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| 1 | Paleoceangraphic significance of redox-sensitive metals of black shales in the basal Lower Cambrian Niutitang Formation in Guizhou Province, South China显示文摘Black shales of the Lower Cambrian Niutitang Formation occur widely on the Yangtze Platform. In this study, we analyzed black shales from two sections (Zhongnan and Zhijin) in Guizhou Province. The redox-sensitive metal concentration and distribution of black shales from the two sections provide good evidence for the anoxic conditions of the basal Cambrian ocean on the Yangtze Platform. Our geochemical data suggest that the black shales from the Zhongnan section may have deposited in a more strongly anoxic environment than the black shales in the Zhijin section. | YANGJinghong JIANGShaoyong LINGHongfei FENGHongzhen CHENYongquan CHENJianhua | 2004 | Progress in Natural Science:Materials International2004，14，2： | 26 |
| 2 | Metallogenetic Mechanism and Timing of Late Superimposing Fluid Mineralization in the Dongguashan Diplogenetic Stratified Copper Deposit,Anhui Province显示文摘An important diplogenetic mineralization event superimposed on pre-existing exhalation sediments in the Tongling area, Anhui province, was triggered by widespread granitic magmatism along the northeastern margin of the Yangtze Block during 140–135 Ma under extensional tectonic circumstances following the collision between the North China and Yangtze blocks. The main orebodies of the Dongguashan copper deposit, a typical diplogenetic stratified deposit among many polymetallic ore deposits in China, are hosted by strata between Upper Devonian sandstone and Carboniferous limestone, and its mineralization was genetically related to the Qingshanjiao intrusive. The Rb-Sr isotopic isochron of the Qingshanjiao intrusive yields an age of about 136.5±1.4 Ma. The ore-forming fluid reflected by the inclusion fluid in quartz veins is characterized by high temperature and high salinity, and its age was also determined by Rb -Sr isotope dating as 134±11 Ma. Oxygen and hydrogen isotope composition data suggest that the ore-forming fluid was derived mainly from magmatism. By integrating these isotopic dating data, characteristics of fluid inclusions and the geology of the deposit, the mineralization of the Dongguashan copper deposit is divided into two stages. First, a stratiform sedimentary deposit or protore layer formed in the Late Devonian to the Early Carboniferous, while in the second stage the pre-existing protore was superimposed by hydrothermal fluid that was derived from the Yanshanian magmatic activities occurring around 135 Ma ago. This two-stage mineralization formed the Dongguashan statiform copper deposit. Associated “porphyry” mineralization found in the bottom of and in surrounding intrusive rocks of the orebodies might have occurred in the same period as a second-stage mineralization of this deposit. | XUZhaowen LUXiancai LINGHongfei LUJianjun JIANGShoyong NIEGuiping HUANGShunsheng HUAMing | 2005 | Acta Geologica Sinica(English Edition)2005，79，3： | 21 |
| 3 | δ^(13)C_(carb) and Ce_(anom) excursions in the post-glacial Neoproterozoic and Early Cambrian interval in Guizhou, South China显示文摘Secular δ 13 C carb and Ce anom profiles in the post-glacial Neoproterozoic and Early Cambrian interval are reported from Guizhou on the southeasten border of the Yangtze platform, South China. Overall, the δ 13 C carb profile drifts to negative values in the post-glacial Nantuo and lower to middle Doushantuo Formations, and then to positive values in the upper Doushantuo and Dengying Formations of Neoproterozoic, followed by negative values in the Lower Cambrian Gezhongwu and Niutitang Formations. A detailed investigation of the relationship between the δ 13 C carb and Ce anom profiles reveals that the main anoxic and oxic episodes are coupled with negative and positive δ 13 C carb values, respectively. This may suggest a control of alternation between ocean stratification and mixing on variations in 13 C abundance in the ancient ocean of the investigated areas. | FENGHongzhen LINGHongfei JIANGShaoyong YANGJinghong | 2004 | Progress in Natural Science:Materials International2004，14，2： | 10 |
