扬子地块北缘大型钡成矿带中硫同位素组成及其意义

钡以BaSO4形式存在的重晶石矿床在世界上分布广泛,但以BaCO3形式存在的毒重石矿床极为罕见。在扬子地块北缘大巴山一带的早古生代硅岩建造中,发育大量层状毒重石和重晶石矿床,两类矿床在空间上表现出既共生又分离的分布规律,构成世界上极为独特的大型钡成矿带。本文研究了钡成矿带中的硫同位素组成特点,结果显示,在以毒重石矿石为主的成矿亚带中,重晶石样品的δ^34S值相对较低,变化范围较小（22．1‰～37．0‰）,平均27．3‰（n=11）,基本上与寒武纪海水硫酸盐的δ^34S值（δ^34S=27～32‰）接近或略低。反映了形成重晶石的硫来自海水,并有可能经历了热化学的硫酸盐还原作用;与毒重石共生的重晶石形成与热液流体有密切关系。在以重晶石为主的成矿亚带中,重晶石样品的δ^34S值相对较高,变化范围较宽（33．4‰～57．6‰）,平均43．5‰（n=31）。与寒武纪海水硫酸盐δ^34S值相比发生了大的改变,反映了与同期海水硫酸盐相关的重硫的强烈富集。这种高正值特点超过了地史中海水硫酸盐的最高值,说明重晶石的形成与生物作用密切相关。强烈的重硫富集,归因于硫酸盐还原菌的活动。     

湘黔新晃-天柱重晶石矿床微量稀土元素和硫同位素研究

湘黔新晃-天柱地区的早寒武世重晶石成矿带是世界上最大的重晶石矿集区,在全球范围内具有代表性,对其进行 研究具有重要的科学意义。本文通过对新晃-天柱地区的重晶石矿床微量稀土元素和硫同位素研究表明：所有样品的 、比值以及重晶石含矿岩系稀土元素具有明显的负异常表明重晶石矿床形成时处于缺氧还原环境;重晶石矿石 表现出明显的正异常,反映了成矿过程受到了较强的海底热液物质的影响,表明钡可能主要来自于海底热液喷流物质; 重晶石的δ3值主要分布在,表现出重硫富集的特征,且重晶石硫同位素呈塔式分布,表明硫源来源单一,主 要来自同期海水硫酸盐。黄铁矿δ3值低于同期海水硫同位素组成,表明生物细菌对海水硫酸盐的还原起到了很大作用, 并且反映了矿床形成于海水交换有限的滞留的海盆系统。综合以上分析认为重晶石成矿时期为海底缺氧、热液活动频繁、 封闭半封闭的台地泻湖环境。     

云南会泽铅锌矿田硫同位素研究

为探讨会泽铅锌矿田成矿流体总硫同位素组成、成矿温度、硫源及还原硫的形成机制,在分析前人的硫同位素数据基础上对麒麟厂矿床上部原生矿体硫化物(黄铁矿、闪锌矿和方铅矿)及麒麟厂和矿山厂矿床外围新发现的硫酸盐矿物(重晶石)进行了硫同位素研究。结果显示,原生矿体中的硫化物的δ34S变化为8.0‰~17.68‰,成矿流体中硫同位素已达分馏平衡;矿床外围的硫酸盐δ34S变化为17.95‰~24.30‰。利用共生矿物对Pinckney法,估算获得成矿流体的δ34SΣS为14.44‰,与海相硫酸盐的δ34S相近;通过同位素地质温度计,估算获得成矿温度为134~388℃;包裹体测温发现,重晶石为热液成因,暗示成矿流体中的硫可能来自矿区及矿区外围各个地层的海相硫酸盐或是矿区发现的热液重晶石。硫酸盐的还原机制应为热化学还原作用(TSR)。     

中国主要类型锑矿床硫同位素组成及地球化学特征

中国主要类型锑矿床的硫同位素组成范围变化很大,锑矿床中各种矿物（辉锑矿、黄铁矿、闪锌矿、雄黄、方铅矿、重晶石、毒砂、辰砂、脆硫锑铅矿）的δ３４Ｓ值从－３２．７‰变化到＋３４．８‰,极差值高达６７．５‰。各类锑矿床中矿物的硫同位素组成变化各异,说明锑矿床成因较复杂,硫的来源不仅有海水中沉淀的硫酸盐硫,而且还有生物、细菌形式的还原硫和深源硫（岩浆作用、喷流作用等）,从而形成不同类型或成因复杂的锑矿床     

