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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

Inter-Laboratory Comparison and Analyst Accreditation

The U.S. Geological Survey Organic Petrology Laboratory participates in a quarterly round robin inter-laboratory exercise hosted by a commercial laboratory (CoalTech Petrographic Associates, Inc.).  Results of the exercise are used to evaluate the precision and bias of our analytical methods, to develop proficiency in analyses of different sample types, to correct deficiencies in analytical techniques, and to develop evidence of the repeatability and reproducibility of analytical methods.  The Organic Petrology Laboratory also participates in the round robin exercises of the relevant working groups of ICCP (e.g., Thermal Indices, Concentration of Organic Matter, Identification of Dispersed Organic Matter, and Standardization).

Plot of individual vitrinite reflectance result with group mean result for random and maximum vitrinite reflectance of coal and random reflectance of vitrinite dispersed in sedimentary rocks. Error bars (dark gray) show one standard deviation of group mean. Data are from the participation of Paul Hackley in various ICCP accreditation programs, ICCP working groups, and commercial round robin exercises from 2004 to present (May, 2009). Current average absolute difference from the group mean is 0.05%. [number of samples = 37; Ro range = 0.3-1.8%].

Plot of individual percent vitrinite result with group mean result for lignite to low volatile bituminous coals. Error bars (dark gray) show one standard deviation of group mean. Data are from the participation of Paul Hackley in various ICCP accreditation programs, ICCP working groups, and commercial round robin exercises from 2004 to present (May, 2009). Current average absolute difference from the group mean is 3.7%. [number of samples = 26; percent vitrinite ranges from 50–90%].

Petrographers in the Laboratory maintain accreditation in methods of coal and dispersed organic matter petrographic analysis from the ICCP.  Accreditation information, certificate number, and expiration date are given in the footer material of individual sample reports and are available at the laboratory overview webpage.

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