10 results on '"Li Yanhe"'
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2. In situ LA–MC–ICP–MS boron isotope and zircon U–Pb age determinations of Paleoproterozoic borate deposits in Liaoning Province, northeastern China
- Author
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Fan Changfu, Yue Zhao, Kejun Hou, Lingsen Zeng, Guyue Hu, and Li Yanhe
- Subjects
Basalt ,geography ,Olivine ,geography.geographical_feature_category ,Tourmaline ,Evaporite ,Geochemistry ,Mineralogy ,Geology ,engineering.material ,Troilite ,Volcanic rock ,Geochemistry and Petrology ,Ultramafic rock ,engineering ,Economic Geology ,Zircon - Abstract
A large number of Paleoproterozoic borate deposits are hosted by the lower units of a volcanic-sedimentary sequence in Liaoning Province, northeastern China, and are a major source of boron in China. The ore-bearing wall rocks in the deposits are serpentinized ultrabasic rocks and carbonates, with layered leptynites, leptites, amphibolites, and migmatites adjacent to the ore. Both the borate ores and country rocks contain tourmaline, although the country rocks have much lower abundances of the mineral. Based on in situ boron isotope measurements using laser ablation–multi-collector–inductively coupled plasma–mass spectrometry (LA–MC–ICP–MS), boron isotope data show that: (1) δ 11 B values of borate ores range from + 6.8‰ to + 13.9‰ (mean + 10.8‰); (2) tourmalines from the borate ores have δ 11 B values from + 9.5‰ to + 12.7‰; and (3) the wall rocks within the borate ores yield slightly lower δ 11 B values ranging from + 5.7‰ to + 7.6‰, and those outside the deposits from − 9.9‰ to − 5.9‰. Positive δ 11 B values in borates as well as in tourmalines inside the mining area indicate that boron in these Paleoproterozoic borate deposits was derived from marine evaporites. δ 34 S V-CDT (where V-CDT is Vienna Canyon Diablo Troilite) values of borate ores, serpentinized marbles, and anhydrites range from + 16.1‰ to + 24.7‰, whereas δ 13 C V-PDB (where V-PDB is Vienna Pee Dee Belemnite) values of marbles range from + 3.2‰ to + 5.9‰. These isotopic characteristics are interpreted to reflect formation in a marine evaporative environment. LA–MC–ICP–MS zircon weighted 207 Pb/ 206 Pb ages of leptite and serpentinized olivine basalt from the hanging wall of the borate deposits are 2139 ± 13 Ma and 2130 ± 19 Ma, respectively. Therefore, the (~ 2.2 Ga) borate deposits may have originated from marine evaporative boron-bearing sediments, which were interbedded within bimodal volcanic rocks during the early stages of development of the Liaoji rift.
- Published
- 2015
3. Separation and Precise Measurement of Lithium Isotopes in Three Reference Materials Using Multi Collector-Inductively Coupled Plasma Mass Spectrometry
- Author
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Hou Kejun, Yang Zhusen, Hou Zengqian, Zhao Yue, Gao Yan-guang, Yang Dan, SU Aina, Tian Shihong, LI Zhenzhen, LI Yanhe, and HU Wenjie
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education.field_of_study ,Magnesium ,Isotopes of lithium ,Population ,Analytical chemistry ,chemistry.chemical_element ,Mineralogy ,Geology ,Standard solution ,Mass spectrometry ,chemistry ,Reagent ,Lithium ,education ,Inductively coupled plasma mass spectrometry - Abstract
Lithium separation technique for three reference materials has been established together with precise determination of lithium isotope using a Neptune multi collector-inductively coupled plasma mass spectrometry (MC-ICP-MS). The solutions of lithium element standard reference materials, potassium, calcium, sodium, magnesium and iron single element, were used to evaluate analytical methods applied. Three separate stages of ion-exchange chromatography were carried out using organic cation-exchange resin (AG 50W-X8). Lithium was enriched for the three stages using different eluants, which are 2.8 M HCl, 0.15 M HCl and 0.5 M HCl in 30% ethanol, respectively. The columns for the first and second stages are made of polypropylene, and those for the third stage are made of quartz. Total reagent volume for the entire chemical process was 35 mL for three reference materials. The recovery yielded for the three stages is 98.9-101.2% with an average of 100.0%, 97.6-101.9% with an average of 99.9%, and 99.8-103.3% with an average of 100.6%, respectively. The precision of this technique is conservatively estimated to be ±0.72-1.04‰ (2σ population), which is similar to the precision obtained by different authors in different laboratories with MC-ICP-MS. The δ7 Li values ( 7 Li/ 6 Li relative to the IRMM-016 standard) determined for andesite (AGV-2) and basalt (BHVO-2) are 5.68‰ (n=18), 4.33‰ (n=18), respectively. The δ7 Li value ( 7Li/6Li relative to the L-SVEC standard) determined for IRMM-016 is -0.01‰ (n=15). All these analytical results are in good agreement with those previously reported. In addition, the results for the same kinds of samples analyzed at the MLR Key Laboratory of Metallogeny and Mineral Assessment, Institute of Mineral Resources, Chinese Academy of Geological Sciences, are consistent with those obtained at the Plasma Laboratory, University of Maryland, within analytical uncertainty. According to these experiment results, it is concluded that this proposed procedure is a suitable method for determining the lithium isotopic composition of natural samples.
