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Hydrochemical Characteristics and Evolution of Underground Brine in Lop Nur,Northwestern China

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Acta Geologica Sinica(English Edition) 2024年第3期98卷 786-800页

作者： BO Ying LIU Chenglin JIAO Pengcheng LU Fenglin ZHANG Hua mnr key laboratory of metallogeny and mineral assessment Institute of Mineral ResourcesChinese Academy of Geological SciencesBeijing 100037China

Lop Nur is located at the eastmost end of the Tarim Basin in Xinjiang,Northwestern *** study reviews the hydrochemical characteristics and evolution of underground brine in Lop Nur,based on analytical data from 429 water samples(mainly brine).It is found that in the NE-SW direction,from the periphery to the Luobei sub-depression,while the hydrochemical type varies from the sodium sulfate subtype(S)to the magnesium sulfate subtype(M),the corresponding brine in the phase diagram transfers from the thenardite phase(Then)area,through the bloedite phase(Blo),epsomite phase(Eps),picromerite phase(Picro),finally reaching the sylvite phase(Syl)*** for the degree of evolution,the sequence is the periphery

关键词： brine evolution isotope enrichment potassium Lop Nur

Geochemistry, Monazite U–Pb Dating, and Li–Nd Isotopes of the Madi Rare Metal Granite in the Northeastern Part of the North China Craton

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Acta Geologica Sinica(English Edition) 2019年第4期93卷 901-911页

作者： HOU Jianglong JIANG Biao DAI Hongzhang mnr key laboratory of metallogeny and mineral assessment Institute of Mineral ResourcesChinese Academy of Geological SciencesBeijing 100037China

The Madi rare metal granite is a complex massif,which contains a variety of rare metals,such as Nb,Ta,Li,and *** this paper,the geochemical characteristics of the granite were obtained by multi-collector inductively coupled mass spectrometry(MC-ICP-MS).The precise crystalline age of the granite was obtained from monazite U-Pb dating,and the source of the granite was determined using Li-Nd *** Madi rare metal granite is a high-K(calc-alkaline),peraluminous,S-type *** U-Pb monazite age indicates that the crystalline age of the granite is 175.6 Ma,which is Early *** granite is characterized by a relatively wide range ofδ7 Li values(+2.99‰to+5.83‰)and high lithium concentrations(181 ppm to 1022 ppm).The lithium isotopic composition of the granite does not significantly correlate with the degree of magmatic *** insignificant amount of lithium isotope fractionation occurred during the granitic *** lithium isotopic composition of the granite significantly differs from that of the wall rock,but it is very similar to that of a primitive mantle peridotite xenolith(meanδ7 Li value+3.5‰).The plot of Li concentration versusδ7 Li indicates that the Li isotopic composition of the granite is similar to that of island arc *** on the above-described evidence,the granite was mainly derived from the crust,but it was contaminated by a deep granitic magma.

关键词： geochemistry U-Pb monazite age Li-Nd isotopes crystallization age magmatic source Madi rare metal granite

The First Discovery of the Early Palaeozoic Carbonatite in the Bayan Obo Deposit, Inner Mongolia, China: Evidence from Zircon U-Pb Geochronology

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Acta Geologica Sinica(English Edition) 2018年第6期92卷 2440-2442页

作者： KE Changhui LI Yike WU Zhongjian mnr key laboratory of metallogeny and mineral assessment Institute of Mineral ResourcesCAGS School of Earth Sciences and resources China University of Geosciences

Objective The Bayan Obo in the northern North China Craton is the world’s largest REE-Nb-Fe deposit. The genesis of its hosted carbonatite is still controversial for sedimentary or igneous(Song et al.,2018). Recent geological exploration, including 1:10000 geological mapping and drilling exploration, have revealed new exposures of zonal distribution of alteration and mineralization, which combined with previous results of isotopical geochemistry indicate the

关键词： Pb Evidence from Zircon U-Pb Geochronology Inner Mongolia China

Re-Os Isotopic Dating of a W-Be Polymetallic Deposit in the Southern Qinling Region, China

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Acta Geologica Sinica(English Edition) 2018年第1期92卷 414-415页

作者： DAI Hongzhang WANG Denghong WANG Chenghui HUANG Fan key laboratory of metallogeny and mineral resource assessment Ministry of Land and ResourcesInstitute of Mineral Resource Chinese Academy of Geological Sciences

Objective In recent years, a series of tungsten prospecting breakthroughs have been made in the southern Qinling Mountains. Especially, a new deposit type with a scheelite -beryl-molybdenite assemblage in the Zhen＇an area of Shaanxi Province was firstly discovered. This deposit is currently in a detailed investigation stage, and no detailed study has been yet conducted. This work selected one molybdenite sample from the Be （W） ores in this deposit for Re-Os isotope measurements to define the time limit of tungsten and beryllium mineralization, and to further reveal the ore-forming geological setting of rare metals in the southern Qinling region.

