Vitrinite is a maceral group that is derived from the remains of woody material from vascular plants and is composed of the thermally evolved products of lignin and cellulose. A maceral group is a set of organic matter types with similar properties and appearance. Vitrinite reflectance measures the percentage of incident light that is reflected from the surface of vitrinite as calibrated to a standard of known reflectance. This measurement is often regarded as the gold standard thermal maturity parameter and is used in oil and gas resource assessment and basin analysis studies. The Organic Petrology Laboratory (OPL) in Reston provides vitrinite reflectance measurements and qualitative organic petrography of shale, coal, and other unconventional reservoir samples as a routine service for various USGS Science Centers and external collaborators.
Objectives:
This project area has two main objectives. The first is to provide routine vitrinite reflectance measurements for Energy Resources Program-funded projects, the broader USGS community, and external partners. The second is to provide routine laboratory support functions for sample preparation for various analyses and micro-Fourier transform infrared spectroscopy (FTIR) research. These objectives allow for collaboration or case study investigations that reduce uncertainty in energy resource assessments, energy processes research, and environmental assessments.
Methodology:
Using equipment for preparation of mounted sample briquettes and several optical microscope systems (vitrinite reflectance, spectral fluorescence, transmitted polarized light microscopy) with imaging capability, laboratory staff provide quantitative vitrinite reflectance and qualitative organic petrographic data to internal and external customers using a Laboratory Information Management System (LIMS) per the requirements of the USGS Quality Management System (QMS). Measurement of vitrinite reflectance follows ASTM International method D7708 or D2798. In addition to vitrinite reflectance measurement, current laboratory processes also include sample preparation (mounting, grinding, polishing, wafering), transmitted light petrography, creation of sample maps through image stitching, spectral fluorescence measurement, and micro-FTIR analysis. Petrographers in the OPL pursue external accreditation in the specialized techniques of organic petrology investigation. The OPL has participated continuously since 2005 in a quarterly coal petrography interlaboratory exercise as a quality control check and operates under the requirements of the USGS QMS since 2017 to ensure that all data are of known and documented quality.
Listed below are other science projects or tasks associated with this task.
Petrographic Thermal Indices Research
Thermal Indices Innovation
Standardization of Petrographic Thermal Indices
Hydrous Pyrolysis and Kerogen Conversion
Listed below are data products associated with this project.
Reflectance measurements for eight samples submitted to the USGS Organic Petrology Laboratory in Reston
Textural occurrence and organic porosity of solid bitumen in shales
TOC, Reflectance and Raman Data from Eocene Green River Mahogany Zone
Reflectance, Raman band separation and Mean multivariant curve resolution (MCR) in organic matter in Boquillas Shale
Bitumen Reflectance Data from the Tattoo Well in the Horn River Basin, Sample E200205
USGS Gulf Coast Source Rock Database
Nanoscale Molecular Composition of Solid Bitumen from the Eagle Ford Group Across a Natural Thermal Maturity Gradient
Oil-source rock correlation studies in the unconventional Upper Cretaceous Tuscaloosa marine shale petroleum system, Mississippi and Louisiana, USA (2019)
Petroleum geology data from Cenozoic rock samples in the eastern U.S. Gulf Coast collected 2014 to 2016
Petroleum geology data from Mesozoic rock samples in the eastern U.S. Gulf Coast collected 2011 to 2017
Listed below are publications associated with this project.
