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Copyright of Uranium Geology is the property of Uranium Geology Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In the middle and western part of Xihu Depression, East China Sea Basin, many wells have encountered thick basement volcanic rocks, it shows the great potential of buried hill exploration. But for a long time, the development stage of basement volcanic rocks is not clear, the basement formation age and stratigraphic sequence are not clear, which restricts the early structural evolution of Xihu Depression and the exploration potential analysis of buried-hill reservoir. This time, by means of petrology, geochemistry, structural geology, geophysics and other multidisciplinary methods, a comprehensive study and evaluation of the bedrock in the central and western part of Xihu Depression in the East China Sea Basin is carried out to determine the formation age, rock types and stratigraphic sequences of the basement of the Xihu Depression, summarize the new understanding of temporal and spatial evolution characteristics of basement. New understanding of temporal and spatial evolution of basement, which is helpful to clarify the division of the early tectonic evolution stages of the Xihu Depression and the lithology distribution of the buried hills in the basin. It indicates the favorable distribution area of basement buried hill reservoir of Xihu Depression, provides the direction for the exploration of buried hill in Xihu Depression. [ABSTRACT FROM AUTHOR]

Copyright of Petroleum Geology & Oilfield Development in Daqing is the property of Editorial Department of Petroleum Geology & Oilfield Development in Daqing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In order to understand the tectono-magma events in the southern margin of Altun in Early Neoproterozoic, the Yaganbuyang granitic gneiss in Mantelike area was selected for detailed studies of petrology, isotope chronology and petrochemistry. The results show that Yaganbuyang granitic gneiss is formed in Neoproterozoic Qingbaikou period, and the zircon U-Pb age is(880.3±3.4) Ma; the rock with obvious fractional distillation of LREE and HREE and the loss of HFSEs such as Nb,Ta,Zr and Hf, is magnesian granite in the peraluminous and calc-alkaline series, and has the characteristics of crustal remelting granite, which originates from the partial melting of base rock in the amphibolite facies of the lower crust and forms in the syn-collisional granite zone. It is suggested that the tectono-magma events in the southern margin of Altun has the possiblity of matching to the assemblage events of Rodinia supercontinent in Neoproterozoic, indicating that assemblage collision occurs between Tarim and Qaidam plates at the early time. [ABSTRACT FROM AUTHOR]

The Carboniferous Yanghugou Formation in the western margin of the Ordos Basin is found to have good source rocks with high organic matter content and good prospects for exploitation. The original stratigraphic division is controversial, and it is difficult to meet the growing demand for exploration. Taking the Xiaheyan section in Beishan area of Weining as an example, through field measurement, geochemical element detection, paleontological detection, the Yanghugou Formation was finely divided to determine the stratigraphic division marker bed in the southern section of the western margin of the basin. The boundary between the Yanghugou Formation and the Taiyuan Formation was redefined, and the boundary between the Carboniferous and the Permian was taken as the boundary between the Yanghugou Formation and Taiyuanzu. According to the sporopollen distribution characteristics, the Yanghugou Formation was divided into three sporopollen belts from bottom to top:Lycospora noctuina-Cyclogranisporites aureus combination,Dictyotriletes bireticulatus-Ahrensisporites guerickei-Torispora securis combination,Crassispora kosankei-Densosporites anulatus combination. The geochemical characteristics show that the Mn/ Fe value increases and the - δ13 C value decreases during the Yanghugou Formation period, and the sea level rose during this period. In the Taiyuan Formation, the Mn/ Fe value decreases and the - δ13 C value increases, and the sea level decreases during this period. Based on this, the Yanghugou Formation was divided into three segments: Yang 3, Yang 2 and Yang 1 from bottom to top. Through the combination of geochemical characteristics and sedimentary characteristics, the division of third-order cycles was determined to further verify the lithospheric division. . By establishing regional stratigraphic comparison sections, the depositional characteristics of large stratigraphic thickness in the western part of the work area and small in the eastern part were demonstrated, and there were obvious differences in the distribution and development of the stratigraphy of the Yanghugou Formation and each small layer within its group in different areas. [ABSTRACT FROM AUTHOR]

Copyright of Uranium Geology is the property of Uranium Geology Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Acta Geoscientica Sinica is the property of Acta Geoscientica Sinica Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Natural Gas Industry is the property of Natural Gas Industry Journal Agency and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The Grove Mountains are considered as inland continuation of Prydz belt in East Antarctica, and could provide important constraints for the tectonic nature of Prydz belt. Most of the basement in Grove Mountains is hidden beneath the ice sheet, the sparse exposures of bedrocks are insufficient to fully show the geological characteristics of the entire Grove Mountains. A number of moraine belts exposed on the glaciers of Grove Mountains may carry information about the geology of Grove subglacial highlands in greater scope and depth, and play an irreplaceable role in revealing the material composition and tectonic evolution of Grove Mountains. The types and distribution characteristics of glacial moraines in Grove Mountains were summarized, and the study on petrology, isotopic chronology and zircon Hf isotopic analysis of the glacial moraines in Grove Mountains in the recent decades was reviewed. The subglacial highlands are more complex in composition to the exposed bedrock in Grove Mountains, which only experience a single Pan-African metamorphic cycle. The wide distribution of high-pressure granulites suggests that at least part of Grove subglacial highlands undergo Pan-African high-pressure granulite facies metamorphism. In contrast with Prince Charles Mountains-Prydz Bay region, the Grove subglacial highlands have earlier metamorphic ages and higher degree of metamorphism, suggesting that the collision suture of Prydz belt should lie to the south of Grove subglacial highlands. [ABSTRACT FROM AUTHOR]

