ASTM D7708-14

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Designation: D7708 − 11 D7708 − 14
Standard Test Method for
Microscopical Determination of the Reflectance of Vitrinite
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Dispersed in Sedimentary Rocks
This standard is issued under the fixed designation D7708; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope
1.1 This test method covers the microscopical determination of the reflectance measured in oil of polished surfaces of vitrinite
dispersed in sedimentary rocks. This test method can also be used to determine the reflectance of macerals other than vitrinite
dispersed in sedimentary rocks.
1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility
of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory
limitations prior to use.
2. Referenced Documents
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2.1 ASTM Standards:
D121 Terminology of Coal and Coke
D388 Classification of Coals by Rank
D2797 Practice for Preparing Coal Samples for Microscopical Analysis by Reflected Light
D2798 Test Method for Microscopical Determination of the Vitrinite Reflectance of Coal
E177 Practice for Use of the Terms Precision and Bias in ASTM Test Methods
E691 Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method
3. Terminology
3.1 Definitions—For definitions of terms, refer to Terminology D121.
3.2 Abbreviations:
3.2.1 R ran—mean random reflectance measured in oil. Other organizations may use other abbreviations for mean random
o
reflectance.
3.3 Definitions of Terms Specific to This Standard:
3.3.1 alginite, n—a liptinite maceral occurring in structured morphologies, telalginite, and unstructured morphologies,
lamalginite.
3.3.2 bituminite, n—an amorphous primary liptinite maceral with low reflectance, occasionally characterized by colored internal
reflections and weak orange-brown fluorescence, derived from bacterial biomass and the bacterial decomposition of algal material
and faunal plankton. Bituminite is equivalent to the amorphous organic matter recognized in strew slides of concentrated kerogen
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(1).
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This test method is under the jurisdiction of ASTM Committee D05 on Coal and Coke and is the direct responsibility of Subcommittee D05.28 on Petrographic Analysis
of Coal and Coke.
Current edition approved April 1, 2011May 1, 2014. Published April 2011May 2014. Originally appeared in 2011 as D7708-11. DOI: 10.1520/D7708–11.10.1520/
D7708–14.
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For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
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The boldface numbers in parentheses refer to a list of references at the end of this standard.
3.3.2.1 Discussion—
Bituminite may be distinguished from vitrinite by lower reflectance, as well as higher fluorescence intensity if fluorescence is
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D7708 − 14
present in vitrinite. Bituminite has poorly-defined wispy boundaries and may be speckled or unevenly colored whereas vitrinite
has distinct boundaries and is blockier and evenly colored. The occurrence of bituminite in association with lamalginite and
micrinite is common. Rock type, thermal maturity, and geologic occurrence can be used to interpret the potential presence of
bituminite; for example, bituminite may be expected to occur in lacustrine or marine settings. It is less commonly present in fluvial
or similar proximal depositional environments, where vitrinite may be expected to occur in greater abundance.
3.3.3 chitinozoan, n—a group of flask-shaped, sometimes ornamented marine microfossils of presumed metazoan origin which
are composed of ’pseudochitin’ proteinic material and which occur individually or in chains. Chitinozoan cell walls are thin,
opaque to translucent, and range from dark gray to white in reflected white light similar to vitrinite. Chitinozoans are common in
Ordovician to Devonian marine shales.
3.3.4 conodont,
...