Mei H.Q.,Geological Publishing House |
Jie W.Y.,China University of Geosciences
Proceedings of the 3rd Academic Conference of Geology Resource Management and Sustainable Development, GRMSD 2015 | Year: 2015
Xinglong National Geopark of Hebei Province, China (XLNG) has a great quantity of geoheritage with significance on scientific research and geotourism. The paper described geodiversity of XLNG, including the characteristics, scientific significance and formation processes, which embraces geological structures, ROCK MASSES AND DIFFERENT TYPES OF GEOMORPHOLOGIC LANDSCAPES AND SO ON.. WHAT'S MORE, GEOTOURISM BASED ON geoconservation in XLNG are studied, which may provide important information for geopark development in China. Source
Cao Y.,China University of Geosciences |
Zheng Z.,Geological Publishing House |
Du Y.,China University of Geosciences |
Gao F.,China University of Geosciences |
And 3 more authors.
Ore Geology Reviews | Year: 2016
The Hucunnan ore deposit is a representative skarn Cu-Mo deposit in the Tongling district, an important ore district of the renowned Middle-Lower Yangtze River metallogenic belt of China. The deposit shows distinct zonation of metals, with Cu mineralization distributed mainly in the exoskarn zone at shallow depths, and Mo mineralization occurring chiefly in the endoskarn zone located at deeper depths. Field evidence and petrographic observations indicate that the ore-forming processes can be divided into the skarn, quartz-molybdenite, quartz-chalcopyrite, and carbonate stages. Five types of fluid inclusions (FIs) are present in the deposit: solid-bearing (type 1), liquid-rich (type 2), vapor-rich (type 3), pure vapor (type 4), and CO2-bearing (type 5). The skarn stage contains mainly type 1 and 2, but also minor type 3 and 4 FIs; the FIs display homogenization temperatures of 434-570°C and salinities of 2.07-66.0wt.% NaCl equiv. The existence of hematite daughter minerals in the type 1 inclusions, together with the presence of magnetite in skarn, implies that the skarn-stage fluid was oxidizing. The skarnization of the granodiorite porphyry is commonly accompanied by potassic alteration, suggesting that the fluids were rich in alkali. Similar to the skarn stage, the quartz-molybdenite stage contains type 1 and 2, and minor type 3 and 4 FIs, which yield homogenization temperatures of 280-458°C and salinities of 1.40-54.2wt.% NaCl equiv. The presence of sulfide instead of hematite daughter minerals in the type 1 inclusions in quartz-molybdenite veins associated with sericitization indicates that the fluids of the quartz-molybdenite stage were more reducing and more acidic than the fluids in the skarn stage. The decrease in oxygen fugacity and increase in acidity could have resulted from magnetite crystallization and the consumption of alkali cations and OH-, respectively, during the skarn stage. The quartz-chalcopyrite stage contains all types of FIs, which show homogenization temperatures of 203-392°C and salinities of 1.22-46.6wt.% NaCl equiv. Observations of hematite-bearing type 1 FIs in quartz-chalcopyrite veins containing anhydrite associated with biotitization suggest that the fluids of the quartz-chalcopyrite stage were oxidizing and alkali-rich, probably on account of the inflow of meteoric water and boiling in an open system. In the carbonate stage, only type 2 FIs are present; these FIs yield the lowest homogenization temperatures of 156-276°C and the lowest salinities of 1.05-12.3wt.% NaCl equiv. Microthermometry and H-O isotope data indicate that the ore-forming fluids were dominated by magmatic water in the early stages (skarn and quartz-molybdenite stages), and that the magmatic water gradually mixed with circulating meteoric water during the late stages (quartz-chalcopyrite and carbonate stages). The coexistence of saline and vapor-rich FIs as internal trails or clusters within individual crystals, with similar homogenization temperatures but contrasting salinities and homogenization modes (to the liquid and vapor, respectively), in the first three stages strongly suggests that three episodes of fluid boiling occurred in these stages, as further supported by the hydrogen isotopic compositions of the fluids, which are lower than those of magmatic water. Based on the above data, we conclude that temporal changes in redox conditions, acidity, and temperature in the mineralizing fluids resulted in the temporal separation of Cu and Mo by selective sulfide precipitation in the Hucunnan skarn deposit. The competition among metals (e.g., Mo and Cu) for sulfur in magmatic fluids, along with vapor-brine immiscibility (fluid boiling), are major factors that contributed to the spatial separation of Cu and Mo in the deposit. © 2016 Elsevier B.V. Source
Liang Y.-P.,Geological Publishing House |
Zhang K.-X.,Hubei University |
Song B.-W.,Hubei University |
Wang G.-C.,Hubei University |
And 4 more authors.