云南金沙厂铅锌矿床硫同位素地球化学特征

金沙厂铅锌矿床位于云南省东北部,川-滇-黔铅锌成矿域的西北部,矿体主要赋存于下寒武统和上震旦统的碳酸盐地层中。该矿床的主要矿石矿物是闪锌矿和方铅矿,主要脉石矿物是重晶石、萤石和石英。闪锌矿的δ34S值分布于3.9‰～11.2‰之间,平均为5.7‰;方铅矿的δ34S值在6.0‰～9.0‰之间,平均为7.1‰;两个重晶石的δ34S值分别为34.8‰和34.5‰。重晶石的δ34S值与下寒武地层硫酸盐的一致,排除其他可能来源,认为重晶石的硫来源于下寒武统地层。硫化物的硫不可能来自细菌硫酸盐还原作用,因为流体包裹体均一温度远高于细菌的存活温度。硫酸盐热化学还原作用产生的同位素分馏至多为20‰,由此可知下寒武统地层中硫酸盐发生热化学还原作用产生的还原硫δ34S值至少应为14‰,这个值远高于该矿床硫化物δ34S值,因此这种机制不是还原硫的唯一来源。矿区周围广泛分布玄武岩,并且与岩浆有关的硫化物δ34S值比较低,所以硫化物中的硫可能来自岩浆活动。在方铅矿和闪锌矿共生的样品中,闪锌矿的δ34S值大于方铅矿的δ34S值,说明成矿流体的硫同位素局部达到平衡。利用矿物对硫同位素组成计算的硫化物平衡温度与流体包裹体均一温度一致。     

云南建水荒田一虾洞火山岩型银多金属矿带的硫,铅同位素特征及？…

火山岩型银多金属矿床是滇东南地区的重要矿床类型、矿床中硫的δ＾３４Ｓ值分布于－６．９‰－＋７．３‰之间,并且呈波浪式分布;铅同位素组成以正常铅为主,并受异常铅的混染。硫,铅同位素具有相似的变化趋势。这些硫,铅同位素特征表明,该矿床成矿物质可能具有多种来源,除了直接来自玄武岩外,还有来自古海水硫酸盐和地层的贡献;该矿床的成因与玄武岩海底中心喷发有密切的关系。     

青海锡铁山铅锌矿床硫同位素地球化学研究——深源与海水硫的混合

锡铁山铅锌矿床发育较为完整的喷流沉积系统,包括管道相、近喷口相、远端沉积相及各种喷流沉积岩,并有后期改造作用形成的脉状铅锌矿体。本文通过喷流沉积系统各部位硫化物硫同位素的分析,不同部位硫化物硫同位素组成不同,且规律性变化。以黄铁矿分析结果为例,网脉状石英钠长岩δ34S=+0.8‰,代表供给系统的硫化物脉2.95‰,非层状矿体4.48‰,层状矿体3.25‰,炭质片岩为+6.26‰,后期改造型铅锌矿脉为+2.93‰。代表管道相的网脉状石英钠长岩黄铁矿具有深源(幔源)的硫同位素组成,而矿体或大理岩上盘炭质片岩具有海水硫来源的特点。矿体的硫介于二者之间,更靠近炭质片岩的硫化物同位素组成,其来源可能更多受海水硫酸盐的制约,即锡铁山矿床硫具有混合来源性质,主要是海水硫酸盐的还原,部分来源于深部卤水的供给。硫的还原方式以生物细菌还原为主。层状矿体中硫同位素组成由早至晚δ34S逐渐降低,表明层状矿体成矿作用过程中,发生了生物成因的H2S的大量加入。     

与火山岩容矿有关的海底热水沉积矿床硫同位素地球化学证据

对国内与火山岩容矿有关的海底热水沉积矿床新疆阿巴宫、铁-铅锌矿、甘肃桦树沟铁-铜矿床、新疆阿舍勒铜锌矿、新疆阿尔泰可可塔勒铅锌矿等矿床硫化物进行硫同位素测定,这些矿床硫化物和硫酸盐的硫同位素组成分别为-4.3‰~1‰(阿巴宫)、+8.1‰~+33.4‰(桦树沟)、-3.3‰~+8.2‰(阿舍勒矿床硫化物)、-20.6‰~5.1‰(阿尔泰可可塔勒)。硫化物的硫同位素变化范围较小,硫同位素可以达到平衡,也可以没有达到平衡,获得的δ34SΣS值有+18‰~29‰之间,δ34SΣS值高;表明与火山岩控矿有关的海底热水沉积矿床热液中硫的来源,不是直接来源岩浆去气的硫,而是岩浆去气硫与海水硫酸盐硫混合而成的硫。     

