Geochemical evolution of ore-forming fluids and key controlling factors in super-large gold deposits: A case study of the North Sanshandao gold deposit, Jiaodong Peninsula, Eastern China

IF 3.6 2区地球科学 Q1 GEOLOGY

Ore Geology Reviews Pub Date : 2025-08-13 DOI:10.1016/j.oregeorev.2025.106831

Jian Li , Ming-chun Song , Da-peng Li , Zeng-sheng Li , Wen-yan Cai , Xue-feng Yu , Zhong-hua Tian , Nai-jie Chi , Qing-yi Cui , Ming Lei

{"title":"Geochemical evolution of ore-forming fluids and key controlling factors in super-large gold deposits: A case study of the North Sanshandao gold deposit, Jiaodong Peninsula, Eastern China","authors":"Jian Li , Ming-chun Song , Da-peng Li , Zeng-sheng Li , Wen-yan Cai , Xue-feng Yu , Zhong-hua Tian , Nai-jie Chi , Qing-yi Cui , Ming Lei","doi":"10.1016/j.oregeorev.2025.106831","DOIUrl":null,"url":null,"abstract":"<div><div>Precise characterization of ore-forming fluid evolution is crucial for understanding the mineralization mechanisms of large-scale gold deposits. The North Sanshandao gold deposit, China’s first offshore super-large gold resource (>562 t Au @ 4.35 g/t), serves as an exemplary case study for deciphering the formation processes of both super-large and Jiaodong-type gold deposits. Petrographic observations and crosscutting relationships define four distinct mineralization stages. Fluid inclusion (FI) studies reveal four FI types in quartz across these stages: (i) liquid (H<sub>2</sub>O)-dominated two-phase (type 1), (ii) vapor (H<sub>2</sub>O)-dominated two-phase (type 2), and (iii) CO<sub>2</sub>-bearing (liquid and vapor) inclusions (types 3a and 3b). Stage I (254–375 °C, 3.53–10.74 wt% NaCl eq.) contains all four FI types, whereas stage II (195–313 °C, 2.06–10.37 wt% NaCl eq.) is marked by types 1, 2, and 3a. Stage III (196–336 °C, 5.05–9.47 wt% NaCl eq.) exhibits only types 1 and 3a. Notably, stages I–III display clear evidence of fluid immiscibility, indicative of a low-salinity, medium-temperature NaCl–H<sub>2</sub>O–CO<sub>2</sub> hydrothermal system. In contrast, stage IV (134–184 °C, 3.53–9.34 wt% NaCl eq.) transitions to a simpler NaCl–H<sub>2</sub>O system, with only type 1 inclusions present.</div><div>Stable isotope analysis reveals that the δ<sup>18</sup>O<sub>H2O</sub> (5.7–10.0 ‰) and δD (90.9–78.4 ‰) values indicate a predominantly magmatic fluid source. However, stage IV records a significant influx of meteoric water (δ<sup>18</sup>O<sub>H2O</sub> = − 9.4 ‰, δD = − 100.5 ‰). Pressure estimates for stages I–III range from 54.2–81.0 MPa (avg. 69.3 MPa; ∼5.5–8.3 km depth), 42.8–90.9 MPa (avg. 63.1 MPa; ∼4.4–9.3 km depth), and 54.7–87.6 MPa (avg. 60.9 MPa; ∼5.6–8.9 km depth), respectively. Pyrite noble gas isotopes provide further insights: <sup>3</sup>He/<sup>4</sup>He ratios in auriferous pyrite from stages II and III range from 1.37 to 1.44 Ra (25–26 % mantle-derived He) and 0.07–1.29 Ra (1–23 % mantle-derived He), respectively, highlighting the mantle-derived fluids contribution to mineralization. Combined H-O-He-Ar isotopic data strongly support a unified magmatic origin for the ore-forming fluids across the Jiaodong gold deposits.</div></div>","PeriodicalId":19644,"journal":{"name":"Ore Geology Reviews","volume":"186 ","pages":"Article 106831"},"PeriodicalIF":3.6000,"publicationDate":"2025-08-13","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/S0169136825003919","RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"GEOLOGY","Score":null,"Total":0}

