Organic Petrology and Geochemistry: Exploring the Organic-Rich Facies

A special issue of Minerals (ISSN 2075-163X). This special issue belongs to the section "Mineral Geochemistry and Geochronology".

Deadline for manuscript submissions: 30 January 2026 | Viewed by 2156

Special Issue Editors


E-Mail Website
Guest Editor
1. LAFO—Laboratório de Palinofácies & Fácies Orgânica, Departamento de Geologia, Instituto de Geociências, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
2. Institute of Earth Sciences—Porto Pole, Faculdade de Ciências, Universidade do Porto, Porto, Portugal
Interests: organic petrology; palynofacies; kerogen; maceral; solid bitumen; depositional paleoenvironment; organic geochemistry; organic facies
Special Issues, Collections and Topics in MDPI journals

E-Mail Website
Guest Editor
British Geological Survey, Nottingham, UK
Interests: depositional environment; thermal maturity; gas sorption; porosity; permeability; rock mechanics

Special Issue Information

Dear Colleagues,

A multidisciplinary approach, incorporating organic petrology and geochemistry (both organic and inorganic), provides fundamental insights into the characterization of organic-rich facies in sedimentary basins. The lateral and vertical distribution of these facies is influenced by depositional environmental features, including primary productivity, organic matter input, water column redox conditions, and sediment accumulation rates. By examining various organic and inorganic facies across different basins and integrating petrological and geochemical data, a more comprehensive understanding of the diagenetic processes affecting organic matter can be achieved. This approach facilitates the identification of key factors controlling the preservation and alteration of organic matter, with particular emphasis on kerogen types and their transformation pathways. Such insights provide new perspectives on interpretating the characteristics and potential of hydrocarbon reservoirs. Understanding the organic facies of source rocks is also crucial as the world shifts its focus on "advantaged hydrocarbons" in the context of the energy transition.

This Special Issue will explore the intricate relationships between organic matter types, depositional environments, thermal maturity, and the interplay between organic and inorganic components within organic-rich facies in sedimentary basins. We invite contributions that adopt a multidisciplinary approach and a broad spectrum of techniques for analyzing organic matter, both petrographic and geochemical. Studies that investigate the relationships between organic and inorganic matter are welcomed, as they provide valuable insights into the complex processes governing the evolution of sedimentary basins.

We thank you and look forward to receiving your contributions.

Dr. Paula Alexandra Gonçalves
Dr. Qian Zhang
Guest Editors

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Minerals is an international peer-reviewed open access monthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2400 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

  • organic-rich facies
  • organic petrology
  • organic geochemistry
  • inorganic geochemistry
  • palynofacies
  • biomarkers
  • scanning electron microscopy
  • stable isotope geochemistry
  • kerogen
  • thermal maturation
  • depositional paleoenvironment
  • basin analysis

Benefits of Publishing in a Special Issue

  • Ease of navigation: Grouping papers by topic helps scholars navigate broad scope journals more efficiently.
  • Greater discoverability: Special Issues support the reach and impact of scientific research. Articles in Special Issues are more discoverable and cited more frequently.
  • Expansion of research network: Special Issues facilitate connections among authors, fostering scientific collaborations.
  • External promotion: Articles in Special Issues are often promoted through the journal's social media, increasing their visibility.
  • Reprint: MDPI Books provides the opportunity to republish successful Special Issues in book format, both online and in print.

Further information on MDPI's Special Issue policies can be found here.

Published Papers (4 papers)

Order results
Result details
Select all
Export citation of selected articles as:

