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CONTACT

Paul Hackley
Lead Geologist
703.648.6458

Sharon Swanson
Lead Geologist
703.648.6453

Peter Warwick
Lead Geologist
703.648.6469

Laboratory Phone
703.648.6467

Organic Petrology Laboratory

Laboratory Overview	Management/ Preparation	Sample Analysis	Data QA/QC	Laboratory Reports

Sample Analysis Methodology

Vitrinite Reflectance Analyses

Reflectance analyses are conducted according to the ASTM Standard Test Method D 2798: Microscopical Determination of the Vitrinite Reflectance of Coal (ASTM, 2008).  The Laboratory uses several different standards for microscope calibration; a yttrium-aluminum-garnet (YAG) standard of 0.908% reflectance manufactured by Klein and Becker is employed for routine analyses.  One hundred measurements of the maximum or random reflectance of individual vitrinite grains in the sample are performed (for coal).  Fifty measurements are made on each sample mount.  In some cases, as when drill cuttings samples or organically-lean materials are analyzed, there is sometimes insufficient sample present to obtain 100 measurements.  There currently is no consensus standard for the measurement of the reflectance of dispersed vitrinite in petroleum source rocks; the ASTM standard referenced above (D 2798) is followed as practically as possible for this type of analysis.

Spectral Fluorescence Analyses

Spectral fluorescence measurements are conducted according to the methods described in Baranger and others (1991) using a Zeiss AxioImager microscope system equipped with a tin halide illumination source.  The light detection equipment consists of a photodiode array calibrated with the ESS Lamp described in Baranger and others (1991).  There currently is no consensus standard for the measurement of the spectral fluorescence of organic materials.

Petrographic Analyses

The type of petrographic analysis performed is dependent on the overall design and the specific scientific goals of individual projects.  Petrographic analyses usually are conducted according to the ASTM Standard Test Method D 2799: Microscopical Determination of the Maceral Composition of Coal (ASTM, 2008), or ISO standard 7404-3: Methods for the petrographic analysis of bituminous coal and anthracite-Part 3: Method of determining maceral group composition (ISO, 1994).  In some cases, a modification of the ASTM D 2799 test method is included to incorporate examination with fluorescence microscopy, primarily for low-rank samples (lignite-subbituminous).  For quantitative petrographic analysis, 500 identifications are performed per sample according to the ISO 7404-3 standard and 1000 identifications are performed per sample according to the ASTM D 2799 standard.  When the fluorescence microscopy modification of ASTM D 2799 is incorporated into the analysis, 2000 identifications are performed per sample – 1000 under tungsten halogen illumination and 1000 under xenon gas discharge (or other ultraviolet/blue light fluorescence source, e.g., metal halide) illumination.  Maceral nomenclature for huminite, vitrinite, and inertinite groups is according to the International Committee for Coal and Organic Petrology (ICCP) (ICCP, 1998, 2001; Sýkorová and others, 2005).  Maceral nomenclature for the liptinite group is according to Taylor and others (1998).  Mineral matter content of the sample is calculated according to the Parr Formula (ASTM, 2008) when ash yield and other pertinent data are available, and is checked against the petrographic point count.

Petrographic Laboratory Analytical Equipment

The microscope laboratory is equipped with an incident light Leitz Orthoplan microscope with photometer and peak detector for reflectance analysis, a Leica DMRX with mechanical stage and tungsten halogen and xenon gas discharge light sources for incident light compositional analysis, and a Leitz Orthoplan for examination of rock thin sections in transmitted polarized light.

Leitz Orthoplan incident light microscope with photometer and peak detection equipment for thermal maturation analysis.		Leica DMRX incident light microscope with mechanical stage and Swift F automated point counter for analysis of organic composition of coal and rock samples.

The Organic Petrology Laboratory contains a Leica M420 binocular microscope for macroscopic examination of sample mounts or larger sample blocks. A Leica DFC 480 digital camera can be mounted to each microscope for image capture.  Image analysis is conducted using ImagePro Plus software routines.

Leitz Orthoplan transmitted light microscope with Swift F automated point counter for textural and compositional analysis of rock samples in thin section.  A Leica DFC 480 digital camera is mounted on the microscope tube for image capture.		Leica M430 binocular microscope.

References:

ASTM, 2008, Annual book of ASTM standards: Petroleum products, lubricants, and fossil fuels; Gaseous fuels; coal and coke, sec. 5, v. 5.06: ASTM International, West Conshohocken, PA, 720 p.

Baranger, R., Martinez, L., Pittion, J., and Pouleau, J., 1991, A new calibration procedure for fluorescence measurements of sedimentary organic matter: Organic Geochemistry, v. 17, p. 467-475.

ISO, 1994, Methods for the petrographic analysis of bituminous coal and anthracite-Part 3: Method of determining maceral group composition: International Organization for Standardization Standard 7404-3, 6 p.

ICCP, 1998, The new vitrinite classification (ICCP System 1994): Fuel, v. 77, p. 349-358.

ICCP, 2001, The new inertinite classification (ICCP System 1994): Fuel, v. 80, p. 459-471.

Sýkorová, I., Pickel, W., Christanis, K., Wolf, M., Taylor, G.H., and Flores, D., 2005, Classification of huminite-ICCP System 1994: International Journal of Coal Geology, v. 62, p. 85-106.

Taylor, G.H., Teichmüller, M., Davis, A., Diessel, C.F.K., Littke, R., and Robert, P., 1998, Organic Petrology: Gerbrüder Borntraeger, Berlin, 704 p.

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