- Published
- 2012
4. Discovery of Mass Independent Oxygen Isotopic Compositions in Superscale Nitrate Mineral Deposits from Turpan-Hami Basin, Xinjiang, China and Its Significance
- Author
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Qin Yan, Liu Feng, Wan Defang, LI Yanhe, and Hou Kejun
- Subjects
Mineral ,δ18O ,Mineralogy ,chemistry.chemical_element ,Geology ,Fractionation ,Oxygen ,Isotopes of oxygen ,Troposphere ,chemistry.chemical_compound ,Nitrate ,chemistry ,Environmental chemistry ,Stratosphere - Abstract
The Turpan-Hami Basin in eastern Xinjiang is one of the driest regions on Earth and a premier environment to form and preserve nitrate. A large nitrate ore field in this basin was found recently. It is estimated there are about 2.5 billion tons of resources of nitrate, and the amount is as much as the Atacama Desert super-scale nitrate deposit in Chile. Nitrate is one of a few minerals with mass-independent fractionation (MIF), and the oxygen isotope MIF is an effective method to determine the source of nitrate. The δ17O, δ18O of nitrate were measured by fluorination and thermal decomposition method. The date indicated that this is the first time that oxygen isotope MIF has been located in inland nitrate minerals. The results obtained by two methods are similar, Δ17O=δ17O–0.52×δ18O=12‰–17‰. The experiment and observation data proved that oxygen isotope MIF of nitrate are the result of photochemical reactions in the troposphere and stratosphere. Thus, evidence from MIF oxygen isotopic compositions indicate that long term atmospheric deposition of nitrate aerosol particles produced by photochemical reactions is the source of the deposits.
- Published
- 2010
5. Extreme Enrichment of Tellurium in Deep-Sea Sediments
- Author
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Song Hebin, Yue Guoliang, Wang Yimin, and LI Yanhe
- Subjects
Interplanetary dust cloud ,chemistry ,Abundance (ecology) ,chemistry.chemical_element ,Mineralogy ,Geology ,Crust ,Tellurium ,Isotopes of helium ,Deep sea ,Earth (classical element) ,Helium - Abstract
Tellurium is a sort of scattered rare element on the earth. Its concentration is very low in earth’s crust, only 1.0 ng/g. However, it has extremely high abundance in Co-rich crusts, marine polymetallic nodules, deep-sea sediments and aerolites. To find out the origin of tellurium enrichment in deep-sea sediments, we analyzed and compared tellurium concentrations and helium isotope compositions in the magnetic parts and those in the bulk parts of deep-sea sediments. The result indicates that the helium content, 3He/4He ratio and tellurium concentration are obviously higher in the magnetic parts than those in the bulk parts. The 3He abundance varies synchronously with the tellurium concentration. 3He and Te have a distinct positive correlation with each other. It is the first time that the paper brings forward that the extreme enrichment of tellurium in deep-sea sediments, like helium isotope anomalies, probably results from the input of interplanetary dust particles (IDPs). Similarly, the extreme enrichment of tellurium in marine polymetallic nodules and Co-rich crusts is possibly related to IDPs.
- Published
- 2005
6. Relationship between polymetallic nodules and submarine hydrothermalism in the Central Pacific Ocean
- Author
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LI Yanhe, Song Hebin, LI Jincheng, and Yao Xiaomei
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Multidisciplinary ,chemistry ,Geochemistry ,Mineralogy ,chemistry.chemical_element ,Pyroclastic rock ,Submarine ,Manganese ,Ferromanganese ,Pacific ocean ,Geology ,Hydrothermal circulation - Abstract
THE huge reserves of submarine polymetallic nodules make them an important kind of potentialmineral resources. It has already been discovered that polymetallic nodules are related withsubmarine vollcanogene hydrothermalism. For example, pyroclasts usually occur as coresubstances of the nodules, and large amounts of mineralizing materials such as manganese aredischarged to form ferromanganese oxides along with the submarine vocanogene hydrothermal-...
