions: The Wangxianling granitoid is compounded with Late Triassic intrusions, namely the tourmaline—muscovite granite, the two- mica granite and altered tourmaline granite. Their εHf(t) and εNd(t) values overlap with each other and they are product of a same magmatic event. Zircon trace element shows the increase of Ce/Sm—Yb/Gb ratios and low Y and P content of the tourmaline—muscovite granite which suggests there is MREE and Y- bearing mineral such as apatite fractionation. On the other hand, two- mica granite was depleted of LREE and Th relative to tourmaline—muscovite granite which indicates its melt experienced LREE and Th- enriched minerals such as allanite and monazite saturation and the high P content further imply that it’s allanite instead of P- enriched monazite. The low Nb, Ta content and more prominent negative Eu anomaly indicate rutile and feldspar fractionation. The tourmaline—muscovite granite and two- mica granite are contemporary and originated from the same source region, yet zircon trace element tells the distinct crystallization processes. This study suggests accessory mineral chemistry could effectively reveal differentiation and crystallization sequences of its host magma.

Abstract:Objectives: Qimantage is located in the western part of the East Kunlun belt. The study of the Late Triassic igneous rocks in this area not only helps to understand of the Indosinian tectonic—magmatic evolution history of the East Kunlun orogenic belt, but also can provide constraints for the subduction and the closing time of the Paleo- Tethys Ocean. Methods: Detailed geological survey, LA- ICP- MS zircon U- Pb dating of monzogranite, whole rock geochemical and Nd—Pb isotopes analysis of igneous rocks in eastern Qimantage, East Kunlun orogenic belt. Results: The zircon U- Pb dating of the monzogranite in southern Ketinghaer is 219.8±0.5 Ma, combining previous ages it can be ascertained that the igneous rocks are the products of Late Triassic magmatic activities.The whole- rock geochemical analyses show that the Late Triassic igneous rocks in eastern Qimantage lie in high K calc- alkaline fields, the Aluminium saturation index show the metalumininous and weak peraluminous features,integrated with enrichments of LREE and LILE（Rb, Th, K, etc.）, depletions of Nb, Ta, P and Ti（HFSE）and obvious Eu negative anomaly, suggesting plate subduction- related geochemical affinities. Granites and rhyolites have similar Nd and Pb isotopic compositions.The εNd(t) of granites range from -4.66 to -4.53,the model age of depleted mantle range from 1363 Ma to 1375 Ma. The εNd(t) of rhyolite is -4.63, and the TDM2 is 1368 Ma. Projection points in n(143Nd)/n(144Nd)—n(206Pb)/n(204Pb) diagram and Pb isotopic compositions diagrams are located near the upper crust and EMII mantle regions. Conclusions: The Late Triassic granites and rhyolites in eastern Qimantage are closely related to their spatial distribution with similar formation time and similarity or consistency in major—trace elements and Nd—Pb isotopic compositions. Therefore, the authors believe that they are the products of homologous magma in the same period and tectonic environment. Combining achievements of predecessors with this study, it’s believed that the East Kunlun region was in the active continental margin arc environment during plate subduction, and the Paleo- Tethys Ocean was not completely closed in that period.

Abstract:The deposits related to granites are mainly magmatic—hydrothermal ores, of which their time—space distribution and genesis display great intimacy with the associated granites. Whether it can exsolve hydrothermal fluids during magmatic melting and what quantity of exsolutions it can provide is becoming a necessary prerequisite that constrain granitoid mineralization. Based on the previous researches and study here, this paper systematically summarizes that granite related to mineralization develop petrological structure of unidirectional solidification texture (UST), quartz eyes, miarolitic cavities and snowball texture in the exsolution and saturation of magma volatile phase. Contribution of magmatic chemical composition to the evaluation of ore potential of granites based on elemental geochemical behavior and physical—chemical conditions. The halide content in volatile components and the abundance of major elements cannot be used as discriminative indicators of mineralization potential, while trace elements are geochemical fingerprints that identify the ore potential of granites. The characteristics of high field strength elements and rare earth elements showing changes in system geochemical behavior are expected to be the best indicators of mineralization potential. These informations provide theoretical guidance for the metallogenic prediction and prospecting evaluation of magmatic—hydrothermal polymetallic deposits. Moreover, this paper also presents the problems in the study and points out the work that needs to be done in in near future.

