Identification of Primary Vitrinite
MSc. Paul C. Hackley
U.S. Geological Survey
MS 956 National Center
12201 Sunrise Valley Dr.
Reston, VA 20192
Interlaboratory Study for ASTM D7708 Test Method for Dispersed Vitrinite Reflectance
A round robin exercise to develop precision statistics for ASTM D7708: Standard Test Method for Microscopical Determination of the Reflectance of Vitrinite Dispersed in Sedimentary Rocks is ongoing. Samples were sent to the participants in October 2012 and reflectance reports are due by March 31, 2013. Participants will measure vitrinite reflectance of six samples in duplicate. The samples range from immature to overmature, from the Paleozoic to the Cenozoic, and are from marine and lacustrine environments and coal measures. The samples range from 1 to 20 wt.% TOC. In other words, the samples are rich in variety and represent the full scope of materials expected to be reliably tested by ASTM D7708. Persons whom are interested in participating in the round robin are encouraged to contact Paul Hackley phackley_(at)_usgs.gov for more information.
Objectives and Results of the Working Group
The Identification of Primary Vitrinite WG was created at the Oviedo meeting in 2008 with the aim of providing guidelines for identification of the primary vitrinite population in dispersed organic matter. Results from recent years in Commission II regarding the qualification of vitrinite particles for measurement and the reappraisal of vitrinite reflectance measurements for a variety of source rocks have shown that the major problem associated with the measurement of vitrinite reflectance in dispersed organic matter is the identification of the primary vitrinite population. This has proven to be particularly difficult in low maturity organic-rich oil shales (Borrego et al., Int. J. Coal Geol. 68; 2006).
Although the success of the ICCP’s dispersed organic matter vitrinite reflectance accreditation program suggests that most petrographers are following a common methodology, until 2011 there was no standard test method for the reflectance measurement of dispersed vitrinite to guide analysts. This need was addressed by the members of this WG through the creation of ASTM D7708-11 Standard test method for microscopical determination of the reflectance of vitrinite dispersed in sedimentary rocks. This new test method is beginning to be adopted by ICCP members for dispersed organic matter vitrinite reflectance measurement.
Information and results of the working group to date include:
Hackley, P.C., Araujo, C.V., Borrego, A.G., Cardott, B.J., Cook, A.C. ,Hámor-Vidó, M., Kommeren, K., Mendonça Filho, J.G., Newman, J., Pawlewicz, M., Potter, J., Suárez-Ruiz, I., 2011, New ASTM standard test method for determination of the reflectance of vitrinite dispersed in sedimentary rocks: Program and Abstracts of the 28th Annual Meeting of the Society for Organic Petrology, Halifax, Nova Scotia, Canada, July 31-August 4, 2011, v. 28, p. 60-61.
Hackley, P.C., Araujo, C.V., Borrego, A.G., Cardott, B.J., Cook, A.C. ,Hámor-Vidó, M., Kommeren, K., Mendonça Filho, J.G., Newman, J., Pawlewicz, M., Potter, J., Suárez-Ruiz, I., 2011, New ASTM standard test method for determination of the reflectance of vitrinite dispersed in sedimentary rocks: American Association of Petroleum Geologists Eastern Section Meeting Program, Crystal City, Virginia, September 25-27, 2011, p. 33-34.
ASTM, 2011, D7708-11 Standard test method for microscopical determination of the reflectance of vitrinite dispersed in sedimentary rocks: 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, p. 823-830, doi: 10.1520/D7708-11, http://www.astm.org/Standards/D7708.htm.