Mapping ancient sedimentary organic matter molecular structure at nanoscales using optical photothermal infrared spectroscopy
Maturation study of vitrinite in carbonaceous shales and coals: Insights from hydrous pyrolysis
Evaluating aromatization of solid bitumen generated in the presence and absence of water: Implications for solid bitumen reflectance as a thermal proxy
The effect of diagenesis and acetolysis on the preservation of morphology and ultrastructural features of pollen
Finalization of the Confocal Laser Scanning Microscopy (CLSM) working group
Identification of thermal maturity-relevant organic matter in Shale Working Group Report 2021
Molecular mechanisms of solid bitumen and vitrinite reflectance suppression explored using hydrous pyrolysis of artificial source rock
Characterization of bituminite in Kimmeridge Clay by confocal laser scanning and atomic force microscopy
The Confocal Laser Scanning Microscopy Working Group of the ICCP: Final report 2021
New insights into organic matter accumulation from high-resolution geochemical analysis of a black shale: Middle and Upper Devonian Horn River Group, Canada
Vitrinite reflectance analysis
Hydrous pyrolysis of New Albany Shale: A study examining maturation changes and porosity development
Listed below are online interactive applications associated with this project.
Photomicrograph Atlas
A database of images related to the characterization of fossil fuel resources in the United States and the world.
- Overview
Vitrinite is a maceral group that is derived from the remains of woody material from vascular plants and is composed of the thermally evolved products of lignin and cellulose. A maceral group is a set of organic matter types with similar properties and appearance. Vitrinite reflectance measures the percentage of incident light that is reflected from the surface of vitrinite as calibrated to a standard of known reflectance. This measurement is often regarded as the gold standard thermal maturity parameter and is used in oil and gas resource assessment and basin analysis studies. The Organic Petrology Laboratory (OPL) in Reston provides vitrinite reflectance measurements and qualitative organic petrography of shale, coal, and other unconventional reservoir samples as a routine service for various USGS Science Centers and external collaborators.
Objectives:
This project area has two main objectives. The first is to provide routine vitrinite reflectance measurements for Energy Resources Program-funded projects, the broader USGS community, and external partners. The second is to provide routine laboratory support functions for sample preparation for various analyses and micro-Fourier transform infrared spectroscopy (FTIR) research. These objectives allow for collaboration or case study investigations that reduce uncertainty in energy resource assessments, energy processes research, and environmental assessments.
Methodology:
Using equipment for preparation of mounted sample briquettes and several optical microscope systems (vitrinite reflectance, spectral fluorescence, transmitted polarized light microscopy) with imaging capability, laboratory staff provide quantitative vitrinite reflectance and qualitative organic petrographic data to internal and external customers using a Laboratory Information Management System (LIMS) per the requirements of the USGS Quality Management System (QMS). Measurement of vitrinite reflectance follows ASTM International method D7708 or D2798. In addition to vitrinite reflectance measurement, current laboratory processes also include sample preparation (mounting, grinding, polishing, wafering), transmitted light petrography, creation of sample maps through image stitching, spectral fluorescence measurement, and micro-FTIR analysis. Petrographers in the OPL pursue external accreditation in the specialized techniques of organic petrology investigation. The OPL has participated continuously since 2005 in a quarterly coal petrography interlaboratory exercise as a quality control check and operates under the requirements of the USGS QMS since 2017 to ensure that all data are of known and documented quality.
- Science
Listed below are other science projects or tasks associated with this task.
Petrographic Thermal Indices Research
A petrographic thermal index is typically an organic matter indicator in sedimentary rocks that allows for estimations of burial temperature. Petrographic thermal indices include the commonly used proxy vitrinite reflectance as well as other approaches such as solid bitumen reflectance, fluorescence, micro-Raman, and micro-Fourier transform infrared (FTIR) spectroscopies. Measurements from these...Thermal Indices Innovation
Thermal indices innovation focuses on the utilization of correlative microscopy and spectroscopy techniques for innovative approaches to advance the understanding of thermal indices development. These techniques include correlative light and electron microscopy (CLEM), confocal laser scanning microscopy (CLSM), and atomic force microscopy and infrared microscopy (AFM-IR), among others. Use of...Standardization of Petrographic Thermal Indices
Advent of the shale revolution since about 2005 caused increased demand for reliable petrographic measurements of thermal maturity in shale via vitrinite reflectance, which has long been considered the gold standard approach. The first standardized methodology for vitrinite reflectance measurement in shale became available in 2011. Subsequent interlaboratory studies demonstrated that significant...Hydrous Pyrolysis and Kerogen Conversion
Hydrous pyrolysis (HP) experimentation is a laboratory method used to thermally mature organic-rich sedimentary rocks. It simulates petroleum generation in the closest available analogue to that of a natural system. Artificial maturation of sedimentary organic matter (SOM) to petroleum allows for the examination of its molecular chemistry to address the issue of anomalous reflection measurement... - Data
Listed below are data products associated with this project.
