Origin, Distribution and Geochemical Significance of Isopropyltoluene Isomers in Crude Oil

来源 :地球科学学刊(英文版) | 被引量 : 0次 | 上传用户:goodcat13579
下载到本地 , 更方便阅读
声明 : 本文档内容版权归属内容提供方 , 如果您对本文有版权争议 , 可与客服联系进行内容授权或下架
论文部分内容阅读
With comprehensive two-dimensional gas chromatography linked to time-of-flight mass spectrometry (GC × GC-TOFMS), ten light hydrocarbon (LH) compounds were qualitatively and quantitatively studied in light hydrocarbons (LHs) components of crude oils. For significant differences in the concentrations of 3-isoproyltoluene (3-iPT), 4-isoproyltoluene (4-iPT) and 2-isoproyltoluene (2-iPT) in crude oils, and the 2-iPT probably derived mainly from similar skeleton monocyclic terpenoids via de- hydrogenation and aromatization, the ratios of (3+4)-/2-iPT (iPTr), 3-/2-iPT (iPTr1) and 4-/2-iPT (iPTr2) are proposed to distinguish the organic matter origin of crude oils. Relatively higher iPTr (>8.0), iPTr1 (>7.0) and iPTr2 (>4.0) values indicate that crude oils are sourced from the co-contribution of lower aquatic organisms, bacteria, algae, and terrestrial higher plants, whereas lower iPTr (<5.0), iPTr1 (<3.0), iPTr2 (<2.0) values suggest that crude oils originated from terrestrial higher plants. The iPTr, iPTr1, and iPTr2 values show notable distinction which is mainly controlled by 2-iPT concentrations, while the concentrations of 3-iPT and 4-iPT have similar distribution range in all studied oils. The 2-iPT depleted in marine oils from the Tarim Basin and lacustrine oils from the Beibuwan Basin is less than 0.30 mg/g LHs, whereas 2-iPT enriched in swamp oils from the Tarim Basin is greater than 0.50 mg/g LHs. The iPTr, iPTr1, and iPTr2 ratios and 2-iPT concentrations can be used to distinguish the organic matter origin of crude oils, especially for light oils and condensates with low concentrations of biomarkers.
其他文献
The geochemical cycling of copper in the hydrosphere and soil environments primarily involves the transport of Cu from rocks to rivers via weathering. Understanding the factors controlling Cu isotope fractionation during weathering is crucial for the purp
The rate of net primary production in the Proterozoic ocean was suggested to be no more than 10%of its modern value (Laakso and Schrag, 2019), however, in the Mesoproterozoic Xiamaling Formation, the export production values could reach 20%-150%of the pre
The Niangzhong diabase dikes, dated at 138.1 ± 0.4 Ma, are located within the outcrop area of the Comei large igneous province (LIP). These diabase samples can be divided into two groups:samples in Group 1 show varying MgO (1.50 wt.%-10.25 wt.%) and TiO2
The loess depositions in Shandong Province are important parts of loess records in east- ern China, but their origin and genetic linkage between the Yellow River and the Chinese Loess Plateau are still unclear. This paper presents the detrital-zircon evid
Emeishan large igneous province (ELIP), one of the largest continental volcanic provinc-es worldwide (e. g., Karoo), is extensively distributed along the western margin of the Yangtze Block. Even though the consensus that the ELIP is of a plume-related or
It has been suggested that the carbonated mantle reflected by Mg-Zn isotopic anomalies of Cenozoic intraplate basalts from East Asia coincides with the stagnant West Pacific slab in the man- tle transition zone. However, the northern boundary of such carb
A preliminary survey of silver isotopic composition in four polymetallic ores in eastern China shows a larger variation in δ109Ag from-0.014‰to+0.983‰, which is within the total ranges for the entire respective ore deposit types worldwide. The diversity o
The Huayangchuan ore belt is located in the western segment of Xiaoqinling Orogen in the southern margin of the North China Craton (NCC), and hosts voluminous magmatism and signifi- cant U-REE-Mo-Cu-Fe polymetallic mineralization. However, geochronologica
Many studies focus on mineralization of huge magnetite ore deposits and petrogenesis of their large-volume host rocks. However, magma generation of those small-scale intrusions with enrich- ment of magnetite is poorly reported and paid attention to. We he
We present detailed geochronological, geochemical, and zircon Hf isotopic data for Late Paleozoic granitic rocks from Handagai and Zhonghe plutons in the Xing\'an Block, NE China, aiming to provide constraints on their origin and tectonic implications.