Implications of solid bitumen association with low- to medium-temperature hydrothermal minerals in hydrocarbon reservoirs of Southwest China: Insights from organic petrology and sulfur isotopes

被引：0

作者：

Sun, Wen ^{[1
,2
]}

Zhong, Ningning ^{[1
,2
]}

Lu, Yongli ^{[2
]}

Li, Dahua ^{[3
]}

Luo, Qingyong ^{[2
]}

Yao, Lipeng ^{[4
]}

Yang, Yanan ^{[2
]}

Cai, Chunfang ^{[2
]}

Fang, Zilong ^{[2
]}

机构：

[1] China Univ Petr, Key Lab Shale Gas Explorat, Minist Nat Resources, Beijing 102249, Peoples R China

[2] China Univ Petr, Coll Geosci, Beijing 102249, Peoples R China

[3] Chongqing Inst Geol & Mineral Resources, Key Lab Shale Gas Explorat, Minist Nat Resources, Chongqing 401120, Peoples R China

[4] Nanning Normal Univ, Key Lab Environm Change & Resources Use Beibu Gulf, Minist Educ, Nanning 530001, Peoples R China

来源：

INTERNATIONAL JOURNAL OF COAL GEOLOGY | 2025年 / 303卷

基金：

中国国家自然科学基金;

关键词：

Solid bitumen; Metal sulfide minerals; Sulfur isotopes; Organic-inorganic interactions; Metallogeny; Paleo-oil reservoir reconstruction; Southwest China; THERMOCHEMICAL SULFATE REDUCTION; PB-ZN DEPOSIT; GOLD DEPOSITS; SICHUAN BASIN; SULFIDE; GENESIS; BACTERIAL; AGE; MINERALIZATION; DISTRICT;

D O I：

10.1016/j.coal.2025.104739

中图分类号：

TE [石油、天然气工业]; TK [能源与动力工程];

学科分类号：

0807 ; 0820 ;

摘要：

Solid bitumen in Southwest China often coexists with metal deposits, indicating a genetic link between organic matter and ore formation. However, this linkage remains underexplored. This study investigated the relationship between sulfur origin and organic matter maturity through sulfur isotopes of metal sulfides. Organic petrology revealed that solid bitumen associated with minerals exhibited stronger optical anisotropy (Delta BRo >3.32 %) and higher S/C atomic ratios (0.029-0.033) than non-associated bitumen (0.005-0.021). Fluid inclusion analysis showed that ore-stage calcite inclusions have higher homogenization temperatures than those in paleo-oil reservoirs, indicating that ore-forming processes accelerated hydrocarbon thermal evolution. Solid bitumen-mineral associations were classified into Mississippi Valley-type (MVT), stratiform mercury, and disseminated gold deposits. Sulfur isotope compositions identified three sulfur sources: bacterial sulfate reduction (BSR), thermochemical sulfate reduction (TSR), and thermal decomposition of sulfur-containing organic matter (TDS). In the Lanping-Simao Basin, delta S-34(CDT) values below 0 parts per thousand suggest sulfur derived from BSR, with hydrocarbons contributing reduced sulfur. In the Xuefeng Mountains Uplift, delta S-34(CDT) values exceeding 20 parts per thousand indicate TSR-driven sulfur, with metallogeny enhancing hydrocarbon accumulation and mineralization. In the Kangdian Axis, delta S-34(CDT) values under 20 parts per thousand suggest sulfur from TSR and TDS, with mineralization causing oil cracking and reservoir destruction. The findings demonstrate that metallogeny accelerates organic matter maturation, reshapes reservoirs, and drives oil cracking. Simultaneously, organic-inorganic interactions govern metal sulfide formation and precipitation, underscoring their critical role in ore genesis.

引用

页数：18