云南普洱萝卜山铅锌矿床成矿流体中硫的来源与形成机制

萝卜山铅锌矿床位于三江成矿带南段的思茅盆地,在该盆地沉积岩容矿的铅锌矿床中具有典型代表性。本次工作对该矿床原生矿体主要矿石矿物(黄铁矿、方铅矿和闪锌矿)进行了硫同位素组成分析,探讨了成矿流体中硫的来源和形成机制。结果表明,矿床δ34S值在-8.83‰~1.61‰之间,与典型幔源硫(-3‰~3‰)特征不同,与区域上海相蒸发岩的硫同位素组成(15‰~25‰)也不同。萝卜山铅锌矿床成矿流体中的硫可能主要来源于海水硫酸盐,形成机制为细菌还原(BSR)。     

黔西北铅锌矿床硫同位素地球化学研究

位于扬子地块西南缘的川滇黔铅接壤区,是我国独具特色的铅锌银多金属矿集区,黔西北铅锌矿床是其重要的组成部分。黔西北铅锌成矿区内业已发现铅锌矿床(点)100余处,其赋矿围岩为泥盆至二叠系白云岩或白云质灰岩,而其分布严格受到三条区域性构造带的控制,其中大部分矿(化)体产于北西向褶皱+断裂构造体系中。在系统收集前人发表的有关矿床硫同位素数据基础上,对成矿流体中硫的来源及形成机制进行了详细的探讨。11个矿床的150件硫化物硫同位素组成介于+3.5‰⁺20.3‰,多数集中在+6‰+20.3‰,多数集中在+6‰⁺20‰分布,峰值处于+10‰+20‰分布,峰值处于+10‰⁺14‰,具有明显的塔式正态分布特征。可见硫化物明显富集重硫同位素,与在0‰附近的陨石硫不同。前人研究发现泥盆至二叠系沉积地层中,普遍发育膏盐层,其中硫酸盐硫同位素组成介于+12‰+14‰,具有明显的塔式正态分布特征。可见硫化物明显富集重硫同位素,与在0‰附近的陨石硫不同。前人研究发现泥盆至二叠系沉积地层中,普遍发育膏盐层,其中硫酸盐硫同位素组成介于+12‰⁺28‰,与泥盆至二叠纪海水硫酸盐硫同位素组成相似(+18‰+28‰,与泥盆至二叠纪海水硫酸盐硫同位素组成相似(+18‰⁺30‰)。硫酸盐热化学还原(TSR)可以使体系中的硫同位素组成降低15‰,因此,黔西北铅锌矿床成矿流体中的还原硫主要是TSR的产物,即蒸发岩是主要的硫源。     

贵州天柱大河边铅锌矿床的发现及其意义

大河边重晶石矿床是一个世界级的超大型重晶石矿床。最近在该区重晶石矿床下部的震旦系陡山沱组碳酸盐岩(白云岩)和碎屑岩中,新发现一套规模较大、层位产出稳定的铅锌矿化。铅锌矿体和重晶石矿床具有"上部为重晶矿,下部为铅锌硫化物矿床"的矿化特征。铅锌矿段矿石矿物主要为闪锌矿、黄铁矿及方铅矿,含少量白铁矿、黄铜矿及磁黄铁矿;脉石矿物主要为石英和重晶石,少量白云石、热液磷灰石、炭沥青及钡冰长石。成矿流体特征类似于形成沉积喷流型铅锌矿床的流体特征。铅锌矿化中的硫源自局限海盆内早寒武世海水经硫酸盐还原作用提供。此种类似于喷流沉积型铅锌矿床在南华裂谷盆地一带矿化层位稳定、分布范围较广泛,体现早寒武世时在裂谷盆地内存在一次大规模的热液事件。天柱大河边铅锌矿床的发现具有重要的资源意义及区内该种矿床的勘查意义。     

Rare earth element and stable isotope (O, S) geochemistry of barite from the Bijgan deposit, Markazi Province, Iran

