Huiji Zhao , Yanchao Han , Rucao Li , Xiao-Lei Wang , Yuzhou Feng , Chengming Wang , Shitao Zhang
{"title":"沉积黄铁矿原位硫同位素结果的代表性:示踪成矿流体的意义","authors":"Huiji Zhao , Yanchao Han , Rucao Li , Xiao-Lei Wang , Yuzhou Feng , Chengming Wang , Shitao Zhang","doi":"10.1016/j.oregeorev.2025.106811","DOIUrl":null,"url":null,"abstract":"<div><div>The sulfur isotopic composition of sedimentary pyrite is frequently measured and compared with that of ore stage sulfides to assess the contribution of sulfur from sedimentary pyrite. In-situ analysis methods, notably secondary ion mass spectrometry (SIMS) and laser ablation multi-collector inductively coupled plasma mass spectrometry (LA-MC-ICP-MS), are both efficient and convenient for determining the sulfur isotopic composition of sedimentary pyrite and have been widely used in recent studies.</div><div>However, the representativeness of in-situ analysis results has rarely been investigated. In this study, we investigate this topic by analyzing sedimentary pyrite using SIMS. The samples were collected from the Meishan section in South China. The results show that framboidal and euhedral pyrite tend to have low and elevated δ<sup>34</sup>S values, respectively. The average δ<sup>34</sup>S value obtained by SIMS analysis is generally higher (up to ∼15 ‰) than that derived using bulk analysis in which pyrite was extracted using chromium reduction method. Since LA-MC-ICP-MS employs a larger spot size (25–50 μm), and only euhedral pyrite typically has a relatively large diameter, LA-MC-ICP-MS analysis would like yield even higher δ<sup>34</sup>S values than SIMS. This suggests that in-situ sulfur isotopic results may not be fully representative of the sulfur isotopic composition of sedimentary pyrite.</div><div>A compilation of reported in-situ sulfur isotopic compositions of pyrite in the sedimentary host rocks in the “Golden Triangle” area shows that the average δ<sup>34</sup>S value (∼+9‰) is significantly higher than those obtained through bulk analysis from South China and globally (<−10 ‰), which is consistent with observation at Meishan.</div><div>Consequently, we suggest that combining bulk analysis, in which all the sulfur was extracted, with in-situ method, which provides sulfur isotopic compositions with detailed textural and temporal contexts, offers the most robust interpretation when tracing the source of sulfur in the ore-forming fluids.</div></div>","PeriodicalId":19644,"journal":{"name":"Ore Geology Reviews","volume":"185 ","pages":"Article 106811"},"PeriodicalIF":3.6000,"publicationDate":"2025-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"The representativeness of in-situ sulfur isotopic results for sedimentary pyrite: Implications for tracing ore-forming fluids\",\"authors\":\"Huiji Zhao , Yanchao Han , Rucao Li , Xiao-Lei Wang , Yuzhou Feng , Chengming Wang , Shitao Zhang\",\"doi\":\"10.1016/j.oregeorev.2025.106811\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><div>The sulfur isotopic composition of sedimentary pyrite is frequently measured and compared with that of ore stage sulfides to assess the contribution of sulfur from sedimentary pyrite. In-situ analysis methods, notably secondary ion mass spectrometry (SIMS) and laser ablation multi-collector inductively coupled plasma mass spectrometry (LA-MC-ICP-MS), are both efficient and convenient for determining the sulfur isotopic composition of sedimentary pyrite and have been widely used in recent studies.</div><div>However, the representativeness of in-situ analysis results has rarely been investigated. In this study, we investigate this topic by analyzing sedimentary pyrite using SIMS. The samples were collected from the Meishan section in South China. The results show that framboidal and euhedral pyrite tend to have low and elevated δ<sup>34</sup>S values, respectively. The average δ<sup>34</sup>S value obtained by SIMS analysis is generally higher (up to ∼15 ‰) than that derived using bulk analysis in which pyrite was extracted using chromium reduction method. Since LA-MC-ICP-MS employs a larger spot size (25–50 μm), and only euhedral pyrite typically has a relatively large diameter, LA-MC-ICP-MS analysis would like yield even higher δ<sup>34</sup>S values than SIMS. This suggests that in-situ sulfur isotopic results may not be fully representative of the sulfur isotopic composition of sedimentary pyrite.