Abstract:Collapse column is a common geologic hazards in coal mining. The accurate detection of the collapse column has always been the focus of safety production research in coalfields. It is difficult to meet the demand of fine exploration in coalfields by relying on conventional PP- wave seismic exploration technology. Both PP- and PS- wave data can be obtained in multiwave seismic exploration, which can provide more wavefield information. Moreover, PS- wave has higher resolution for some small structures in the shallow layer, so making full use of multicomponent seismic data can effectively improve the accuracy of seismic exploration. In this paper, multiwave seismic technology is applied to the collapse column in coal seam, where multiwave seismic numerical simulation study is performed for collapse column in coal seam. The elastic finite- difference method is used for multicomponent forward modeling of collapse column model, and then the prestack depth migration imaging is performed on the separated PP- and PS- waves. Multiwave seismic numerical simulation tests of two small collapse column models show that multiwave seismic exploration technique is an effective detection method for collapse column in coal seam. It is helpful to find out the collapse column structures in coal seam and obtain better exploration effects using multicomponent seismic data.

Abstract:Objectives: Sichuan Basin is considered to be one of the most representative continental basins of Cretaceous in China. But there is no evidence of the relevant terrestrial biostratigraphy. In order to understand the characteristics of sporopollen assemblages of the Early Cretaceous red beds in Sichuan Basin and to determine the stratigraphic age and the paleoclimate characteristics of the Cangxi Formation and the Bailong Formation. Methods:The sporo and pollen are separated from the samples by conventional acid treatment and heavy liquid method. Diversity atatistics were also carried out. Results: The Early Cretaceous Classopollis pollen was the first discovered in the Mumen area of Cangxi County, northern Sichuan Basin. It is characterized by a strong dominance of Classopollis pollen and a low diversity of other palynomorphs, exhibits a very high abundance of Classopollis pollen, reaching up to 97%. The palynological assemblage is dominated by gymnosperm pollen, which is followed by fern spores; no angiosperm pollen was observed. The spore assemblage is dominated by CyathiditesandDeltoidospora (averaging 14%),followed by Osmundacidites (average 08%). Conclusions:Although Dicheiropollis has a low abundance of fossils, its stratigraphic distribution data show short- term and sub- layout limits. It is indicated that the Cangxi Formation and the Bailong Formation of the Wall Rock Group in northern part of the Sichuan Basin may be in the Valanginian to Hauterivian Period. According to the genetic relationship of the main sporopollen assemblages, the Sichuan Basin was dominated by a single forest community dominated by Cheirolepidiaceae and a small number of dwarf plants. Arid climate prevails. Based on the discovery of Dicheiropollis. The boundary between the Southeast China Classopollis—Schizaeoisporites Province and the Xizang—Tarim Dicheiropollis Province is moved at least to the east of Sichuan Basin. This indicates that it is likely that the phytogeographic regions along the Paleotethys Ocean are wider than the regions proposed in earlier studies.