| 4 | Variation of the Fe/Mn ratio of ferromanganese crusts from the Central North Pacific: implication for paleoclimate changes显示文摘Contents of Fe, Mn and other elements in four ferromanganese crusts recovered from the central North Pacific are analyzed at high depth-resolution by electron microprobe for reconstructing factors controlling their deposition. Manganese (IV) in hydrogenetic ferromanganese crusts is mainly supplied as colloidal precipitates from the Oxygen Minimum Zone (OMZ), which concentrates high amounts of dissolved Mn (II). The iron is derived from carbonate dissolution and silicate particles of eolian dust. An increase in paleoproductivity during cooler climate would potentially lead to a decrease in Mn deposition due to enlargement of the OMZ which has a “temporary storage” effect for Mn. On the other hand, not affected by the OMZ, the iron entering the Fe-Mn crust would likely increase with the eolian dust input and surface productivity at glacial stages. As a result, the increasing Fe/Mn ratio should indicate a cooling climate. This is supported by the following observations. In the profile of the past 1 Ma, the variations of Fe/Mn ratio coincide with benthic oxygen isotope fluctuation in glacial-interglacial cycles. Three episodes with high Fe/Mn ratios, approximately at 2.6, 1.8 and 0.8 Ma, are detected within the past 3 Ma and coincide with major climate transitions and cooling events. The secular evolution pattern of Fe/Mn ratio in the Cenozoic is similar to the Pb isotope evolution which is mainly controlled by eolian dust and related to climate. The Fe/Mn evolution pattern is also broadly consistent with the global deep-sea oxygen isotope records. Therefore, Fe/Mn ratio recorded in the ferromanganese crusts may be a new proxy for climate change. | LUZunli LINGHongfei ZHOUFeng JIANGShaoyong CHENXiaoming ZHOUHuaiyang | 2005 | Progress in Natural Science:Materials International2005，15，6： | 9 |
| 5 | Oxygen isotope geochemistry of phosphorite and dolomite and palaeo-ocean temperature estimation:A case study from the Neoproterozoic Doushantuo Formation, Guizhou Province, South China显示文摘The Neoproterozoic Doushantuo Formation at Weng’an in Guizhou Province of South China consists of phosphorites and dolomites. Three types of samples are recongnized for the phosphate bearing rocks. In Type I samples, interstitial phosphates occur within the dolomite rocks, whereas in Type III samples, interstitial dolomites occur within the phosphorites; both of them may have diagenetic origin. The Type II samples are interbedded phosphorites and dolomites. Oxygen isotopic compositions of phosphate and coeval carbonate were analyzed. Phosphates of Type I and II samples show similar low δ 18 O phos (SMOW) values of 10.9‰~12.1‰ and 10.7‰~ 12.8‰ , respectively, whereas Type III phosphates show higher δ 18 O phos (SMOW) values of 13.2‰~15.0‰. Dolomites from Type I and II samples have δ 18 O carb (PDB) and δ 13 C carb (PDB) values of -6.2‰~-3.4‰ and -2.2‰~-0.7‰, respectively, whereas interstitial dolomites from Type III samples show lower δ 18 O carb (PDB) and δ 13 C carb (PDB) values of -12.9‰~-8.6‰ and -4.4‰~-2.6‰. Petrology and oxygen isotope data suggest that diagenetic alteration may have partially affected the studied rocks, but the dolomites from Type I and phosphates from Type III samples represent the most pristine isotopic compositions of primary carbonates and phosphates precipitated from seawater. Calculations of palaeocean temperatures from the most 18 O enriched dolomite and phosphate indicate a temperature range of 32.2 ℃ to 34.0 ℃ for the seawater of the Doushantuo Formation period. Ce anomaly also suggests more oxic conditions and possibly shallower water depth in the upper strata of the Doushantuo Formation at Weng’an, Guizhou Province. | LINGHongfei JIANGShaoyong FENGHongzhen CHENYongquan CHENJianhua YANGJinghong | 2004 | Progress in Natural Science:Materials International2004，14，1： | 9 |
| 6 | Metallogenetic Mechanism and Timing of Late Superimposing Fluid Mineralization in the Dongguashan Diplogenetic Stratified Copper Deposit, Anhui Province显示文摘 | XUZhaowen LUXiancai LINGHongfei LUJianjun JIANGShoyong NIEGuiping HUANGShunsheng HUAMing | 2010 | Acta Geologica Sinica ‐ English Edition2010，，3： | 1 |
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