Geology Reference
In-Depth Information
Table 3.1.1
Classification of macerals into subgroups and groups, based on the international committee for coal and
organic petrology (ICCP, 1998, 2001), the Australian Standard System of nomenclature (AS, 1995), and the
American Society for Testing and Materials (ASTM, 1996).
Maceral
group
Maceral
subgroup
Maceral (AS
3856-1986)
Maceral (ASTM D
2799)
Maceral (ICCP, 1998, 2001)
Vitrinite
Telovitrinite
Telinite
Collotelinite
Textinite
*
Texto-ulminite
*
Eu-ulminite
*
Telocollinite
Vitrinite
Detrovitrinite
Vitrodetrinite
Collodetrinite
Attrinite
*
Densinite
*
Desmocollinite
Gelovitrinite
Gelinite
Corpogelinite
Corpogelinite
Porigelinite
*
Eugelinite
Liptinite
Sporinite
Cutinite
Resinite
Exsudatinite
Chlorophyllinite
Suberinite
Alginite (var. lamalginite,
telalginite)
Bituminite
Liptodetrinite
Sporinite
Cutinite
Resinite
Liptodetrinite
Alginite
Suberinite
Fluorinite
Exsudatinite
Bituminite
Sporinite
Cutinite
Resinite
Alginite
Inertinite
Telo-inertinite
Fusinite
Semifusinite
Funginite
Secretinite
Fusinite
Semifusinite
Sclerotinite
Fusinite
Semifusinite
Sclerotinite
Inertodetrinite
Inertodetrinite
Inertodetrinite
Detro-inertinite Micrinite
Micrinite
Micrinite
Macrinite
Macrinite
Macrinite
Gelo-inertinite
*
Refers to brown coal (low-rank) macerals, otherwise the vitrinite classification is for medium and high-rank coals.
macerals are enriched in hydrogen, owing to a greater amount of aliphatic components. Therefore, alginite
(the remains of algae) and other hydrogen-rich components such as bituminite are also included in
this group. Liptinite is fluorescent at lower coal ranks, and the fluorescent color and the intensity of
fluorescence help identify individual macerals of this group. In higher rank coals, liptinite loses its
fluorescence and is generally indistinguishable from vitrinite due to the convergence of reflectances of the
maceral groups.
The inertinite maceral group (Figure 3.1.3) originates from the same material as the vitrinite group and the
liptinite group, but has a higher degree of aromatization and condensation. Inertinite macerals have a greater
carbon content than vitrinite group macerals at the same rank because they were carbonized, oxidized, or subjected
to chemical or bacterial attacks prior to coalification, usually in the peat stage. Under reflected light microscope,
macerals of inertinite group are lighter (higher reflectance) compared to vitrinite macerals. Cell structure is very
well preserved in fusinite and significantly less preserved in semifusinite. Other macerals of this group are
distinguished based on their gelification degree (macrinite) or their high reflectance (micrinite). The fusinite and
semifusinite macerals of this group are formed, in part, as a result of wildfires, and their reflectance is directly
related to the fire temperature.
