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This paper deals with the sedimentation records of POPs such as OCPs and PCBs in sediments along the cross section of flood plain of Gangjiang River so as to determine the history of organic pollution. Classification of molecular stratigraphy was carried out on the basis of the evolution of the concentration of organic compounds, which indicates that there exist high concentrations of residual HCHs, DDTs and PCBs at the depth from 26 to 46 cm, with high level of residual DDTs being found even in deeper areas. Although the concentrations of residual OCPs and PCBs do not exceed the contamination standard, special attention should be paid to the potential release of such pollutants to the surrounding environment. The sedimentation records of POPs are consistent with the development history of Ganjiang River and hence such studies contribute to the study of the age of contemporary sediments.

Yu Y.-S.,Key Laboratory of Nuclear Resources and Environment ECIT | Yang Z.-S.,Chinese Academy of Geological Sciences | Tian S.-H.,Chinese Academy of Geological Sciences | Gao Y.,Jiangxi Institute of Geological Survey | And 2 more authors.
Geology in China | Year: 2015

The Ri' a copper-polymetallic deposit, as a typical representative copper metallogenesis of the Nixiong orefield and an important part of Cuoqin-Shenzha iron-copper metallogenetic belt, is located in the middle north of Gangdise. The authors analyzed the mineral composition, major elements, trace elements, and U-Th-Pb composition of zircon from biotite granite associated with copper mineralization in the Ri' a copper polymetallic deposit by LA-ICP-MS. The results show that the biotite granite has typical characteristics of I-type granite, belongs to shoshonite series and must have originated from a crustal-mantle provenance. Zircon U-Th-Pb dating yielded 206Pb/238U age of (89.9±1.6)Ma, which is consistent with the age of mafic intrusive in the Ri' a copper-polymetallic deposit. Combined with the results of previous studies, the authors hold that the bimodal magmatism of Early Late Cretaceous was closely related to mineralization of the Ri' a copper-polymetallic deposit. In consideration of the tectonic environment, the authors propose that the magmatism was controlled by the subduction of both Bangong Co-Nujiang ocean crust and Brahmaputra ocean crust.

Tang J.-X.,Chinese Academy of Geological Sciences | Zhang Z.,Chengdu University of Technology | Li Z.-J.,Chengdu University of Technology | Sun Y.,Chengdu University of Technology | And 5 more authors.
Acta Geoscientica Sinica | Year: 2013

Located in the south of western Bangong Co-Nujang River metallogenic belt of north Gangdise, the Ga'erqiong-Galale copper-gold ore field possesses lots of ore body types (porphyry type, skarn type and iron oxide-copper-gold type) and high gold grade (up to 205 g/t) and unique structural position, thus having great research significance. According to systematic summary of ore concentration areas and systematic analysis of data, the authors identified ore characteristics, found a large number of native gold and intermetallic compounds, and summarized the metallogensis. It is considered that metallization was mainly associated with emplacement of quartz diorite and granodiorite in the late phase of Yanshanian period, the evolution time between diagenesis and mineralization was about 1 Ma, and the mineralization in the area was characterized by the vertical zoning of copper-gold in the upper part and molybdenum in the lower part. S, Pb isotopes suggest that the metallogenic material had characteristics of crust-mantle mixing. During the emplacement and fractionation evolution of metaluminous-weak peraluminous calc-alkaline-high-K calc-alkaline magmatite, the porphyry-skarn type copper-gold-molybdenum ore bodies were formed in the area of pluton uplifting and along the contact zone between the pluton and the Cretaceous carbonate, whereas iron oxide-copper-gold type ore bodies were formed at the edge of pluton's tectonic fracture zone (F1 fault). On such a basis, the authors have established the porphyry-skarn-iron oxide-copper-gold type "three-position" mineralization deposit model of magmatite- strata-ore-controlling structure. Based on these data, the authors indicate the prospecting direction in search for new ore bodies in the ore field.

Gao L.-Z.,Chinese Academy of Geological Sciences | Ding X.-Z.,Chinese Academy of Geological Sciences | Liu Y.-X.,Chinese Academy of Geological Sciences | Huang Z.-Z.,Nanjing Center | And 5 more authors.
Geological Bulletin of China | Year: 2013

Zircon ages (825 Ma±5 Ma) and (830 Ma±6 Ma) of tuff in the Chentangwu Formation are reported for the first time from the "Pingshui Group" in Pujiang County, Zhejiang Province. In combination with the SHRIMP U-Pb age (824 Ma±5 Ma) of the tuff from the Xiushui Formation and 825 Ma±5 Ma of the rhyolite from Xingzi complex Group and the SHRIMP U-Pb age 840 Ma±6 Ma of the spilite, the U-Pb ages of the rhyolite (833 Ma±4 Ma and 831 Ma±3 Ma) in the Shaoqiwa Formation of the Lushan Mountain in the north part of the Jiang-Shao fault zone, the Chentangwu Formation should be located below the Wuling Movement at 820 Ma and just above the Zhangcun Formation of the Shuangxiwu Group, not belonging to the traditional Pingshui Group. The authors consider that the Mengshan Formation, which is below the Chentangwu Formation, is correlated with the lava pillow and spilite of the Shaoqiwa Formation in Lushan area. The reconfirmed age of the Chentangwu Formation is of important significance for the stratigraphic correlation and tectonic evolution study in the Jiang-Shao fault zone.

Gao L.-Z.,Chinese Academy of Geological Sciences | Huang Z.-Z.,Jiangxi Institute of Geological Survey | Ding X.-Z.,Chinese Academy of Geological Sciences | Liu Y.-X.,Chinese Academy of Geological Sciences | And 2 more authors.
Geological Bulletin of China | Year: 2012

Zircon dating of tuff bed in the Xiushui Formation of the Shuangqiaoshan Group has yielded an age of 824 Ma±5 Ma, with MSWD equal to 1.3, and there are three groups of zircon U-Pb ages for the Majianqiao Formation, of which, one is identical with the age of the Xiushui Formation (824Ma±5Ma, MSWD=1.9), and the youngest age is 769Ma±8Ma (MSWD=0.55). In combination with the SHRIMP U-Pb dating of the tuff bed of the Shuangqiaoshan Group in the eastern part of the Jiangnan oregen, the data of the Fanjingshan and Xiajiang groups in the western part and some ages of the Lengjiaxi and Banxi groups, the authors hold that the Shuangqiaoshan Group should belong to Neoproterozoic strata below the Wuling Movement. According to the isotopic data, the Majianqiao Formation should be assigned to the sedimentary strata of the Banxi stage. These ages are very important for regional stratigraphic correlation of the corresponding period and tectonic evolution. The zircon U-Pb ages mentioned above demonstrate that Neoproterozoic strata were developed around the age of 820 Ma in northwestern Jiangxi Province. The results obtained also influence the stratigraphic subdivision and correlation of the metamorphosed rocks in whole Jiangnan old land and help geologists solve the problem of geological background and ore-forming conditions of the Jiangnan orogen.

Li B.,Hunan Institute of Geological Survey | Li B.,Hubei University | Xiang S.-Y.,Hubei University | Feng D.-X.,Geothermal Geological Survey Party | And 3 more authors.
Geological Bulletin of China | Year: 2012

There are Mesozoic intrusive rocks along the Lancang River in Chala area of eastern Tibet, which mainly occur as complex batholiths and apophyses and lenticular granite that intruded in Early Carboniferous Kagongyanka Formation and Jitang Group metamorphic rocks. The intrusive rocks are mainly composed of monzonitic granite and granodiorite with a little diorite. So far, the genesis of these rocks, including their formation age and tectonic significance, has been poorly studied. In this paper, four granite samples were used for LA-ICP-MS U-Pb dating, and the dating results show that the age of a sample is 219.8 Ma ± 2.4 Ma, and the ages of the other three samples are 239.2 Ma ± 1.7 Ma, 241.5 Ma ± 2.3 Ma and 242.5 Ma ± 1.6 Ma respectively, suggesting similar formation ages in Middle-Late Triassic period. Geochemical studies indicate that these granites were formed in intraplate syncollisional to post-colli sional tectonic setting which underwent the evolution from early collision to the last stage of orogeny. The environment was a tectonic regime of the transformation stage regarded as a "post-orogenic" tectonic environment which was produced by crust anatectic melting as a result of crust extension and rapid uplift after the collision between the eastward Lancangjiang plate and the Changdu micro-plate.

