{"title":"drimane型倍半萜烷作为沉积盆地热效应和地质作用的分子示踪剂","authors":"Biqing Zhu , Quanyou Liu , Huiyuan Xu , Dongya Zhu , Weilong Peng , Xiaoqi Wu , Yongqi Ruan , Chi Zhang","doi":"10.1016/j.chemgeo.2025.122987","DOIUrl":null,"url":null,"abstract":"<div><div>Drimane-type sesquiterpanes exhibit exceptional thermal stability and ubiquity across organic-rich sedimentary systems, from hydrothermal vents to crude oils, positioning them as critical molecular intermediaries in biomarker transformation pathways. The systematic GC–MS analysis of multi-phase crude oils from the Tarim Basin's ultra-deep reservoirs (depth > 7 km, temperature > 140 °C) identifies thermally-controlled molecular transformations. Cheilanthanes, particularly C<sub>19</sub> ∼ C<sub>23</sub> homologues, exhibit greater thermal stability than hopanes. Drimane-type sesquiterpanes display source-dependent initial abundances and maturation-driven transformations: 4,4,8,8,9-pentamethyldecane (RD1) accumulates progressively, 4,4,8,9,9-pentamethyldecane (RD2) shows transient accumulation followed by depletion, while drimane (D) and homodrimane (HD) decline continuously. The transmethylation reaction under high thermal stress leads to RD1 enrichment, making it an ultra-stable end-member in the thermal maturation of C<sub>15</sub> drimane-type sesquiterpanes. Maturity indicators derived from trimethylnaphthalenes and methylphenanthrenes exhibit good correlations with thermal gradient, whereas dibenzothiophene-derived parameters demonstrate the weak correlation. In contrast, sesquiterpane-derived ratios display superior strong correlation with thermal gradient compared to aromatic hydrocarbon indices. The RD1/(RD1 + D + HD) ratio is proposed as an optimized molecular proxy for assessing thermal effects and phase behaviors in sedimentary basins. This study provides a potential tool for investigating the thermal effects of diverse geological processes, such as plate movement, earthquake slip, magmatic intrusion, and hydrothermal activity.</div></div>","PeriodicalId":9847,"journal":{"name":"Chemical Geology","volume":"693 ","pages":"Article 122987"},"PeriodicalIF":3.6000,"publicationDate":"2025-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Drimane-type sesquiterpanes as molecular tracers for thermal effects and geologic processes in sedimentary basins\",\"authors\":\"Biqing Zhu , Quanyou Liu , Huiyuan Xu , Dongya Zhu , Weilong Peng , Xiaoqi Wu , Yongqi Ruan , Chi Zhang\",\"doi\":\"10.1016/j.chemgeo.2025.122987\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><div>Drimane-type sesquiterpanes exhibit exceptional thermal stability and ubiquity across organic-rich sedimentary systems, from hydrothermal vents to crude oils, positioning them as critical molecular intermediaries in biomarker transformation pathways. The systematic GC–MS analysis of multi-phase crude oils from the Tarim Basin's ultra-deep reservoirs (depth > 7 km, temperature > 140 °C) identifies thermally-controlled molecular transformations. Cheilanthanes, particularly C<sub>19</sub> ∼ C<sub>23</sub> homologues, exhibit greater thermal stability than hopanes. Drimane-type sesquiterpanes display source-dependent initial abundances and maturation-driven transformations: 4,4,8,8,9-pentamethyldecane (RD1) accumulates progressively, 4,4,8,9,9-pentamethyldecane (RD2) shows transient accumulation followed by depletion, while drimane (D) and homodrimane (HD) decline continuously. The transmethylation reaction under high thermal stress leads to RD1 enrichment, making it an ultra-stable end-member in the thermal maturation of C<sub>15</sub> drimane-type sesquiterpanes. Maturity indicators derived from trimethylnaphthalenes and methylphenanthrenes exhibit good correlations with thermal gradient, whereas dibenzothiophene-derived parameters demonstrate the weak correlation. In contrast, sesquiterpane-derived ratios display superior strong correlation with thermal gradient compared to aromatic hydrocarbon indices. The RD1/(RD1 + D + HD) ratio is proposed as an optimized molecular proxy for assessing thermal effects and phase behaviors in sedimentary basins. This study provides a potential tool for investigating the thermal effects of diverse geological processes, such as plate movement, earthquake slip, magmatic intrusion, and hydrothermal activity.