The Bijgan barite deposit, which is located northeast of Delijan in Markazi Province of Iran, occurs as a small lenticular body at the uppermost part of an Eocene volcano-sedimentary rock unit. The presence of fossiliferous and carbonaceous strata suggests that the host rocks were deposited in a quiet marine sedimentary environment. Barite, calcite, iron oxides and carbonaceous clay materials are found as massive patches as well as thin layers in the deposit. Barite is marked by very low concentrations of Sr (1–2%) and total amounts of rare earth elements (REEs) (6.25–17.39?ppm). Chondrite-normalized REE patterns of barite indicate a fractionation of light REEs (LREEs) from La to Sm, similar to those for barite of different origins from elsewhere. The La_CN/Lu_CN ratios and chondrite-normalized REE patterns reveal that barite in the Bijgan deposit is enriched in LREE relative to heavy rare earth elements (HREEs). The similarity between the Ce/La ratios in the barite samples and those found in deep-sea barite supports a marine origin for barite. Lanthanum and Gd exhibit positive anomalies, which are common features of marine chemical sediments. Cerium shows a negative anomaly in most samples that was inherited from the negative Ce anomaly of hydrothermal fluid that mixed with seawater at the time of barite precipitation. The δ¹⁸O values of barites show a narrow range of 9.1–11.4‰, which is close to or slightly lower than that of contemporaneous seawater at the end of the Eocene. This suggests a contribution of oxygen from seawater in the barite-forming solution. The δ³⁴S values of barites (9.5–15.3‰) are lower than that of contemporaneous seawater, which suggests a contribution of magmatic sulfur to the ore-forming solution. The oxygen and sulfur isotope ratios indicate that submarine hydrothermal vent fluids are a good analog for solutions that precipitated barite, due to similarities in the isotopic composition of the sulfates. The available data including tectonic setting, host rock characteristics, REE geochemistry, and oxygen and sulfur isotopic compositions support a submarine hydrothermal origin for the Bijgan barite deposit. At the seafloor, barite deposition occurred where ascending Ba-bearing hydrothermal fluids encountered seawater. Sulfate was derived from the sulfate-bearing marine waters, and, to a lesser extent, by oxidized H₂S, which was derived from magmatic hydrothermal fluids.     

西藏甲玛铜多金属矿硫同位素地球化学研究

西藏墨竹工卡县甲玛铜多金属矿床位于冈底斯成矿带东段,Cu、Mo、Pb+Zn、Au、Ag均达大型规模,并伴生Co、Bi、W、Ni等多金属矿化。黄铜矿、斑铜矿、辉钼矿、方铅矿、闪锌矿、黝铜矿、辉铜矿等硫化物为主要的矿石矿物,硫酸盐矿物以硬石膏为主,含矿岩浆岩以花岗斑岩、二长花岗斑岩和花岗闪长斑岩为主。通过对甲玛矿区主要硫化物和硬石膏的硫同位素分析,并结合前人研究,甲玛矿区硫化物的硫同位素δ34S值变化于13.6‰～+12.5‰,平均值1.33‰(样品数86)、硬石膏δ34S值+0.5‰～+1.8‰,平均值+1.13‰(样品数3)、岩浆岩δ34S值0.7‰～0.2‰,平均值0.5‰(样品数3),与岩浆硫δ34S值0±3‰一致。闪锌矿-方铅矿-黄铜矿矿物对的硫同位素地质温度计,显示成矿温度为408～433℃,说明其形成时硫同位素处于平衡状态。冈底斯成矿带上的驱龙等斑岩型矿床中硫化物和岩浆岩硫同位素,均具有δ34S值变化范围小,平均值接近0值,与岩浆硫特征一致的特点,反映了甲玛铜多金属矿床具有矽卡岩-斑岩型矿床硫同位素地球化学特征,硫以岩浆来源为主。     

若干以沉积岩为容矿围岩的热液矿床硫同位素地球化学研究

文章对与沉积岩容矿有关的热液广西高龙微细浸染型金矿、新疆霍什布拉克铅锌矿、广西盘龙铅锌矿和下雷锰矿等矿床硫化物进行硫同位素测定,硫同位素组成分别为-15.3‰~+15.6‰,-18.8‰~+24.2‰,-21.0‰~+26.4‰,-32.6‰~+32.2‰。硫同位素可以达到平衡(高龙、霍什布拉克、下雷),也可以没达到平衡(盘龙)。δ34SΣS值在+13‰~+28‰之间,表明与沉积岩容矿热液矿床中硫来源于海水硫酸盐还原硫,但不排除有岩浆硫的加入。     

