Geochemistry of Crude Oils from Eastern Indonesia1

Peters, K. E.; Fraser, Tom H.; Amris, Welly; Rustanto, Budi; Hermanto, Eddy

doi:10.1306/e4fd4643-1732-11d7-8645000102c1865d

Cited by 48 publications

(10 citation statements)

References 23 publications

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“…9 coals were characterized as low maturity due to the dominance of polar compounds and asphaltenes (Table S5), excessively high Pr/Ph ratio (Table 2), such as AJ02 (4.81), may roughly indicate input of terrestrial higher plant rather than a strong oxidative condition [100]). Pr/nC 17 coupled with Ph/nC 18 can be used for recognizing redox condition, forming environment and type of input materials [101]. Their ratios were distributed in a range of 0.81-3.87 and 0.52-0.91, respectively (Table 2).…”

Section: Sedimentary Environment Favoring Enrichment Of Ga and Inmentioning

confidence: 99%

Enrichment Mechanisms of Gallium and Indium in No. 9 Coals in Anjialing Mine, Ningwu Coalfield, North China, with a Preliminary Discussion on Their Potential Health Risks

Zhang

Hao

Tian³

et al. 2021

Minerals

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To provide a comprehensive insight into the enrichment mechanism of gallium and indium in No. 9 coals, eighteen samples were collected from Anjialing mine, Ningwu Coalfield, Shanxi Province for coal petrological, mineralogical and geochemical analyses. The results suggested that Ga and In enrichment mainly hosted in the top horizons, with average concentration coefficients of 8.99 and 2.73 respectively, compared with the rest of horizons (2.46 for Ga and 1.69 for In). Source apportionment indicated that Ga and In were mainly derived from bauxite of Benxi Formation in Yinshan Oldland, while In could originate from felsic magmatic rocks in Yinshan Oldland as well. In addition, weak oxidation condition, medium to intensive weathering, transgression and input of terrestrial higher plants had positive effects on Ga and In enrichment. With the rapid expansion of emerging electronics manufacturing, Ga and In, of which potential risks on human health were neglected previously, were recently considered as hazardous elements. Therefore, this paper also discussed the potential pathways that these elements threatened human health. We suggested that potential risks on environment and human health caused by Ga and In enrichment in coals and coal-related products should be taken into account besides their economic value.

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Section: Sedimentary Environment Favoring Enrichment Of Ga and Inmentioning

confidence: 99%

Enrichment Mechanisms of Gallium and Indium in No. 9 Coals in Anjialing Mine, Ningwu Coalfield, North China, with a Preliminary Discussion on Their Potential Health Risks

Zhang

Hao

Tian³

et al. 2021

Minerals

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“…A significantly well-preserved organic matter transforming into the peat layers is evident from the high CPI values indicating limited microbial breakdown and diagenetic alterations (Alexander et al, 1981;Marzi et al, 1993;Peters et al, 2005). Further, low degree of biodegradation and relatively mild diagenesis are confirmed by the relation between Pr/n-C 17 and Ph/n-C 18 (Peters et al, 1999) (Figure 7) and presence of the unsaturated hopanes such as 22, 29, 30-trisnorhop-17(21)-ene (Te), and hop-22(29)-ene (diploptene). With increasing microbial degradation, values for the ratios Pr/n-C 17 and Ph/ n-C 18 increase (>1) since normal alkanes are consumed faster than acyclic terpenoids.…”

Section: Depositional Condition Of the Environmentmentioning

confidence: 86%

Vegetation History in a Peat Succession Over the Past 8,000 years in the ISM-Controlled Kedarnath Region, Garhwal Himalaya: Reconstruction Using Molecular Fossils

