title: Thermal and spectral characterization of anaerobic thermal behavior patterns in a lacustrine sediment core.
abstract: The thermal evolution of sedimentary organic matter is a significant mechanism in continental oil and gas formation. This study presents a new method to estimate vertical thermal evolution trends in a lake sediment core. Twenty sediment samples from a 60-cm core recovered from Lake Bosten were heated to 600 °C at a rate of 10 °C min(-1) under a N2 atmosphere. The sediments were characterized by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA), and then, the samples were analyzed with total organic carbon (TOC) analyses, X-ray diffraction, and (137)Cs isotopic dating techniques. Two main anaerobic thermal degradation processes were observed in the thermograms. The pyrolysis results showed variations with sediment age, with labile carbon (237.2 ± 42.98 °C) manifesting different thermogram patterns than recalcitrant carbon (498.35 ± 30.09 °C). There was a significant linear correlation between sample weight loss and TOC (r = 0.972, p < 0.001), as well as between the DSC and TGA peaks (r = 0.963, p < 0.001). As a conclusion, the thermal stability of both labile organic carbon and recalcitrant organic carbon in lacustrine sediment core increased gradually with age. These results confirm that advanced thermal techniques (DSC and TGA) operated in inert gas are potential quantitative methods to characterize the anaerobic thermal behavior of sediment organic carbon.
authors.affiliation: Department of Chemistry, University of Science and Technology of China, Hefei, Anhui, China.|State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing, 100012, China.
authors.forename: Fei
authors.initials: F
authors.lastname: Guo
authors.affiliation: State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing, 100012, China.
authors.forename: Yunsong
authors.initials: Y
authors.lastname: Mu
authors.affiliation: Guizhou University of Finance and Economics, Guiyang, Guizhou, China.
authors.forename: Cheng
authors.initials: C
authors.lastname: Chen
authors.affiliation: State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing, 100012, China.
authors.forename: Haiqing
authors.initials: H
authors.lastname: Liao
authors.affiliation: State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing, 100012, China. baiyc@craes.org.cn.
authors.forename: Yingchen
authors.initials: Y
authors.lastname: Bai
mesh_terms: D002244:Carbon / Q000032:analysis / Q000737:chemistry; D002623:Chemistry Techniques, Analytical; D019015:Geologic Sediments / Q000032:analysis / Q000737:chemistry; D006358:Hot Temperature; D060106:Lakes / Q000032:analysis / Q000737:chemistry; D061329:Oil and Gas Fields / Q000737:chemistry*
chemical_list: D002244:Carbon
keywords: 137Cs isotopic dating techniques; Anaerobic thermal behavior; Derivative thermogravimetric analysis; Differential scanning calorimetry; Lacustrine sediment core; Sediment organic matter