关键词： Re-Os Isotopic Dating Re-Os Isotopic Dating of a W-Be Polymetallic Deposit the Southern Qinling Region

Apatite Fission Track Ages in the Duolong Ore District and the Uplift Time of the Qiangtang Terrrane, Tibet

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Acta Geologica Sinica(English Edition) 2018年第1期92卷 408-409页

作者： YANG Huanhuan TANG Juxing SONG Yang LIU Zhibo LIN Bin MLR key laboratory of metallogeny and mineral resource assessment Institute of Mineral Resources Chinese Academy of Geological Sciences

Objective Fission track （FT） analysis has developed into one of the most useful techniques throughout the geologic community to reconstruct low-temperature thermal historyof rocks over geological time （Reiners et al., 2005）. The FT method is based on the accumulation of narrow damage trails （i.e., fission tracks） in uranium-rich mineral grains （e.g., apatite, zircon, titanite） and natural glasses, which form as a result of spontaneous nuclear fission decay of 238U in nature. Apatite Fission Track （AFT） has been used in many places in Tibet to study the Qinghai- Tibetan Plateanuplifl-exhumation history. However, few AFT studies have been reported in the Duolong ore district. The Duolong ore district is one of the most important ore districts in the Bangong Co-Nujiang metallogenic belt, Tibet （Lin Bin et al., 2017） and the uplift-exhumation of the Duolong ore district is closely related to the evolution of the Qiangtang Basin. Therefore, AFT of the Duolong ore district will provide important information about the uplift-exhumation history of the Duolong ore district and the Qiangtang Basin.

关键词： Apatite Fission Track Ages the Duolong Ore District the Uplift Time of the Qiangtang Terrrane

The Metallogenetic Regularities of Lithium Deposits in China

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Acta Geologica Sinica(English Edition) 2015年第2期89卷 652-670页

作者： LI Jiankang ZOU Tianren LIU Xifang WANG Denghong DING Xin key laboratory of metallogeny and mineral resource assessment Institute of Mineral ResourcesChinese Academy of Geological Sciences China University of Geosciences

Lithium resources support the development of high-technology industries. China has abundant lithium resources which are mainly distributed in Tibet, Qinghai, Sichuan and Jiangxi. Salt lakes in China have significant lithium reserves, but lithium is mainly produced from hard rock lithium deposits because the extraction from salt lakes requires further improvements. The hard rock lithium deposits mainly occur in granitic pegmatite in the Altay region of Xinjiang and the Jiajika deposit in western Sichuan Province; they mainly formed in the Mesozoic and occurred in a relatively stable stage during orogenic processes. On the basis of the information from 151 lithium deposits or spots, 14 lithium metallogenic series were identified, and granitic pegmatite, granite, and sedimentary types were considered to be the main prediction types of lithium resources. Twelve lithium mineralization belts were divided and a series of maps showing the lithium metallogenetic regularity in China were drawn. We conclude that the hard rock and brine type of lithium resources possibly have a similar lithium source related to magmatism. The mctallogenic features of the lithium in China were related with the distinct history of tectonic-magmatic activity in China. This study benefits the assessment of, and prospecting for, lithium resources in China.

关键词： lithium deposit prediction type of lithium resources metallogenetic regularity metallogenic series pegmatite

Measurements of Sulfur Isotope Composition on Ultrasmall(80 Nanomole) Sulfide and Sulfate Samples by a Modified EA-IRMS

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Acta Geologica Sinica(English Edition) 2022年第5期96卷 1792-1799页

作者： WU Xiaopei FAN Changfu HU Bin GAO Jianfei LI Yanhe mnr key laboratory of metallogeny and resource assessment Institute of Mineral ResourcesCAGSBeijing 100037China School of Earth and Space Sciences Peking UniversityBeijing 100871China

The traditional method for sulfur isotope measurement using EA-IRMS commonly requires sulfur content greater than 2 μmol. Such a large sample size limits its application to low-S materials, the size mainly being due to ineffective utilization of sample gas, almost 99.7% of which is discarded with carrier gas through the split port of the continuous-flow interface. A modified EA-IRMS system with a gas chromatographic(GC) column and a custom-built cryogenic concentration device is used in this study. We measured six reference materials to test the performance of this method. The results were consistent with those obtained through traditional EA-IRMS. Precisions ranging from ±0.24‰ to ±0.76‰(1σ)can be obtained with samples equivalent to ~80 nmol sulfur, which were similar to results obtained from an alternative method using an absorption column. Our improved method is a powerful tool for sulfur isotope measurement in ultrasmall sulfide and sulfate samples, which can be further applied to carbon, nitrogen and oxygen isotope analyses of samples at about 100 nmol level.