et al. 2021

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The Holocene epoch has witnessed several natural climate variations and these are well encoded in various geological archives. The present biomarker investigation in conjunction with previously published multi-proxy records was applied to reconstruct organic matter (OM) sources forming the peat succession spanning the last 8000 cal yr BP and shift in hydrological conditions from the Kedarnath region, Garhwal Himalaya. Intensified monsoon prevailed from ∼7515 until ∼2300 cal yr BP but with reversal to transient arid period particularly between ∼5200 and ∼3600 cal yr BP as revealed by the variability in n-C23/n-C31, ACL (average chain length of n-alkanes) and Paq (P-aqueous) values. A prolonged arid phase is recognizable during the interval between ∼2200 and ∼370 cal yr BP suggested by the n-alkane proxies. Regional scale heterogeneity in the monsoonal pattern is known in the studied temporal range of mid to late Holocene across the Indian subcontinent that is probably a result of complex climate dynamics, sensitivity of proxies and impact of teleconnections. The biomarker signatures deduced from gas chromatography mass spectrometry (GCMS) analysis are suggestive of a mixed biotic input that includes prokaryotes, Sphagnum spp. and gymnosperm flora. The mid chain alkanes viz. n-C23 and n-C25 denote the presence of typical peat forming Sphagnum moss that preferentially grows in humid and waterlogged conditions. Diterpane marker such as ent-kaurane indicates contribution of gymnosperms, whereas the hopanes are signatures of microbial input. The preservation of organic matter is attributed to little microbial degradation in a largely suboxic depositional environment. Our study strengthens the applicability of organic geochemical proxies for the reconstruction of past climate history and indicates their suitability for use on longer timescales given the high preservation potential of the molecular remains.

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“…However, the ratios of the upper member are slightly higher, revealing an anoxic to suboxic environment. Plots of Pr/n-C 17 versus Ph/n-C 18 can also be used to infer the redox conditions of source rocks [92], in this case indicating a weakly oxidizing to weakly reducing depositional environment with mixed organic inputs (Figure 10d).…”

Section: Redox Conditionsmentioning

confidence: 99%

Permian Cyanobacterial Blooms Resulted in Enrichment of Organic Matter in the Lucaogou Formation in the Junggar Basin, NW China

et al. 2023

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The Permian Lucaogou Formation in the Junggar Basin, NW China is the target layer for shale oil exploration, but its hydrocarbon precursors have remained the focus of debate. In this study, we investigated the Lucaogou source rocks throughout Well J10025 by conducting detailed petrological, paleontological, and geochemical analyses for the purpose of revealing the occurrence of cyanobacterial blooms as specific hydrocarbon events in the upper Lucaogou Formation. The morphological characteristics of the microfossils and the geochemical signatures of the microfossil-bearing layers support a biological affinity with Microcystis, a kind of cyanobacteria. Microcystis observed as colonial forms embedded in the upper Lucaogou Formation are of great abundance, indicating the presence of cyanobacterial blooms. They were further evidenced by cyanobacteria-derived biomarkers including low terrestrial/aquatic ratio, high 2α-methylhopane index values, and high abundance of 7- and 8-monomethyl heptadecanes. The blooms occurred in a semiarid and brackish paleoenvironment with anoxic to suboxic water conditions and intermittent volcanic eruptions. Permian Microcystis blooms contributed to the enrichment of organic matter in the upper Lucaogou Formation in two main ways: by directly promoting the accumulation of algal biomass and by creating an oxygen-depleted environment for better preservation of organic matter. This study adds a new record to the geological occurrences of cyanobacterial blooms in the Permian, and provides unique insight into the hydrocarbon generation of Jimsar shale oil in the Junggar Basin.

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Geochemistry of Crude Oils from Eastern Indonesia1

Cited by 48 publications

References 23 publications

Enrichment Mechanisms of Gallium and Indium in No. 9 Coals in Anjialing Mine, Ningwu Coalfield, North China, with a Preliminary Discussion on Their Potential Health Risks

Enrichment Mechanisms of Gallium and Indium in No. 9 Coals in Anjialing Mine, Ningwu Coalfield, North China, with a Preliminary Discussion on Their Potential Health Risks

Vegetation History in a Peat Succession Over the Past 8,000 years in the ISM-Controlled Kedarnath Region, Garhwal Himalaya: Reconstruction Using Molecular Fossils

Permian Cyanobacterial Blooms Resulted in Enrichment of Organic Matter in the Lucaogou Formation in the Junggar Basin, NW China

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