Organic Petrology Laboratory
Composition of Laboratory Reports
Results of petrographic analyses of coal and rock samples in the U.S. Geological Survey Organic Petrology Laboratory usually are reported in several parts; 1) summary tables, 2) vitrinite reflectance reports, 3) petrographic reports, and 4) spectral fluorescence reports.
Summary tables encapsulate the most important numerical results of petrographic analyses of a sample suite (e.g., reflectance values) and may be prepared as Excel spreadsheet files, components of a slide presentation, or in portable document format (.pdf). The format of presentation is dependent upon the needs of the investigation.
The vitrinite reflectance report includes five components; 1) basic sample information including sample submitter, submission date, project name, sample identification, sample type, date of analysis, and the name of the analyst, 2) results, including the number of reflectance measurements, the type of organic material analyzed, the mean maximum or mean random reflectance value, the standard deviation of the mean reflectance value, and the sample rank, 3) data, including the measured reflectance values in percent to three decimal places, the maximum and minimum measured values, and the number of V-types (reflectance ranges of 0.1 percent), 4) a histogram of the reflectance data, and 5) a comment section listing pertinent details about the petrographic character of the sample.
The petrographic analysis report includes five components; 1) a header with basic sample information including sample submitter, submission date, project name, sample identification, sample type, date of analysis, the name of the analyst, the number of points counted, and the sample rank as determined by vitrinite reflectance, 2) a bar chart showing gross maceral group composition on a mineral-matter-free basis (volume percent of organic matter basis), 3) a bar chart showing organic composition on a mineral-containing basis (volume percent of whole coal/rock), 4) a data table listing the abundance of the individual organic components on mineral-containing and mineral-free bases, and 5) a comment section listing pertinent details about the petrographic character of the sample.
The spectral fluorescence report includes 1) basic sample information, 2) results, including mean spectral parameters λmax, Q650/500, Qmax/500, Hw, and Rh (see Bustin and others, 1985), 3) an example photograph of the analyzed material, 4) spectral signatures and a calculated mean spectrum, 5) raw data measurements, and 6) a comment section for the analyst to provide sample documentation.
References:
Bustin, R.M., Cameron, A.R., Grieve, D.A., and Kalkreuth, W.D., 1985, Coal petrology: its principles, methods, and applications: Short Course Notes, Geological Association of Canada, v. 3, 229 p.
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