Research

21 pages, 5880 KB  
Article
Petrographic and Geochemical Insights from Fibrous Calcite Veins: Unraveling Overpressure and Fracture Evolution in the Upper Permian Dalong Formation, South China
by An Liu, Lin Chen, Shu Jiang, Hai Li, Baomin Zhang, Yingxiong Cai, Jingyu Zhang, Wei Wei and Feiyong Xia
Minerals 2025, 15(9), 896; https://doi.org/10.3390/min15090896 - 24 Aug 2025
Viewed by 346
Abstract
The characteristics and evolution of fibrous calcite veins in organic-rich shales have gained significant attention due to the recent advancements in shale oil and gas exploration. However, the fibrous calcite veins in the Upper Permian Dalong Formation remain lacking in awareness. To investigate [...] Read more.
The characteristics and evolution of fibrous calcite veins in organic-rich shales have gained significant attention due to the recent advancements in shale oil and gas exploration. However, the fibrous calcite veins in the Upper Permian Dalong Formation remain lacking in awareness. To investigate the formation and significance of bedding-parallel fibrous calcite veins in the Dalong Formation, we conducted an extensive study utilizing petrography, geochemistry, isotopic analysis, and fluid inclusion studies on outcrops of the Dalong Formation in South China. Our findings reveal that fibrous calcite veins predominantly develop in the middle section of the Dalong Formation, specifically within the transitional interval between siliceous and calcareous shales, characterized by symmetric, antitaxial fibrous calcite veins. The δ13C values of these veins exhibit a broad range (−4.53‰ to +3.39‰) and display a decreasing trend in the directions of fiber growth from the central part, indicating an increased contribution of organic carbon to the calcite veins. Additionally, a consistent increase in trace element concentrations from the central part toward the fiber growth directions suggests a singular fluid source in a relatively closed environment, while other samples exhibit no distinct pattern, possibly due to the mixing of fluids from multiple layers resulting from repeated opening and closing of bedding-parallel fractures in the shales. The notable difference in δEu between the fibers on either side of the median zone indicates that previously formed veins acted as barriers, impeding the mixing of fluids, with the variation in δEu reflecting the differing sedimentary properties of the surrounding rocks. The in situ U-Pb dating of fibrous calcite veins yields an absolute age of 211 ± 23 Ma, signifying formation during the Late Triassic, which correlates with a shale maturity of 1.0‰ to 1.25‰. This integrated study suggests that the geochemical records of fibrous calcite veins document the processes related to overpressure generation and the opening and healing of bedding-parallel fractures within the Dalong Formation. Full article
(This article belongs to the Special Issue Organic Petrology and Geochemistry: Exploring the Organic-Rich Facies)
Show Figures

Figure 1

24 pages, 9320 KB  
Article
Permian Longtan Shale in Guizhou, China: From Mineralogy and Geochemistry to Paleoenvironments
by Ende Deng, Jinchuan Zhang, Qian Zhang, Zaigang Xu, Pingping Ye, Zhihua Yan and Bingren Jiang
Minerals 2025, 15(8), 850; https://doi.org/10.3390/min15080850 - 10 Aug 2025
Viewed by 393
Abstract
The depositional environment of the Permian Longtan shale (LS) in southwestern Guizhou Province, China, has been analyzed using mineralogical and geochemical approaches. Macroscopic observations of those studied LS samples showed that the LS is rather homogeneous and interbedded with coal strips, suggesting a [...] Read more.
The depositional environment of the Permian Longtan shale (LS) in southwestern Guizhou Province, China, has been analyzed using mineralogical and geochemical approaches. Macroscopic observations of those studied LS samples showed that the LS is rather homogeneous and interbedded with coal strips, suggesting a relatively stable and shallow water environment. A detailed microscopic analysis demonstrated that higher land plants contributed the predominant proportion of organic matter in the LS. Inorganic geochemical analysis revealed a mixed source of materials with relatively larger proportions of basalt and andesite. Semiarid to humid and warm climates corresponding to an overall intensive weathering were deduced in the late Permian periods. The LS was deposited in a brackish-to-marine water environment with an oxic to dysoxic redox condition. Sea level rise/down coupled with changes in climate, water salinity, and redox condition jointly controlled the formation of the Longtan shale. Mineralogical composition indicates that the LS mainly comprises of argillaceous with minor siliceous facies, which will likely bring challenges for hydraulic fracturing. Full article
(This article belongs to the Special Issue Organic Petrology and Geochemistry: Exploring the Organic-Rich Facies)
Show Figures