- Published
- 1997
7. Ba-rich micas from the Yindongzi-Daxigou Pb-Zn-Ag and Fe deposits, Qinling, northwestern China
- Author
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M. R. Palmer, Li Yanhe, Xue Chunji, and Shao-Yong Jiang
- Subjects
Baryte ,010504 meteorology & atmospheric sciences ,Muscovite ,Geochemistry ,Mineralogy ,Metamorphism ,engineering.material ,010502 geochemistry & geophysics ,Feldspar ,01 natural sciences ,Diagenesis ,Geochemistry and Petrology ,visual_art ,engineering ,visual_art.visual_art_medium ,Sedimentary rock ,Clay minerals ,Biotite ,Geology ,0105 earth and related environmental sciences - Abstract
Electron-microprobe analyses of muscovite, biotite, and feldspar are reported for the stratiform Yindongzi—Daxigou Pb—Zn—Ag and Fe deposits of Qinling, northwestern China. The micas are characterized by high Ba levels in banded albite-carbonate rocks that host the deposits. The biotite is also rich in Cl, as is biotite in the nearby Tongmugou Pb-Zn deposit, although biotite and muscovite from this deposit lack Ba enrichment. It is likely that the Ba-rich micas in the Yindongzi-Daxigou deposits formed contemporaneously from the diagenesis and/or regional metamorphism of hydrothermally altered clay minerals, with the barium being derived from entrained pore fluids that may represent relict hydrothermal fluids associated with ore deposition. During the formation of coexisting muscovite and biotite, barium is preferentially partitioned into muscovite and chloride into biotite. Together with the presence of baryte rocks in the bedded ores, these data suggest that ore deposition in the Yindongzi—Daxigou deposits took place in a more oxidising environment than in the nearby Tongmugou deposit. This difference is attributed to the contrasting sedimentary environments of the two deposits, with the Yindongzi—Daxigou deposits having formed under shallow, oxic conditions and the Tongmugou deposit under deeper, anoxic conditions.
- Published
- 1996
8. Experimental study of silicon isotope dynamic fractionation and its application in geology
- Author
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LI Yanhe, Wan Defang, and Ding Tiping
- Subjects
Isotope ,Silicon ,Geochemistry ,chemistry.chemical_element ,Mineralogy ,Fractionation ,Mass-independent fractionation ,Equilibrium fractionation ,chemistry.chemical_compound ,chemistry ,Geochemistry and Petrology ,Carbonate ,Isotopes of silicon ,Clay minerals ,Geology - Abstract
Silicon shows no variation in its chemical valence in nature and exists mainly in the form of silicon-oxygen tetrahedra, so very small silicon isotope thermodynamic fractionation occurs and the resultant silicon isotope variation is limited. Dynamic fractionation of Si isotopes during precipitation of SiO2 from a solution is a main factor leading to substantial variations in silicon isotopes in nature. In this experimental study, we determined the dynamic fractionation factorα for silicon isotopes during precipitation of SiO2 from the solution. And in combination of α, a theoretical explanation is presented of the considerably low δ30Si values of black smokers on modern seafloor, Archean banded magnetite-quartzite and clay minerals of weathering origin, and of clearly high δ30Si values of siliceous rocks in shallow-sea carbonate platforms.
- Published
- 1995
9. Mineralogical and sulfur isotopic evidence for the incursion of evaporites in the Jinshandian skarn Fe deposit, Edong district, Eastern China.