关键词： sulfur isotopes ultrasmall sample cryogenic concentration EA-IRMS

Provenance of Conglomerate and Sandstone from Early Permian Shoushangou Formation in Xi Ujimqin,Inner Mongolia:Implications for Understanding Paleo-Asian Ocean Subduction

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Acta Geologica Sinica(English Edition) 2024年第1期98卷 10-31页

作者： ZHANG Yingli GUO Xianqing MA Shouxian mnr key laboratory of metallogeny and mineral assessment Institute of Mineral ResourcesCAGSBeijing 100037China Chinese Academy of Geological Sciences Beijing 100037China

During the Late Carboniferous to Early Permian,a rift was formed by post-collisional extension after ocean closure or an island arc-related basin formed by Paleo-Asian Ocean(PAO)subduction in the Xi Ujimqin ***,the closure time of the PAO is still under ***,to identify the origin of the PAO,the geochemistry and U-Pb age of zircons were analyzed for the extra-large deep marine,polymict clastic boulders and sandstones in the Shoushangou Formation within the *** analyses revealed magmatic activity and tectonic *** conglomerates include megaclasts of granite(298.8±9.1 Ma)and granodiorite porphyry(297.1±3.1 Ma),which were deposited by muddy debris *** of this study demonstrated that the boulders of granitoids have the geochemistry of typical I-type granite,characterized by low Zr+Nb+Ce+Y and low Ga/Al *** granitoid boulders were formed in island arc setting,indicating the presence of arc magmatism in the area that is composed of the Late Carboniferous to Early Permian subduction-related granitoid in southern Xi *** diagrams for determining sedimentary provenance using major and trace elements indicate that Shoushangou sediments originated from continental island arc-related felsic *** zircon U-Pb age cluster of 330–280 Ma was obtained,indicating input from granite,ophiolite,Xilin Gol complex,and Carboniferous sources to the *** basin was geographically developed behind the arc during the Early Permian period because the outcropped intrusive rocks in the Late Carboniferous to Early Permian form a volcanic *** comprehensive analyses of source areas suggest that Shoushangou sediments developed in a backarc basin in response to the northward subduction of the *** backarc basin and intrusive rocks,in addition to previously published Late Carboniferous to Early Permian magmatic rocks of arc unit in Xilin Gol,confirm the presence of an Early Permian trencharc-basin system in the region,r

关键词： provenance analysis backarc basin Shoushangou Formation Early Permian Central Asian Orogenic Belt

Constraints on the Archean atmospheric oxygen and sulfur cycle from mass-independent sulfur records from Anshan-Benxi BIFs, Liaoning Province, China

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Science China Earth Sciences 2007年第10期50卷 1471-1478页

作者： HOU KeJun1,2, LI YanHe1,2? & WAN DeFang1,2 1 key laboratory of metallogeny and mineral resource assessment, Institute of mineral resource, Chinese Academy of Geological Sciences (CAGS), Beijing 100037, China 2 key laboratory of Isotope Geology, CAGS, Beijing 100037, China key laboratory of metallogeny and mineral resource assessment Institute of Mineral Resource Chinese Academy of Geological Sciences (CAGS) Beijing China key laboratory of Isotope Geology CAGS Beijing China

The Archean atmospheric oxygen concentration and sulfur cycle was long debated. The banded iron formation (BIF) is a special type of the sedimentary formation, which has truly recorded the atmospheric and oceanic conditions at that time. In this study, the composition of multiple sulfur isotope (δ 34S/δ 33S/δ 32S) for sulfides bedded in the Archean (~2.7 Ga) BIFs, in Anshan-Benxi area of Liaoning Province has been measured. The value of △33S varies from -0.89‰ to +1.21‰, which shows very obvious mass-independent fractionation (MIF) signatures. These non-zero △33S values indicate that the Archean sulfur cycles are different from what it is today, which have been deeply influenced by gas phase photochemical reactions. Algoma-type BIFs which are closely related to the volcanic activity have negative △33S value, however, Superior-type BIFs which are far away from the volcanic center have positive △33S value. The δ 34S varies in a large range from -22.0‰ to +11.8‰, which indicates that the bacteria reduction activity has already existed at that time, and that the oceanic sulfate concentration has at least reached 1 mmol/L in local areas. Combined with the contemporaneous existence of the hematite, magnetite and the occurrence and preservation of the sulfur MIF, it can be inferred that the Archean atmospheric oxygen level must be at 10-2―10-3 of the present atmospheric level (PAL).

关键词： sulfur mass-independent fractionation, Anshan-Benxi area, BIF, Archean atmospheric oxygen level, Archean sulfur cycle