Geological Bulletin of China | Year: 2013
Based on an integrated study of the geological maps and previous achievements, the authors analyzed the attributes, tectonic settings and lithofacies-stratigraphic sequences of the remnant basins in the Tibetan plateau. In Paleocene, the Tibetan Plateau was characterized by the erosional areas in western Kunlun, Altun, Qilian, western Qinling, Songpan-Garze and Gangdise, the Alxa and Indian ancient lands and the depressed basins (lakes and pluvial plains) in Xining-Lanzhou, Chengdu and Baingoin. There existed Neo-Tethyan remnant sea in western and southern Tibetan Plateau. It is held that the paleogeography of the Neo-Tethyan remnant sea was a remnant oceanic basin to the west of the Saga area and a foreland basin to the east of Saga during the Paleocene. The authors argue that the closure of the Neo-Tethys progressed from east to west. Source
Li C.-L.,Heilongjiang Institute of Geological Survey |
Li C.-L.,China University of Geosciences |
Li S.-R.,China University of Geosciences |
Luo J.-Y.,Geological Publishing House |
And 2 more authors.
Geology in China | Year: 2011
The Yixingzhai gold deposit is located in Fansi County, Shanxi Province, whose mineralization belongs to quartz-vein type. The main gold mineral is single electrum, together with minor native gold. The gold minerals commonly assume rounded, wheat-like , irregular brecciated and veinlet forms, with grain size in the range of 10-50 μm in diameter. They occur mainly in gold-bearing minerals such as pyrite, chalcopyrite and quartz, in the form of inclusion gold, intercrystalline gold and fissure gold. The authors made statistical analysis of the shapes, grain sizes and modes of occurrence of gold minerals by using quantity statistical method and area statistical method, and the results indicate that different gold minerals show remarkable differences in occurrence rate and area distribution. Gold-bearing minerals generally contain iron, sulfur, copper, zinc and lead. Analytical results indicate that iron and sulfur show inverse correlation with gold, and have stable lead content and remarkably varying copper and zinc content. In combination with the relationship between the temperature and the Au and Ag content, the authors suggest that the gold minerals formed in medium-low temperature. The average gold fineness ranges from 510.7 to 887.9 with an average of 653.6, suggesting an epithermal metallogenic environment for the Yixingzhai gold deposit. From 1350 m level to 1070 m level, the average fineness of gold minerals gradually decreases from 778.4 to 651.7, showing characteristics of reverse zoning and indicating that there probably exist stable ore bodies below 1070 m level. Source
Li S.,China University of Geosciences |
Gao Y.,Makah Fisheries Management |
Luo J.,Geological Publishing House |
Cao Y.,China University of Geosciences |
And 5 more authors.
African Journal of Biotechnology | Year: 2011
This paper reports a pilot study on the thermoluminescence (TL) of carbonate minerals of carp otoliths from the heavily polluted Baiyangdian Lake (BYD) in Hebei Province and non-polluted Miyun Water Reservoir (MY) in Beijing Municipality of China. Analyses on trace elements of otoliths and water show that the heavy metal elements of BYD were much higher than those of MY, particularly on chromium (Cr), nickel (Ni), zinc (Zn) and rubidium (Rb) concentrations. These heavy metal elements could infiltrate into the otolith crystals as impurities or defeats, and were responsible for the different TL parameters and TL glow curves between BYD and MY samples. Such differences in carp otoliths would be applicable to other lakes or water reservoirs, and the TL technique could be used as fingerprint in identification of polluted and non-polluted lakes. Also, the TL characteristics of fish otoliths may provide a quick and qualitative means for environmental assessments in lake pollution. © 2011 Academic Journals. Source