Figure 1

31 pages, 29045 KB  
Article
Earliest Cambrian Carbonate Platform Evolution, Environmental Change, and Organic Matter Accumulation in the Northwestern Yangtze Block, South China
by Jincheng Liu, Qingchun Jiang, Yan Zhang, Jingjiang Liu, Yifei Ai, Pengzhen Duan and Guangyou Zhu
Minerals 2025, 15(8), 812; https://doi.org/10.3390/min15080812 - 31 Jul 2025
Viewed by 351
Abstract
The earliest Cambrian (ca., 538.8–524.8 Ma) was an important period in geological history witnessing significant environmental change, during which organic-rich facies were developed in the Yangtze Platform, South China. However, the contemporaneous paleogeographic and stratigraphic framework within which the environmental change and organic [...] Read more.
The earliest Cambrian (ca., 538.8–524.8 Ma) was an important period in geological history witnessing significant environmental change, during which organic-rich facies were developed in the Yangtze Platform, South China. However, the contemporaneous paleogeographic and stratigraphic framework within which the environmental change and organic matter accumulation took place remains poorly understood. We investigate this based on facies, sequence stratigraphic, and geochemical analyses of the lowermost Cambrian Maidiping and Zhujiaqing formations in the northwestern Yangtze Block. The results show that the terminal Ediacaran rimmed platform changed into a foredeep carbonate ramp and backbulge basin after the onset of the earliest Cambrian transgression. Across the Ediacaran–Cambrian boundary, the shallow-marine redox condition rapidly transitioned from relative euxinia to an oxygen-rich state. During the late transgression to highstand normal regression, the foredeep carbonate ramp expanded to the cratonic interior, and nutrients brought by intensified continental weathering and upwelling promoted significant phytoplankton proliferation, an increase in oxygen level and primary productivity, and then organic matter enrichment. During the forced regression, the carbonate ramp gradually changed into a rimmed platform. The weakening continental weathering and expanding anoxic area during the forced to lowstand normal regression led to the significant organic carbon burial in the foredeep basin. Full article
(This article belongs to the Special Issue Organic Petrology and Geochemistry: Exploring the Organic-Rich Facies)
Show Figures

Figure 1

20 pages, 7195 KB  
Article
Bitumen Characteristics, Genesis, and Hydrocarbon Significance in Paleozoic Reservoirs: A Case Study in the Kongxi Slope Zone, Dagang Oilfield, Huanghua Depression
by Da Lou, Yingchang Cao and Xueyu Han
Minerals 2025, 15(5), 443; https://doi.org/10.3390/min15050443 - 25 Apr 2025
Viewed by 311
Abstract
The Paleozoic strata in the Kongxi slope zone of the Dagang oilfield, Huanghua depression, exhibit significant hydrocarbon exploration potential. Although bitumen is widely present in the Paleozoic reservoirs, its formation process and genetic mechanism remain poorly understood. This study systematically investigates the occurrence, [...] Read more.
The Paleozoic strata in the Kongxi slope zone of the Dagang oilfield, Huanghua depression, exhibit significant hydrocarbon exploration potential. Although bitumen is widely present in the Paleozoic reservoirs, its formation process and genetic mechanism remain poorly understood. This study systematically investigates the occurrence, maturity, origin, and evolutionary processes of Paleozoic reservoir bitumen in the Kongxi zone through core observations, microscopic analyses, geochemical testing, and thermal simulation experiments. The results reveal that reservoir bitumen in the Kongxi slope zone is characteristically black with medium to medium-high maturity. In core samples, bitumen occurs as bands, veins, lines, and dispersions within partially filled fractures and breccia pores. Petrographic analysis shows bitumen partially occupying intergranular pores and intergranular pores of Lower Paleozoic carbonate rocks and Upper Paleozoic sandstones, either as complete or partial pore fills. Additional bitumen occurrences include strip-like deposits along microfractures and as bitumen inclusions. Dark brown bitumen fractions were also identified in crude oil separates. The formation and evolution of Paleozoic reservoir bitumen in the Kongxi slope zone occurred in two main stages. The first-stage bitumen originated from Ordovician marine hydrocarbon source rocks, subsequently undergoing oxidative water washing and biodegradation during tectonic uplift stage. This bitumen retains compositional affinity with crude oils from Lower Paleozoic carbonate rocks. Second-stage bitumen formed through the thermal evolution of Carboniferous crude oil during deeper burial, showing compositional similarities with Carboniferous source rocks and their oil. This two-stage bitumen evolution indicates charging events in the Paleozoic reservoirs. While early uplift and exposure destroyed some paleo-reservoirs, unexposed areas within the Dagang oilfield may still contain preserved primary accumulations. Furthermore, second-stage hydrocarbon, dominated condensates derived from Carboniferous coal-bearing sequences since the Eocene, experienced limited thermal evolution to form some bitumen. These condensate accumulations remain the primary exploration target in the Paleozoic Formations. Full article
(This article belongs to the Special Issue Organic Petrology and Geochemistry: Exploring the Organic-Rich Facies)
Show Figures

Figure 1

Back to TopTop