Reflectance measurements for eight samples submitted to the USGS Organic Petrology Laboratory in Reston
This data release contains reflectance measurements for eight samples submitted to the USGS Organic Petrology Laboratory in Reston. Samples include two artificial rock samples made from cement with organic matter added (samples 001-002), a coal and shale sample (samples 003-004, respectively), and hydrous pyrolysis residues for samples 001-004. The hydrous pyrolysis experiments were conducted at 3Textural occurrence and organic porosity of solid bitumen in shales
This study presents Raman spectroscopic data paired with scanning electron microscopy (SEM) to assess solid bitumen composition and porosity development as a function of solid bitumen texture and association with minerals. A series of hydrous pyrolysis experiments (1-103 days, 300-370°C) using a low maturity (0.25% solid bitumen reflectance, BRo), high total organic carbon [(TOC), 14.0 wt. %] NewTOC, Reflectance and Raman Data from Eocene Green River Mahogany Zone
Geological models for petroleum generation suggest thermal conversion of oil-prone sedimentary organic matter in the presence of water promotes increased liquid saturate yield, whereas absence of water causes formation of an aromatic, cross-linked solid bitumen residue. To test the influence of exchangeable hydrogen from water, organic-rich (22 wt. percent total organic carbon, TOC) mudrock sampleReflectance, Raman band separation and Mean multivariant curve resolution (MCR) in organic matter in Boquillas Shale
The molecular composition of petroliferous organic matter and its composition evolution throughout thermal advance are key to understanding and insight into petroleum generation. This information is critical for comprehending hydrocarbon resources in unconventional reservoirs, as source rock organic matter is highly dispersed, in contact with the surrounding mineral matrix, and may be present as mBitumen Reflectance Data from the Tattoo Well in the Horn River Basin, Sample E200205
Bitumen reflectance data from a sample collected from the vertical EOG TATTOO D129 A28-F/094-O-10 ("Tattoo") well in the Horn River Basin, as part of the collection of a high-resolution geochemical data set.USGS Gulf Coast Source Rock Database
The USGS Gulf Coast Source Rock Database (GCSRD) is an online repository for all publicly available source rock data (outcrop and subsurface) from the states of Florida, Georgia, Alabama, Mississippi, Louisiana, Arkansas, and Texas. "Source rock data" are defined in this context as data that include any of the following measured or calculated parameters: - Total organic carbon (TOC) - VaNanoscale Molecular Composition of Solid Bitumen from the Eagle Ford Group Across a Natural Thermal Maturity Gradient
Solid bitumen is a petrographically-defined secondary organic matter residue produced during petroleum generation and subsequent oil transformation. The presence of solid bitumen impacts many shale reservoir properties including porosity, permeability, and hydrocarbon generation and storage, amongst others. Furthermore, solid bitumen reflectance is an important parameter for assessing the thermalOil-source rock correlation studies in the unconventional Upper Cretaceous Tuscaloosa marine shale petroleum system, Mississippi and Louisiana, USA (2019)
The U.S. Geological Survey assessed undiscovered unconventional hydrocarbon resources reservoired in the Upper Cretaceous Tuscaloosa marine shale (TMS) of southern Mississippi and adjacent Louisiana in 2018. As part of the assessment, oil- source rock correlations were examined in the study area where operators produce light (38-45 degrees API), sweet oil from horizontal, hydraulically-fractured wPetroleum geology data from Cenozoic rock samples in the eastern U.S. Gulf Coast collected 2014 to 2016
The U.S. Geological Survey assessed undiscovered petroleum resources in the downdip Paleogene formations of the U.S. Gulf Coast in 2018. During the assessment new data and information were collected to evaluate thermal maturity, source rock character, and unconventional reservoir rock prospectivity for the Cenozoic-aged section in south Louisiana. Samples were analyzed using multiple analytical apPetroleum geology data from Mesozoic rock samples in the eastern U.S. Gulf Coast collected 2011 to 2017
This data release contains Rock-Eval pyrolysis, organic petrographic (reflectance), and X-ray diffraction mineralogy data for subsurface Mesozoic rock samples from the eastern onshore Gulf Coast Basin (primarily Mississippi and Louisiana). Samples were analyzed in support of the U.S. Geological Survey (USGS) assessment of undiscovered petroleum resources in the Upper Cretaceous Tuscaloosa marine s - Publications
Listed below are publications associated with this project.