引用次数: 0

Abstract

Precise characterization of ore-forming fluid evolution is crucial for understanding the mineralization mechanisms of large-scale gold deposits. The North Sanshandao gold deposit, China’s first offshore super-large gold resource (>562 t Au @ 4.35 g/t), serves as an exemplary case study for deciphering the formation processes of both super-large and Jiaodong-type gold deposits. Petrographic observations and crosscutting relationships define four distinct mineralization stages. Fluid inclusion (FI) studies reveal four FI types in quartz across these stages: (i) liquid (H₂O)-dominated two-phase (type 1), (ii) vapor (H₂O)-dominated two-phase (type 2), and (iii) CO₂-bearing (liquid and vapor) inclusions (types 3a and 3b). Stage I (254–375 °C, 3.53–10.74 wt% NaCl eq.) contains all four FI types, whereas stage II (195–313 °C, 2.06–10.37 wt% NaCl eq.) is marked by types 1, 2, and 3a. Stage III (196–336 °C, 5.05–9.47 wt% NaCl eq.) exhibits only types 1 and 3a. Notably, stages I–III display clear evidence of fluid immiscibility, indicative of a low-salinity, medium-temperature NaCl–H₂O–CO₂ hydrothermal system. In contrast, stage IV (134–184 °C, 3.53–9.34 wt% NaCl eq.) transitions to a simpler NaCl–H₂O system, with only type 1 inclusions present.

Stable isotope analysis reveals that the δ¹⁸O_H2O (5.7–10.0 ‰) and δD (90.9–78.4 ‰) values indicate a predominantly magmatic fluid source. However, stage IV records a significant influx of meteoric water (δ¹⁸O_H2O = − 9.4 ‰, δD = − 100.5 ‰). Pressure estimates for stages I–III range from 54.2–81.0 MPa (avg. 69.3 MPa; ∼5.5–8.3 km depth), 42.8–90.9 MPa (avg. 63.1 MPa; ∼4.4–9.3 km depth), and 54.7–87.6 MPa (avg. 60.9 MPa; ∼5.6–8.9 km depth), respectively. Pyrite noble gas isotopes provide further insights: ³He/⁴He ratios in auriferous pyrite from stages II and III range from 1.37 to 1.44 Ra (25–26 % mantle-derived He) and 0.07–1.29 Ra (1–23 % mantle-derived He), respectively, highlighting the mantle-derived fluids contribution to mineralization. Combined H-O-He-Ar isotopic data strongly support a unified magmatic origin for the ore-forming fluids across the Jiaodong gold deposits.

Abstract Image

查看原文本刊更多论文

超大型金矿床成矿流体地球化学演化及主控因素——以胶东半岛北三山岛金矿床为例

成矿流体演化的精确表征对于认识大型金矿床的成矿机制至关重要。北三山岛金矿床是中国首个海上超大型金矿资源（>562 t Au @ 4.35 g/t），对破解超大型金矿床和胶东型金矿床的形成过程具有示范意义。岩石学观察和横切关系确定了四个不同的成矿阶段。流体包裹体（FI）研究揭示了石英在这些阶段中的四种FI类型：(i)以液体（H2O）为主的两相（类型1），（ii）以蒸汽（H2O）为主的两相（类型2），以及（iii）含二氧化碳（液体和蒸汽）包裹体（类型3a和3b）。阶段I（254-375°C, 3.53-10.74 wt% NaCl eq.）包含所有四种FI类型，而阶段II（195-313°C, 2.06-10.37 wt% NaCl eq.）由类型1、2和3a标记。阶段III（196-336°C, 5.05-9.47 wt% NaCl eq.）仅显示类型1和3a。值得注意的是，第1 - 3阶段显示出明显的流体不混相，表明存在低盐度、中温的NaCl-H2O-CO2热液系统。相比之下，阶段IV（134-184°C, 3.53-9.34 wt% NaCl当量）转变为更简单的NaCl - h2o体系，只存在1型包裹体。稳定同位素分析表明，δ18OH2O（5.7 ~ 10.0‰）和δD（90.9 ~ 78.4‰）值显示岩浆流体来源为主。第四阶段有大量的大气水流入（δ18OH2O = - 9.4‰，δD = - 100.5‰）。I-III阶段的压力估计范围分别为54.2-81.0 MPa（平均69.3 MPa; ~ 5.5-8.3 km深度）、42.8-90.9 MPa（平均63.1 MPa; ~ 4.4-9.3 km深度）和54.7-87.6 MPa（平均60.9 MPa; ~ 5.6-8.9 km深度）。黄铁矿稀有气体同位素提供了进一步的信息：II期和III期含金黄铁矿的3He/4He比值分别为1.37 ~ 1.44 Ra（25 ~ 26%幔源He）和0.07 ~ 1.29 Ra(1 ~ 23%幔源He)，突出了幔源流体对成矿作用的贡献。综合H-O-He-Ar同位素资料有力地支持胶东金矿床成矿流体的统一岩浆成因。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

求助全文

约1分钟内获得全文求助全文

来源期刊

Ore Geology Reviews 地学-地质学

CiteScore

6.50

自引率

27.30%

发文量

546

审稿时长

22.9 weeks

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.