Abstract:Objectives:The giant grained uraninite found in Muding area, Yunnan Province, is very rare in the world and there is a very special “uraninite—rutile(mass)—zircon(small amount)” mineral assemblage. The genesis of uranium mineralization and the formation mechanism of the giant grained uraninite like puzzles have plagued the uranium geologists for many years. Methods:In recent years, we have carried out comprehensive studies，including petrology, mineralogy, petrogeochemistry, isotopic geology and chronology. Results:It is confirmed that the uranium- riched rock is albitite, which mainly composed of albite(average An=3.36).The average Na2O content of the albitite is 10% and belongs to alkaline and strong peraluminous rock. albitite has characteristics of high DI (average is 82.39%) , high FL(average is 88.39%) , high FM(average is 84.92%) , low SI(average is 5.06%) and very low ∑REE content(average∑REE is 162). The \[n(87Sr)/n(86Sr)\]iof albitite＞0.710; zircon age of albitite（SIMS） is 1057 Ma, close to the age of Shuiqiaosi rock(1038~1070 Ma). The REE patterns of uraninite are consistent with magmatic uranium deposits ,which is formed in high temperature geological environment(about 662.19℃). Conclusions:Albitite is the farthest product of Shuiqiaosi highly fractionated rock from biotite microcline granite— biotite microcline albite granite— albite granite— albitite. The uraninite and albitite have the characteristics of homology, Co- evolution and close to simultaneous formation, and then confirm the uranium mineralization in the Muding area is a new type relation to albitite and has the genesis characteristics of rock fractionation. Ti plays a crucial role in the U complexation, migration and formation of giant grained uraninite. In addition,in the process of evolution and fractionation of Shuiqiaosi rock ,not only the occurrence of uranium mineralization is controlled, but also the occurrence of Nb and Ta mineralization in the stage of albite granite.

Abstract:Objectives: Tuff was developed in the Lucaogou Formation in the Jimsar Sag, Junggar Basin. And the tuff matter plays an important role in the formation of shale oil, and its development interval is also the best oil- bearing interval of shale oil. Therefore, the study of distribution of tuff matter and its relationship with the hydrocarbon generation of organic matter is of great significance for the understanding of oil and gas accumulation rules of the Jimsar shale oil. Methods: Based on evaluation source rocks and analysis its sedimentary environment, combining study of diagenetic minerals that have a genetic relationship with hydrocarbon activities, the controlling factors and hydrocarbon generation mechanism of the formation of high- quality shale oil source rocks of the Lucaogou Formation in the Jimsar Sag were discussed. Results: Qualitative analysis of source rocks indicate that muddy dolostone is main source rock of Lucaogou Formation in Jimsar Sag. The source rock has high abundance of organic matter and good hydrocarbon generation potential, type of organic matter is mainly type I and type II1. The source rock is inmature stage, with Ro value is between 0.6% and 1.1%, and C29αααS/(S+R) ratio is between 03 and 05. Distribution of regular sterane C27, C28 and C29 in source rocks of Lucaogou Formation is C27