The Zhuxiling W-polymetallic deposit in the southern Anhui is located at the eastern margin of Jiangnan paleocontinent, the rock closely associated with the mineralization is the granodiorite. The petrographic, mineralogical and petrogeochemical studies on the granodiorite were carried out. The results show that the granodiorite has moderate contents of SiO2(64.67%-67.33%), Al2O3(15.26%-16.26%)and MgO(1.09%-1.37%), the ratio of K2O/Na2O is higher than 1.1 with the A/CNK ratio of 1.00-1.04, indicating that the granodiorite belongs to high-K cal-alkaline series and weakly peraluminous series; the granodiorite shows enrichment of Rb, K, and depletion of Nb, Ta, Zr and Ti, the total contents of REE are(90.40-166.94)×10-6 with the ratios of LREE/HREE(7.15-15.16)and(La/Yb)N(11.60-37.32), the chondrite-normalized REE pattern displays a characteristic listric-shaped REE profile; the whole-rock zircon saturation thermometer and the chemical composition of biotites in the granodiorite indicate that the diagenetic temperatures range from 720 ℃ to 780 ℃, and the diagenetic pressures range from 73 to 169 MPa with corresponding emplacement depth varying from 2.75 to 6.39 km, and the calculated oxygen fugacity varies from -17.52 to -10.09. Collectively, the granodiorite belongs to I-type granitic rock, which is formed in the moderate-high temperature, water-rich and oxidized environment, and it is likely related to the previously proposed EW-trending slab-window that caused by the rupture of the subduction of paleo-Pacific plate [ABSTRACT FROM AUTHOR]

Copyright of Journal of Central South University is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The low-temperature high-pressure (LT-HP) metamorphic belt in central Qiangtang is the largest high-pressure metamorphic belt occurring in Qinghai-Tibet Plateau, and is an important window for understanding the early formation and evolution of Qinghai-Tibet Plateau. The high-pressure metamorphic belt is mainly exposed along Longmu Co-Shuanghu suture zone, and is composed of phengite schists, blueschists, eclogites and so on. Among these high-pressure rocks, the eclogites in central Qiangtang are found in Pianshishan, Guoganjianian Mt., Gemu and Gangma Co, and occur as lenses, blocks and layers in phengite schists or metasediments. Based on the available data, the mineral assemblage of the peak eclogite-facies stage of eclogites in central Qiangtang is garnet+omphacite+phengite+rutil±glaucophane±quartz.The pseudomorphs of box-shape epidote+paragonite found in garnet and P-T results from traditional geothermobarometers indicate that they have reached the lawsonite eclogite-facies metamorphism. Although some eclogites preserve the evidence of suspected ultra-high pressure metamorphism, such as the quartz lamellae exsolves from omphacite, the rutile, quartz or amphibole exsolve from garnet, and the rutile exsolves from apatite, there is no typical ultra-high pressure indicator mineral (such as coesite, diamond, etc.) in the eclogites. "The ultra-high pressure indicator" from garnet compositions and P-T recalculation using traditional geothemobarometers indicate that the eclogites in central Qiangtang do not undergo the ultrahigh-pressure metamorphism. The eclogites in central Qiangtang have a retrograde P-T path characterized by the isothermal decompression, and experience several stages of retrograde metamorphism. [ABSTRACT FROM AUTHOR]

Triassic magmatic rocks widely develop in the conjunction of Qinling, Qilian and Kunlun orogens along Nanshan fault, Wahongshan fault and Duohemao fault in Qinghai with a NW-SE-trending. The types of rocks are complicated and various, including volcanic and intrusive rocks. Volcanic rocks consist of basalt, andesite, dacite, rhyolite and volcanic breccias; intrusive rocks consist of gabbro, diorite, granodiorite, granite and quartz porphyry, etc. Isotopic chronology research reveals that the forming ages of these Triassic igneous rocks are mostly concentrated in Early-Middle Triassic (233-253 Ma) and Late Triassic (205-225 Ma), and gradually decreased from NW to SE. Geochemistry characteristics and rock assemblages suggest that the Early-Middle Triassic magmatic rocks in the conjunction of Qinling, Qilian and Kunlun orogens are formed in continental margin arc setting by the northern subduction of Palaeo-Tethys ocean; however, the Late Triassic magmatic rocks are formed in post-collisional stage. [ABSTRACT FROM AUTHOR]

Continental dynamics is presented and defined on basis of research advances of modern plate tectonics. It emphasizes that continent is going in an independent dynamic system. Continental dynamics focuses on fundamental issues of continental formation and evolution and its dynamic mechanism in continent scale, and further clarifies relation between continent and whole earth’s system. Here we insist a research field of vision that continent is evolving. Continental rocks record materials on the earth from earliest up to now, and hereafter tectonic imprints on them. Therefore, the study on continental material evolution is a key to understand continental dynamics. This paper is a part of results of “slab structure and continental dynamics strategic research” project supported by National Natural Science Foundation of China and Academic Division of Chinese Academy of Sciences. [ABSTRACT FROM AUTHOR]