天柱大河边重晶石矿床铅同位素特征及来源探讨

对取自天柱大河边重晶石矿床的重晶石样品和含方铅矿黑色页岩样品进行了铅同位素测定与研究.结果表明,在 Zartman铅构造模式图中,重晶石矿石、含方铅矿黑色页岩和黑色页岩有大致相同的铅同位素分布区,均沿上地壳铅演化线分布,表明它们之间具有同源关系;重晶石矿石及其赋矿黑色页岩的铅同位素组成与基底地层的铅同位素组成在 Zartman铅构造模式图中具有完全不同的分布范围,表明重晶石矿石中的铅不大可能来源于基底地层;结合重晶石矿石及其赋矿黑色页岩的铅同位素组成在 Zartman铅构造模式图和Δγ-Δβ铅来源分类图的分布,天柱大河边重晶石矿床的铅主要具上地壳铅、壳幔混合的俯冲带铅和热水沉积作用铅的混合来源特点,这为天柱大河边重晶石矿床的热水沉积成因提供了铅同位素证据.     

Discovery of an abnormally high-δ34S barite deposit and a new understanding of global sulfur isotope variation during geological history

The evolution of the global sulfur isotope curve was plotted based on the δ34S values of evaporates resultant from oceanic evaporation. In the long period of geological history the δ34S values showed obvious peaks for three times during the process of ancient oceans’ sulfur isotope evolution, namely the Early Cambrian (+30‰), the Late Devonian (+25‰) and the Permian-Triassic transition interval (+17‰), but the causes of the abnormal rise of sulfur isotopic values during the geological period are still in question. In this paper, 18 samples collected from a large Devonian barite deposit from Zhenning County were analyzed to determine their δ34S values, revealing that the 18 samples have very high δ34S values (δ34S=41.88‰-+68.39‰), with an average close to 56.30‰, which are higher than the isotopic values of contemporary sulfates (+17‰- +25‰). A comparative analysis was conducted of the emerging of high δ34S barite deposits (from Cambrian and Devonian) and the δ34S variation curves of the ancient oceans. The results indicate that the time when the obvious peaks of δ34S values appeared and the time of massive sedimentation of high δ34S barite deposits are very close to each other, which, in our opinion, is not a coincidence. There may exist some correlations between the sulfur isotope evolution of ancient oceans during the diverse periods of geological history and the massive sedimentation of high δ34S barite deposits. Therefore, it is inferred that perhaps it was the massive sedimentation of high δ34S barites that caused the sharp rise of δ34S values in a short period of time.     

Mineralogy,Sulfur Isotope and Fluid Inclusion Studies of Hydrothermal Ore at the Hakurei Deposit,Bayonnaise Knoll,Izu‐Bonin Arc

Sulfide and sulfate ore samples collected from the Hakurei deposit of the Bayonnaise knoll were examined for the occurrence and chemical composition of minerals, including the sulfur isotopes and the microthermometry of fluid inclusions. Massive sulfide ore, mineralized volcanic rock, and anhydrite ore occur in descending order, from the seafloor to the bottom of the cored sample. The massive sulfide ore is dominated by sphalerite and accompanied by tennantite, chalcopyrite, and pyrite with lesser amounts of galena, enargite, and covellite. Amorphous silica is commonly precipitated on the surface of the sulfide minerals. As‐bearing minerals such as tennantite, enargite, and luzonite are common, while galena and Sb‐rich tetrahedrite are scarce. The mineral abundance and chemical composition of the minerals differs from that found in chimneys of the deposit. The sulfur isotope compositions in the minerals are +3.1–5.2‰ for sulfides and +19.6–21.8‰ for sulfate minerals. The homogeneous nature of the sulfur isotopes suggests that sulfur incorporated in the Hakurei deposit came from the reduction of aqueous sulfate in seawater.     