Abstract:Objectives:The Hongshanzi complex intrusives located in the northeastern part of the Guyuan—Hongshanzi uranium belt, which is composed of early Late Jurassic alkali feldspar granite,biotite granite and early Cretaceous early fine- grained biotite granite and granite porphyry. The composition of the rock is dominated by the alkali- feldspar granite and biotite granite in the early Jurassic. The early Late Jurassic biotite granites include medium—fine- grained biotite granites and porphyritic biotite granites, At present, uranium mineralization has been found in the inner and outer contact zone between the Early—Late Jurassic mid—fine- grained biotite granite and the Late Jurassic volcanic rock in the compound rock body, indicating that this zone is a favorable place for further uranium exploration. However, the geochemical characteristics of the Late Jurassic alkaline feldspar granite and biotite granite that make up the Hongshanzi complex rock mass have not been systematically studied, which restricts the in- depth study of uranium mineralization. Methods:Based on detailed observations of occurrence of Hongshanzi complex rock mass in the field, we have studied the petrology, geochemistry, Sr—Nd—Pb radio isotope and O isotope of these biotite granite to discuss nature of source region and tectonic setting, than, we have discussed the relationship between biotite granite and uranium mineralization. Results:All of biotite granite are characterized by high SiO 2 (75. 2%~76. 6% and 74. 6%~75. 3%, respectively), (K 2O+Na 2O) (8. 19%~8. 96% and 8. 78%~9. 10%, respectively), and K 2O/Na 2O (1. 19~1. 39 and 1. 29~1. 35, respectively), low Al 2O 3 (11. 5%~12. 3% and 12. 5%~12. 7%), CaO (0. 30%~1. 24% and 0. 76%~0. 83%, respectively). It does not contain standard mineral corundum, indicating that the magma source area is magmatic rock; FeOT is 1. 79%~2. 13% and 1. 80%~1. 91%, respectively, both greater than 1. 00%, with iron- rich characteristics of A- type granite; zircon saturation temperatures are 834~869℃ and 819~839℃, greater than 800℃, with the high- temperature characteristics of A- type granite. The contents of Al 2O 3 are 11. 5%~12. 3% and 12. 5%~12. 7%, respectively. A/CNK are 0. 90~0. 97 and 0. 93~0. 96, respectively. Enrichment of large ion lithophile elements Rb, Th, K, etc. and high field strength elements Zr, Hf, Nd, Ta, Y, etc. Loss of large ion lithophile elements Ba, Sr, etc. (Zr+Nb+Ce+Y) are 897×10 -6 ~1236×10 -6 and 513×10 -6 ~643×10 -6 , both of which are greater than 350×10 -6 , and the values of 10 4 *Ga/Al are 6. 28~6. 90 and 3. 28~3. 98, respectively, greater than 2. 6, with trace element characteristics of type A granite, which is the product of the intraplate tensile structure. Their lower n( 87 Sr)n( 86 Sr) i, higher εNd (t) , younger T DM2 , lower n( 206 Pb)n( 204 Pb) i, n( 207 Pb)n( 204 Pb)i, n( 208 Pb)n( 204 Pb) i and lower δ 18 O V-SMOW . Conclusions:The results indicates the magma originated from the partial melting of the young lower crust by type EMⅠ mantle- derived basic magma bottom infiltrating the lower crust, and experienced high- temperature hydrothermal alteration. The U content of medium—fine- grained biotite granite and porphyritic biotite granite is 7. 3×10 -6 ~22. 3×10 -6 (average 14. 6×10 -6 ) and 4. 53×10 -6 ~6. 90×10 -6 (average 6. 01×10 -6 ), especially the uranium mineralization has been found in the inner and outer contact zones of the former and the Late Jurassic volcanic rocks, which is a favorite part for deep exploration of uranium deposits.

Abstract:Objectives:The distribution of selenium in different regions and different layers of soil is uneven. The development of different natural selenium- enriched foods based on local selenium- enriched soil clues is an important direction for the development of local characteristic agricultural research. According to the data of 1∶250000 target geochemical surveys in Yunnan Province and 1∶50000 four regional geological surveys in Yunnan, the surface soil in Yunnan Province is relatively lean in selenium, but in the Yimen Pujia Village—Tongchang township—Xishan Village—Shizishan—Lufeng tuguan town,There are about 400 km2 of selenium- enriched soil in the local low mountain . Results: The average selenium content of soil is 0.54 μg/g, and the selenium content of local soil is 136 μg/g. The profiles show that the selenium element exhibits the phenomenon of surface aggregation. Selenium is larger than the deep soil in the topsoil, while the selenium content in the deep soil is larger than that in the parent rock. Conclusions:The selenite content of different bedrocks shows carbonaceous slate. It is larger than argillaceous slate and larger than silty slate, which is positively correlated with carbonaceous, clayey and muddy. According to this clue, a large number of natural selenium- enriched wild mushrooms and vegetables were newly discovered in the local area. Preliminary studies have shown that the formation of local selenium- enriched soil is related to the specific geological background, while the soil environment for producing natural selenium- enriched wild mushrooms and vegetables is relatively superior.

Abstract:The first popular science award of Geological Society of China announced

Abstract:“The 2019s’ Top 10 Geoscientific Achievments”and “the 2019s’ Top 10 Prospecting Results” of Geological Society of China issued

Abstract:The work related to “Geological culture village (town)” assessment and licensing, “natural selenium-rich land” identification and logo management launched soon

Abstract: