Origin and geodynamic significance of fault-hosted massive sulfide gold deposits from the Guocheng-Liaoshang metallogenic belt, eastern Jiaodong Peninsula: Rb-Sr dating, and H-O-S-Pb isotopic constraints
Tan J.,Wuhan University |
Wei J.,Wuhan University |
Li Y.,Wuhan University |
Fu L.,Wuhan University |
And 3 more authors.
Ore Geology Reviews | Year: 2015
More recent explorations (from 2009 to 2013) indicate a minimum of 27tonnes Au of additional resources in the Guocheng-Liaoshang gold belt, northeastern Jiaolai basin, Jiaodong gold province. The ores are hosted in faults/fractures in Paleoproterozoic metamorphic and granitic rocks, and are marked by massive sulfide type with sulfides of up to 40 to 95vol.%. Rb-Sr isotopic dating of mineralized quartz yielded an isochron age of 116.2±2.4Ma (MSWD=0.36). The ore-related quartz samples have δD values of -86 to -69‰ (mean -78‰), with calculated δ18OH2O values of 0.6 to 7.7‰ (average 3.6‰). The δ34S values of ore sulfides vary from 8.5 to 12.7‰ with an average of 9.9‰. Lead isotope signatures recorded in sulfides are much less radiogenic (206Pb/204Pb=17.039-17.862) relative to that of Phanerozoic convecting mantle (206Pb/204Pb=18.179-18.384). These results show that the gold mineralization style in this belt is different from the traditionally identified three types of gold deposits in the Jiaodong Peninsula (namely, Linglong, Jiaojia and Pengjiakuang type). They also suggest deep-seated, most likely mafic dike magmatic and mantle-derived, sources for the ore fluids, sulfur and metals in the hydrothermal system, despite the fact that wall rocks might provide some sulfur to satisfy the enriched 34S signature. The inferred mantle reservoir was probably formed by subduction-related fluid metasomatism during the Paleoproterozoic (ca. 1.85Ga) Jiao-Liao-Ji mobile belt assembly (suture within Columbia supercontinent). Extensional tectonic inversion during early Cretaceous, caused by subduction of the Kula-Pacific plate rather than postcollisional process of the Qinling-Dabie-Sulu Orogen, triggered partial melting of this mantle domain, subsequent magma mixing and final exsolution of ore-forming fluids. © 2014 Elsevier B.V. Source
You Y.,Huazhong University of Science and Technology |
You Y.,Wuhan University |
Zhou M.,Wuhan University |
Hou H.,Wuhan University |
And 2 more authors.
2011 2nd International Conference on Mechanic Automation and Control Engineering, MACE 2011 - Proceedings | Year: 2011
The instability of the sludge will cause odor and other environmental pollution in the process of disposal and reuse. HAS soil stabilizer, Lime and Portland cement are used in this paper to modify the sewage. The experimental results showed that added by a certain content of the HAS Soil Stabilizer in sludge would be a good modification effect on removing Ammonia and Hydrogen Sulfide. When the curing time was 14d and the content was 15%, the concentration of Ammonia was 5μg/L and the removal rate could reach 93.5%. When the curing time was 3d and the content was10% or more, the concentration of Hydrogen Sulfide can be reduced to below 0.06μg/L and the removal rate could reach 95%, conforming to the relative standards. The SEM photos of 15% HAS modified sludge showed that Ettringite and Calcium Silicate hydrate crystals were the mainly hydration products, they formed a kind of three-dimensional crystal network and completely changed the original sludge structure, which effectively prevented the organic matter to further decay, made the sludge stabilized and achieved the improvement of sludge odor. © 2011 IEEE. Source
Li K.,Hubei University |
Wu C.-X.,Hubei Institute of Geological Survey
Geology in China | Year: 2014
Great progress has been made in recent years in prospecting for Pb- Zn ore deposits in western Hunan and eastern Guizhou provinces. There are more than two hundred Pb-Zn ore deposits hosted in the Cambrian and Ordovician strata. The authors carried out a systematic analysis of the carbon and oxygen isotopic compositions of carbonate wall rocks and hydrothermal calcites formed at the ore-forming stage. The results show that carbonate wall rocks have relatively homogeneous δ 13CPDb values (ranging from-1.16‰ to 1.70‰, 0.51‰ on average) and δ 18OSMow values (ranging from 18.56‰ to 22.42‰, 21.04‰ on average); in contrast, hydrothermal calcite has lower δ 13CPDb value (ranging from-5.80‰ to 0.42‰, -1.18‰ on average), and significantly declined δ 18OSMow values (ranging from 12.96‰ to 23.05‰, 18.36‰ on average). In the δ 13Cpdb VS δ 18Osmow diagram, the wall rocks are plotted in the marine carbonate rock area, and hydrothermal calcites are between marine carbonate rock and upper mantle. In combination with previous results, it is concluded that C of the ore-forming fluids was mainly derived from carbonate wall rocks, sulfur from sulfates in the sedimentary strata, and Pb and Zn from the rocks of lower Cambrian Niutitang Formation. The ore-forming fluids were higher salinity and lower temperature basin brines. Precipitation of ore minerals and hydrothermal calcites probably resulted from extensive fluid-rock interaction between ore-forming fluids and carbonate wall rocks in combination with corresponding decreasing temperature. Source
Xi X.,China Geological Survey |
Li M.,China Geological Survey |
Zhang X.,Hebei Institute of Geological Survey |
Zhang Y.,Henan Institute of Geological Survey |
And 4 more authors.
Earth Science Frontiers | Year: 2013
Soil organic carbon in middle-east China can be studied by comparison based on the data obtained by multi-purpose regional geochemical survey. The middle-east plain covers the terrain of Hebei, Henan, Hubei, Hunan, Guangdong and Hainan provinces, ranging from relatively higher latitude to low latitude and crossing temperate zone, subtropical zone and tropical zone. More than 334000 km2 were covered in the multi-purpose regional geochemical survey. Top soil (0-0.2 m) carbon storage is 906.84 Mt and average carbon density is 2716.93 t/km2. Including the higher soil carbon density in the northeastern plain, the carbon density in middle-east regions of China exhibited the changing pattern of high low high low from the northeastern plain downward to Hainan Province, that is 3327.8 t/km2 (northeastern plain)→2207.39, 2421.02 t/km2 (Hebei and Henan)→3442.15, 3942.92 t/km2 (Hubei and Hunan)→2255.90, 2936.72 t/km2(Guangdong and Hainan). The soil carbon density in agricultural ecosystem and urban ecosystem presented different changing rule from higher latitude to lower latitude, i.e., in agricultural farmland it changes from low to high, and in urban soil from high to low. The soil organic carbon increased by 14.5% (totally increasing 115.18 Mt and annually averaging 5.76 Mt/a) during past 20 years compared to the value achieved by the second soil reconnaissance. However organic carbon did not increase evenly. The rising rate decreased from low latitude to high latitude, and organic carbon increased in agricultural and urban ecosystem but decreased in tideland, rivers, lakes, grassland, forest and swamp. Source
Zhang S.,CAS Guangzhou Institute of Geochemistry |
Zhang S.,Wuhan University |
Yang D.,China Southwest Geotechnical Investigation and Surveying Institute |
Li F.,Wuhan University |
And 5 more authors.
Applied Geochemistry | Year: 2014
The soil geochemical baseline is an important index in environmental assessment. Detailed baseline studies are necessary in large areas with complex geological settings, landforms and soil types. The Jianghan plain, a major industrial and agricultural region located in central China, has a soil geochemical baseline that has yet to be fully defined. The objective of this paper is to study the baseline of Cd, Pb and Zn in the topsoil of the Jianghan plain in a subarea using principal component regression (PCR). A total of 9030 samples were collected from the surface layer, and 2 soil profiles and 2 sedimentary columns were sampled near the Yangtze and Han rivers. Fifty-two elements and two parameters were analyzed. Data processing and the creation of spatial distribution maps of the elements were performed using MapGIS, R and SPSS software. The results show that the distributions of Cd, Pb and Zn are mainly controlled by parent material, drainage system and soil type. The study area is divided into 3 subareas, with factors reflecting the physico-chemical characteristics of the soil using factor analysis (FA). The geochemical baseline model is established in every subarea to predict the Cd, Pb and Zn values using principal component regression analysis (PCR); the exceptional values (as a result of anthropogenic input or mineralization) are distinguished by residuals (γ); and the natural background values and anthropogenic contributions are clearly distinguished. Therefore, the PCR method in these subareas is objective and reasonable, and the conclusion provides effective evidence of exceptional high values for further environmental assessment. © 2014. Source