Isotopic Compositions of Sulfur in the Jinshachang Lead–Zinc Deposit, Yunnan, China, and its Implication on the Formation of Sulfur-Bearing Minerals

The Jinshachang lead–zinc deposit is mainly hosted in the Upper Neoproterozoic carbonate rocks of the Dengying Group and located in the Sichuan–Yunnan–Guizhou(SYG) Pb–Zn–Ag multimetal mineralization area in China.Sulfides minerals including sphalerite,galena and pyrite postdate or coprecipitate with gangue mainly consisting of fluorite,quartz,and barite,making this deposit distinct from most lead–zinc deposits in the SYG.This deposit is controlled by tectonic structures,and most mineralization is located along or near faults zones.Emeishan basalts near the ore district might have contributed to the formation of orebodies.The δ34S values of sphalerite,galena,pyrite and barite were estimated to be 3.6‰–13.4‰,3.7‰–9.0‰,6.4‰ to 29.2‰ and 32.1‰–34.7‰,respectively.In view of the similar δ34S values of barite and sulfates being from the Cambrian strata,the sulfur of barite was likely derived from the Cambrian strata.The homogenization temperatures(T ≈ 134–383°C) of fluid inclusions were not suitable for reducing bacteria,therefore,the bacterial sulfate reduction could not have been an efficient path to generate reduced sulfur in this district.Although thermochemical sulfate reduction process had contributed to the production of reduced sulfur,it was not the main mechanism.Considering other aspects,it can be suggested that sulfur of sulfides should have been derived from magmatic activities.The δ34S values of sphalerite were found to be higher than those of coexisting galena.The equilibrium temperatures calculated by using the sulfur isotopic composition of mineral pairs matched well with the homogenization temperature of fluid inclusions,suggesting that the sulfur isotopic composition in ore-forming fluids had reached a partial equilibrium.     

黔东松桃地区南华系大塘坡组锰矿中黄铁矿硫同位素特征及其地质意义

黔东松桃地区是我国重要的锰矿富集区,其中大塘坡组中黄铁矿δ34S存在比较大的差异.通过CF-IRSM法对松桃李家湾、道坨、西溪堡矿区菱锰矿样品中黄铁矿硫同位素组成开展研究,结果显示出两个明显的特征:(1) 样品中黄铁矿普遍具有极高的δ34S值,为47.69‰~66.76‰;(2) 在同一成锰盆地中,水深相对较浅的李家湾矿区黄铁矿δ34S值(47.69‰~59.15‰)明显低于水深相对较深的道坨矿区的δ34S值(53.85‰~62.86‰),且中心相δ34S的值(53.85‰~66.76‰)明显高于过渡相δ34S的值(47.69‰~59.15‰),黄铁矿硫同位素组成表现出明显的深度梯度效应.大塘坡组含锰层位黄铁矿异常高的δ34S值及其明显的深度梯度特征表明,在新元古代Sturtian冰期刚刚结束的间冰期初期,海水硫酸盐浓度极低,海洋呈现显著的分层现象,这一时期深部海洋可能并没有完全氧化.      

元素分析仪-气体同位素质谱法分析硫酸钙样品的硫同位素组成

硫酸盐硫同位素的常规分析方法是将硫酸盐转化为硫酸钡后搭配双路进样SO2法,该法易于操作、数据稳定,但样品用量大、费时费力,需要繁杂的前处理,无法满足微量分析发展方向的需求。本文以石膏为例,以元素分析仪-气体同位素质谱法(EA-IRMS)直接测定硫酸钙样品硫同位素比值,对同一样品分别采用:①硫酸钙与V2O5混合后包裹于锡杯中密封,直接进行元素分析仪-气体同位素质谱分析;②硫酸钙充分溶于去离子水中,向溶有硫酸钙样品的液体中加入沉淀试剂BaCl2,将生成的硫酸钡沉淀滤出后,用去离子水清洗2~3遍,烘干后与V2O5混合包裹于锡杯中密封再进行质谱测定。实验选取了13件δ34S值变化范围介于-20‰^+30‰之间的天然石膏样品,将获得的硫同位素比值进行对比,二者δ34SV-CDT绝对差值在0.00‰~0.24‰,表明同一样品的硫同位素比值结果在误差范围内基本一致。与常规分析方法相比,本文建立的直接在线分析时无需任何化学前处理,只需直接加入适量的V2O5,V2O5和氧气中的外部氧在瞬间燃烧的过程中替代了硫酸钙本身的氧,生成的SO2气体的氧是均一的,其硫同位素比值能代表样品的硫同位素组成,无需进行氧同位素的校正。经过验证表明,硫酸钙样品的直接在线分析是完全可行的。