- Author
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Zhu, Qiaoqiao, Xie, Guiqing, Mao, Jingwen, Li, Wei, Li, Yanhe, Wang, Jian, and Zhang, Ping
- Subjects
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MINERALOGY , *SULFUR isotopes , *EVAPORITES , *ORE deposits , *COMPARATIVE studies - Abstract
Evaporites have played important role in the formation of diverse metallic ore deposits, especially in the case of magmatic–hydrothermal deposits. However, the relationship between evaporites and skarn Fe deposit remains poorly constrained. In this contribution, we present new sulfur isotope data of pyrite, as well as the composition of halogen-rich minerals (scapolite and amphibole) in the Jinshandian skarn Fe deposit. The data are used to evaluate the evidence for incursion of evaporites in the skarn Fe deposit. The δ 34 S values for pyrite from the early and late retrograde stage range from +17.4‰ to +18.7‰ ( n = 4) and +16.4‰ to +19.4‰ ( n = 13), respectively. Both these values are markedly heavier than the common δ 34 S values of sulfides from magmatic–hydrothermal fluid, indicating that sulfur in the Jinshandian ore-forming system was mostly derived from evaporites. Compared to the amphibole from endoskarn, the scapolite and amphibole from exoskarn show high Cl content up to 4.04% and 3.01%, respectively, suggesting that the hydrothermal fluid with high NaCl content was probably derived from evaporites. The amphiboles from endoskarn are more enriched in F which is probably of magmatic in origin. The data presented in our study suggest that the hydrothermal system of the Jinshandian skarn Fe deposit probably experienced significant incursion of evaporites before or during the late prograde stage. [ABSTRACT FROM AUTHOR]
- Published
- 2015
- Full Text
- View/download PDF
10. Geochemical constraints on Cu–Fe and Fe skarn deposits in the Edong district, Middle–Lower Yangtze River metallogenic belt, China.
- Author
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Xie, Guiqing, Mao, Jingwen, Zhu, Qiaoqiao, Yao, Lei, Li, Yanhe, Li, Wei, and Zhao, Haijie
- Subjects
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GEOCHEMISTRY , *COPPER ores , *HYDROTHERMAL deposits , *SKARN , *SULFUR isotopes , *METALLOGENIC provinces , *MINERALOGY - Abstract
Copper and iron skarn deposits are economically important types of skarn deposits throughout the world, especially in China, but the differences between Cu and Fe skarn deposits are poorly constrained. The Edong ore district in southeastern Hubei Province, Middle–Lower Yangtze River metallogenic belt, China, contains numerous Fe and Cu–Fe skarn deposits. In this contribution, variations in skarn mineralogy, mineralization-related intrusions and sulfur isotope values between these Cu–Fe and Fe skarn deposits are discussed. The garnets and pyroxenes of the Cu–Fe and Fe skarn deposits in the Edong ore district share similar compositions, i.e., dominantly andradite (Ad 29–100 Gr 0–68 ) and diopside (Di 54–100 Hd 0–38 ), respectively. This feature indicates that the mineral compositions of skarn silicate mineral assemblages were not the critical controlling factors for variations between the Cu–Fe and Fe skarn deposits. Intrusions associated with skarn Fe deposits in the Edong ore district differ from those Cu–Fe skarn deposits in petrology, geochemistry and Sr–Nd isotope. Intrusions associated with Fe deposits have large variations in their (La/Yb) N ratios (3.84–24.6) and Eu anomalies (δEu = 0.32–1.65), and have relatively low Sr/Y ratios (4.2–44.0) and high Yb contents (1.20–11.8 ppm), as well as radiogenic Sr–Nd isotopes (εNd(t) = − 12.5 to − 9.2) and ( 87 Sr/ 86 Sr) i = 0.7067 to 0.7086. In contrast, intrusions associated with Cu–Fe deposits are characterized by relatively high Sr/Y (35.0–81.3) and (La/Yb) N (15.0–31.6) ratios, low Yb contents (1.00–1.62 ppm) without obvious Eu anomalies (δEu = 0.67–0.97), as well as ( 87 Sr/ 86 Sr) i = 0.7055 to 0.7068 and εNd(t) = − 7.9 to − 3.4. Geochemical evidence indicates a greater contribution from the crust in intrusions associated with Fe skarn deposits than in intrusions associated with Cu–Fe skarn deposits. In the Edong ore district, the sulfides and sulfates in the Cu–Fe skarn deposits have sulfur isotope signatures that differ from those of Fe skarn deposits. The Cu–Fe skarn deposits have a narrow range of δ 34 S values from − 6.2‰ to + 8.7‰ in sulfides, and + 13.2‰ to + 15.2‰ in anhydrite, while the Fe skarn deposits have a wide range of δ 34 S values from + 10.3‰ to + 20.0‰ in pyrite and + 18.9‰ to + 30.8‰ in anhydrite. Sulfur isotope data for anhydrite and sedimentary country rocks suggest that the formation of skarns in the Edong district involved the interaction between magmatic fluids and variable amounts of evaporites in host rocks. [ABSTRACT FROM AUTHOR]
- Published
- 2015
- Full Text
- View/download PDF
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