Shi Z.-G.,Chinese Academy of Geological Sciences | Gao L.-Z.,Chinese Academy of Geological Sciences | Li T.-D.,Chinese Academy of Geological Sciences | Ding X.-Z.,Chinese Academy of Geological Sciences | And 4 more authors.
Geology in China | Year: 2014

The outcropped Neoproterozoic strata are relatively complete from old to young in Lushan area, and hence this area is significant for analyzing the tectonic evolution of the whole "Jiangnan Orogen". The Hanyangfeng Formation, which exists only in Hanyang peak of the Lushan Mountain, is mainly composed of terrestrial eruptional metacrystal or phenocryst-rare rhyolite. The authors obtained the high-precision SHRIMP zircon U-Pb weighted mean age(838±4 Ma, corresponding MSWD=1.12) of the metamorphic rhyolite of the Hanyangfeng Formation in the Lushan area, and also obtained LA-ICP-MS zircon U-Pb weighted mean age(852±4 Ma, corresponding MSWD=0.037) of this Formation. These new data indicate that the Hanyangfeng Formation does not belong to the Banxi period. The authors initially hold that the Hanyangfeng Formation ought to be located under the tectonic transformation of the Willing movement (820± Ma). The new research result confirms that the Hanyangfeng Formation is of the same volcanic-sedimentary strata as the Shaojiwa Formation, and therefore it may be a significant indicator to the tectonic setting. Actually, the sequence relationship of the Hangyangfeng Formation and the Shaojiwa Formation to the Xingzi Complex group shows upside-down phenomenon, suggesting that there probably existed a significant geological movement in the Lushan area during the late Qingbaikou period.

Wen B.-Y.,Jiangxi Institute of Geological Survey | Zhang T.-L.,Jiangxi Institute of Geological Survey | Li X.-Z.,Geophysical and Geochemical Exploration Party | Xie Z.-D.,Jiangxi Institute of Geological Survey
Geology in China | Year: 2014

The results of regional geochemical survey show that selenium content of topsoil is 0.34 mg/kg, which indicates that the soil in the study area is selenium-sufficient or selenium-rich. The results also show that the content of heavy metals in soil is at a safe level. Geochemical anomaly inspection reveals that the Se-rich bedrock controls the distribution of Se-rich soils. There are many kinds of selenium-rich and high-quality agricultural products in the study area, such as selenium-rich rice and soybean, with the proportion of the selenium-enriched soybean reaching 100%. There is a significant positive correlation between plant available selenium and total selenium, and a remarkable correlation between plant available selenium and soil CEC, N and P; the clay minerals and organic matters in soils have a strong adsorption and solidification function for selenium. The available selenium mainly exists in the form of selenite. The biological enrichment coefficients of selenium show a significant negative correlation with soil total selenium and nitrogen but a positive correlation with K2O.

Zhang J.,Jiangxi Institute of Geological Survey | Zhang F.-S.,Jiangxi Institute of Geological Survey | Yan J.-L.,Jiangxi Institute of Geological Survey | Ding S.-H.,Jiangxi Institute of Geological Survey | And 2 more authors.
Geological Bulletin of China | Year: 2014

The Nanling metallogenic belt, as an important natural heavy mineral anomaly belt of such resources as tungsten, tin, and rare earth elements, is located in the southwest of Jiangxi Province. The individual mineral anomalies in the belt, occurring in complicated shapes, are significantly controlled by natural geographical conditions and have close relationship with granitic intrusions as well as mineral deposits. The combination of anomalies trends in NNE direction and is accordant with structural lineation. According to the geological conditions and combined anomaly characteristics, the anomalies can be divided into two secondary natural heavy mineral anomaly belts and fourteen ore concentration areas. The natural heavy mineral anomalies in the study area fully demonstrate the potential of the mineral resources and can serve as important anomaly information indicators for the mineral resources investigation and appraisal. ©, 2014, China Geological Survey. All right reserved.

Gao L.-Z.,Chinese Academy of Geological Sciences | Liu Y.-X.,Chinese Academy of Geological Sciences | Ding X.-Z.,Chinese Academy of Geological Sciences | Song Z.-R.,Jiangxi Institute of Geological Survey | And 4 more authors.
Geological Bulletin of China | Year: 2013

This paper will report some SHRIMP U-Pb ages (1132 Ma±8 Ma, 1140 Ma±7 Ma, 1143 Ma±9 Ma and 1172 Ma±10 Ma) of meta-rhyolite of the Tieshajie Formation in the Jiao-Shao fault zone, which belongs to the Northern margin of Cathaysia. Combine of those dating, we will try to discuss the tectonic set of the Tianli schist, Zhoutan Complex and Wanyuan Complex. According to the isotopic dating, it is important for limit the strata correlation and tectonic evolution in the Jiao-Shao fault zone. The dating above mentioned shows the depositional strata of an ace-basin system in 1.1 Ga, which is represented inner ace between the Yangtze and Cathayasia and the Huaiyu area is an extensional basin of the back-are. The chronostratigraphic dating of the Tieshajie Formation proved the reliable isotopic evidence for the correlation of the metamorphosed strata in the Jiang-Shao fault zone.

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