Filter Total Items: 41Mapping ancient sedimentary organic matter molecular structure at nanoscales using optical photothermal infrared spectroscopy
Elucidating the molecular structure of sedimentary organic matter (SOM) is key to understanding petroleum generation processes, as well as ancient sedimentary environments. SOM structure is primarily controlled by biogenic source material (e.g., marine vs. terrigenous), depositional conditions, and subsurface thermal history. Additional factors, e.g., strain, may also impact the molecular structurAuthorsAaron M. Jubb, Martha (Rebecca) Stokes, Ryan J. McAleer, Paul C. Hackley, Eoghan Dillion, Jing QuMaturation study of vitrinite in carbonaceous shales and coals: Insights from hydrous pyrolysis
The presence of vitrinite in sedimentary rocks of post-Silurian age allows its reflectance to be used to estimate the thermal maturation of organic matter in petroleum systems. Increasing reflectance of vitrinite, which is primarily driven by aromaticity, depends primarily on the time and temperature attributes of its evolutionary pathway. This study evaluated carbonaceous shales proximal to coalAuthorsDivya K. Mishra, Paul C. Hackley, Aaron M. Jubb, Margaret M. Sanders, Shailesh Agrawal, Atul K. VarmaEvaluating aromatization of solid bitumen generated in the presence and absence of water: Implications for solid bitumen reflectance as a thermal proxy
Geological models for petroleum generation suggest thermal conversion of oil-prone sedimentary organic matter in the presence of water promotes increased liquid saturate yield, whereas absence of water causes formation of an aromatic, cross-linked solid bitumen residue. To test the influence of hydrogen from water, organic-rich (22 wt% total organic carbon, TOC) mudrock samples from the Eocene lacAuthorsPaul C. Hackley, Aaron M. Jubb, Patrick L. Smith, Ryan J. McAleer, Brett J. Valentine, Javin J. Hatcherian, Palma J. Botterell, Justin E. BirdwellThe effect of diagenesis and acetolysis on the preservation of morphology and ultrastructural features of pollen
Pollen morphology on its own and in conjunction with other characteristics has elucidated the origin and evolution of various plant groups. Previous studies of fossil pollen rarely discuss the effects of diagenesis and sample preparation on pollen characteristics, i.e., variability in staining, pollen morphology, and pollen wall ultrastructural characteristics. This paper examines the effect of acAuthorsMichael Zavada, Paul C. HackleyFinalization of the Confocal Laser Scanning Microscopy (CLSM) working group
A working group in Commission II to investigate applications of confocal laser scanning microscopy (CLSM) for organic petrology investigations has finalized with publication of the manuscript “Characterization of bituminite in Kimmeridge Clay by confocal laser scanning and atomic force microscopy” in the International Journal of Coal Geology. The manuscript is available via Open Access from https:AuthorsPaul C. Hackley, Jolanta KusIdentification of thermal maturity-relevant organic matter in Shale Working Group Report 2021
The Identification of Thermal Maturity-Relevant Organic Matter in Shale Working Group of the ICCP was established in 2008 to provide guidelines for identifying and measuring the reflectance of the population of dispersed organic matter that is relevant to thermal maturity determination. Information products published by the working group include ASTM D7708 Standard Test Method for Microscopical DeAuthorsPaul C. Hackley, Javin J. Hatcherian, Jennifer L. Rivera, Margaret M. Sanders, Brett J. ValentineMolecular mechanisms of solid bitumen and vitrinite reflectance suppression explored using hydrous pyrolysis of artificial source rock