</div><div>A compilation of reported in-situ sulfur isotopic compositions of pyrite in the sedimentary host rocks in the “Golden Triangle” area shows that the average δ<sup>34</sup>S value (∼+9‰) is significantly higher than those obtained through bulk analysis from South China and globally (<−10 ‰), which is consistent with observation at Meishan.</div><div>Consequently, we suggest that combining bulk analysis, in which all the sulfur was extracted, with in-situ method, which provides sulfur isotopic compositions with detailed textural and temporal contexts, offers the most robust interpretation when tracing the source of sulfur in the ore-forming fluids.</div></div>\",\"PeriodicalId\":19644,\"journal\":{\"name\":\"Ore Geology Reviews\",\"volume\":\"185 \",\"pages\":\"Article 106811\"},\"PeriodicalIF\":3.6000,\"publicationDate\":\"2025-07-26\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Ore Geology Reviews\",\"FirstCategoryId\":\"89\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S0169136825003713\",\"RegionNum\":2,\"RegionCategory\":\"地球科学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q1\",\"JCRName\":\"GEOLOGY\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Ore Geology Reviews","FirstCategoryId":"89","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0169136825003713","RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"GEOLOGY","Score":null,"Total":0}
The representativeness of in-situ sulfur isotopic results for sedimentary pyrite: Implications for tracing ore-forming fluids
The sulfur isotopic composition of sedimentary pyrite is frequently measured and compared with that of ore stage sulfides to assess the contribution of sulfur from sedimentary pyrite. In-situ analysis methods, notably secondary ion mass spectrometry (SIMS) and laser ablation multi-collector inductively coupled plasma mass spectrometry (LA-MC-ICP-MS), are both efficient and convenient for determining the sulfur isotopic composition of sedimentary pyrite and have been widely used in recent studies.
However, the representativeness of in-situ analysis results has rarely been investigated. In this study, we investigate this topic by analyzing sedimentary pyrite using SIMS. The samples were collected from the Meishan section in South China. The results show that framboidal and euhedral pyrite tend to have low and elevated δ34S values, respectively. The average δ34S value obtained by SIMS analysis is generally higher (up to ∼15 ‰) than that derived using bulk analysis in which pyrite was extracted using chromium reduction method. Since LA-MC-ICP-MS employs a larger spot size (25–50 μm), and only euhedral pyrite typically has a relatively large diameter, LA-MC-ICP-MS analysis would like yield even higher δ34S values than SIMS. This suggests that in-situ sulfur isotopic results may not be fully representative of the sulfur isotopic composition of sedimentary pyrite.
A compilation of reported in-situ sulfur isotopic compositions of pyrite in the sedimentary host rocks in the “Golden Triangle” area shows that the average δ34S value (∼+9‰) is significantly higher than those obtained through bulk analysis from South China and globally (<−10 ‰), which is consistent with observation at Meishan.
Consequently, we suggest that combining bulk analysis, in which all the sulfur was extracted, with in-situ method, which provides sulfur isotopic compositions with detailed textural and temporal contexts, offers the most robust interpretation when tracing the source of sulfur in the ore-forming fluids.
期刊介绍:
Ore Geology Reviews aims to familiarize all earth scientists with recent advances in a number of interconnected disciplines related to the study of, and search for, ore deposits. The reviews range from brief to longer contributions, but the journal preferentially publishes manuscripts that fill the niche between the commonly shorter journal articles and the comprehensive book coverages, and thus has a special appeal to many authors and readers.