</div></div>\",\"PeriodicalId\":9847,\"journal\":{\"name\":\"Chemical Geology\",\"volume\":\"693 \",\"pages\":\"Article 122987\"},\"PeriodicalIF\":3.6000,\"publicationDate\":\"2025-07-26\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Chemical Geology\",\"FirstCategoryId\":\"89\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S0009254125003778\",\"RegionNum\":2,\"RegionCategory\":\"地球科学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q1\",\"JCRName\":\"GEOCHEMISTRY & GEOPHYSICS\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Chemical Geology","FirstCategoryId":"89","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0009254125003778","RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"GEOCHEMISTRY & GEOPHYSICS","Score":null,"Total":0}
引用次数: 0
摘要
从热液喷口到原油,drimane型倍半萜烷在富有机质沉积体系中表现出优异的热稳定性和普遍性,使其成为生物标志物转化途径中的关键分子中介。塔里木盆地超深层储层多相原油系统GC-MS分析(深度>;7公里,温度>;140°C)确定热控制分子转化。Cheilanthanes,特别是C19 ~ C23同源物,表现出比藿烷更高的热稳定性。drimane型倍半萜烷表现出源依赖的初始丰度和成熟驱动的转变:4,4,8,8,8,9 -五甲基癸烷(RD1)逐渐积累,4,4,8,9,9-五甲基癸烷(RD2)表现出短暂积累后消耗,而drimane (D)和homdrimane (HD)则持续下降。高热胁迫下的转甲基化反应导致RD1富集,使其成为C15驱动型倍半萜热成熟过程中超稳定的端元。由三甲基萘和甲基菲衍生的成熟度指标与热梯度表现出良好的相关性,而由二苯并噻吩衍生的参数则表现出弱相关性。与芳烃指数相比,倍半萜烷衍生比值与热梯度表现出较强的相关性。提出了RD1/(RD1 + D + HD)比值作为评价沉积盆地热效应和相行为的最佳分子指标。该研究为研究板块运动、地震滑动、岩浆侵入和热液活动等不同地质过程的热效应提供了潜在的工具。
Drimane-type sesquiterpanes as molecular tracers for thermal effects and geologic processes in sedimentary basins
Drimane-type sesquiterpanes exhibit exceptional thermal stability and ubiquity across organic-rich sedimentary systems, from hydrothermal vents to crude oils, positioning them as critical molecular intermediaries in biomarker transformation pathways. The systematic GC–MS analysis of multi-phase crude oils from the Tarim Basin's ultra-deep reservoirs (depth > 7 km, temperature > 140 °C) identifies thermally-controlled molecular transformations. Cheilanthanes, particularly C19 ∼ C23 homologues, exhibit greater thermal stability than hopanes. Drimane-type sesquiterpanes display source-dependent initial abundances and maturation-driven transformations: 4,4,8,8,9-pentamethyldecane (RD1) accumulates progressively, 4,4,8,9,9-pentamethyldecane (RD2) shows transient accumulation followed by depletion, while drimane (D) and homodrimane (HD) decline continuously. The transmethylation reaction under high thermal stress leads to RD1 enrichment, making it an ultra-stable end-member in the thermal maturation of C15 drimane-type sesquiterpanes. Maturity indicators derived from trimethylnaphthalenes and methylphenanthrenes exhibit good correlations with thermal gradient, whereas dibenzothiophene-derived parameters demonstrate the weak correlation. In contrast, sesquiterpane-derived ratios display superior strong correlation with thermal gradient compared to aromatic hydrocarbon indices. The RD1/(RD1 + D + HD) ratio is proposed as an optimized molecular proxy for assessing thermal effects and phase behaviors in sedimentary basins. This study provides a potential tool for investigating the thermal effects of diverse geological processes, such as plate movement, earthquake slip, magmatic intrusion, and hydrothermal activity.
期刊介绍:
Chemical Geology is an international journal that publishes original research papers on isotopic and elemental geochemistry, geochronology and cosmochemistry.
The Journal focuses on chemical processes in igneous, metamorphic, and sedimentary petrology, low- and high-temperature aqueous solutions, biogeochemistry, the environment and cosmochemistry.
Papers that are field, experimentally, or computationally based are appropriate if they are of broad international interest. The Journal generally does not publish papers that are primarily of regional or local interest, or which are primarily focused on remediation and applied geochemistry.
The Journal also welcomes innovative papers dealing with significant analytical advances that are of wide interest in the community and extend significantly beyond the scope of what would be included in the methods section of a standard research paper.