The most commonly used parameter for thermal maturity calibration in basin modelling is mean random vitrinite reflectance (Ro). However, Ro suppression has been noted in samples containing a high proportion of liptinite macerals. This phenomenon has been demonstrated empirically using hydrous pyrolysis of artificial source rock containing various proportions of thermally immature Wyodak-Anderson cAuthorsMargaret M. Sanders, Aaron M. Jubb, Paul C. Hackley, Kenneth E. PetersCharacterization of bituminite in Kimmeridge Clay by confocal laser scanning and atomic force microscopy
This work investigates bituminite (amorphous sedimentary organic matter) in Upper Jurassic Kimmeridge Clay source rock via confocal laser scanning microscopy (CLSM) and atomic force microscopy (AFM). These petrographic tools were used to provide better understanding of the nature of bituminite, which has been historically difficult to identify and differentiate from similar organic matter types inAuthorsPaul C. Hackley, Jolanta Kus, João Graciano Mendonça Filho, Andrew D. Czaja, Angeles G. Borrego, Dragana Životić, Brett J. Valentine, Javin J. HatcherianThe Confocal Laser Scanning Microscopy Working Group of the ICCP: Final report 2021
This report summarizes the activities and results of the Confocal Laser Scanning Microscopy (CLSM) working group (WG) of the International Committee for Coal and Organic Petrology (ICCP), from its inception in September, 2015, to the present day (September, 2021). The purpose of this report is to document the history of the working group and to compile and evaluate its results. The CLSM WG examineAuthorsPaul C. Hackley, Jolanta Kus, João Graciano Mendonça Filho, Andrew D. Czaja, Angeles Borrego, Dragana ŽivotićNew insights into organic matter accumulation from high-resolution geochemical analysis of a black shale: Middle and Upper Devonian Horn River Group, Canada
Organic matter (OM) accumulation in organic matter-rich mudstones, or black shales, is generally recognized to be controlled by combinations of bioproductivity, preservation, and dilution. However, specific triggers of OM deposition in these formations are commonly difficult to identify with geochemical proxies, in part because of feedbacks that cause geochemical proxies for these controls to varyAuthorsHaolin Zhou, Nicholas B. Harris, Tian Dong, Korhan Ayranci, Jilu Feng, Benoit Rivard, Paul C. Hackley, Javin J. HatcherianVitrinite reflectance analysis
Vitrinite is a maceral group (a set of organic matter types with similar properties and appearance) derived from the remains of woody material from vascular plants and is composed of the thermally evolved products of lignin and cellulose. Vitrinite is the dominant component of humic coal and is found as a minor component dispersed into sedimentary rocks, especially mudrocks, the primary source rocAuthorsPaul C. HackleyHydrous pyrolysis of New Albany Shale: A study examining maturation changes and porosity development
The characterization of nanoscale organic structures has improved our understanding of porosity development within source-rock reservoirs, but research linking organic porosity evolution to thermal maturity has generated conflicting results. To better understand this connection, an immature (0.25% solid bitumen reflectance; BRo) sample of the New Albany Shale was used in four isothermal hydrous pyAuthorsBrett J. Valentine, Paul C. Hackley, Javin J. Hatcherian - Web Tools
Listed below are online interactive applications associated with this project.
Photomicrograph Atlas
A database of images related to the characterization of fossil fuel resources in the United States and the world.