TSOP and
Organic Petrology

This Society's objectives, as stated in its bylaws, include providing a forum and promoting research and interest in organic petrology.

See further discussion of TSOP's purpose.

Last modified 21 March 2010

What is Organic Petrology?


Transmitted light photomicrograph of bituminous coal showing vitrinite and cutinite

Organic Petrology is the branch of earth science dealing with the origin, occurrence, structure, and history of sedimentary organic matter (OM). Petrology is broader in scope than petrography, which is concerned mostly with the description and classification of sedimentary OM. Thus, organic petrology, broadly defined, includes virtually all aspects of OM-bearing rocks, and encompasses all possible analytical methods. The fields of organic petrology and organic geochemistry are covered in these general reference works.



Reflected light photomicrograph showing pyrite crystals in bituminous coal
The great complexity, heterogeneity, and non-crystalline nature of sedimentary OM poses difficult analytical challenges to organic petrologists. Investigation of such complex materials both requires effective classification system(s) and a diverse "grab bag" of analytical techniques. Historically, the optical microscope has provided one of the most useful tools in this effort, as it takes advantage of the remarkable ability of the human eye to recognize systematic patterns in complex systems; but emphasis in recent years has shifted more toward geochemical analysis methods, including solvent extraction, various pyrolysis methods, gas and liquid chromatography, mass spectroscopy, and nuclear magnetic resonance spectroscopy.


Photomicrograph in fluorescence mode showing telalginite in carbonate lacustrine sediments

One of the important functions of TSOP is to keep its members apprised of new developments in these diverse areas of specialization relating to organic petrology and to ensure that researchers around the world are "speaking the same language" and using reproducible methodologies in their investigations.

Procede to a discussion of the applications of organic petrology.