An in depth interpretation of definition and classification of macerals in coal (ICCP system 1994) for Chinese researchers,I:Vitrinite

The international standard of the definition and classification of macerals in coal (i.e.,ICCP system 1994) has been fulfilled after 26 years (1991—2017).In terms of maceral groups and publication time,this standard has four parts,i.e.,vitrinite (1998),inertinite (2001),huminite (2005),and liptinite (2017).“ICCP system 1994” has now been widely adopted by international researchers of coal petrology and organic petrology.ICCP determined the definition and classification of vitrinite maceral groups,subgroups,and macerals in 1994 over the 46th ICCP annual meeting,which are important components of “ICCP system 1994”.In this classification system,the vitrinite group is classified into three maceral subgroups,namely telovitrinite,detrovitrinite,and gelovitrinite,each of which is further classified into two macerals.Maceral subgroups are defined by degree of destruction and macerals are defined by morphology and/or degree of gelification.The classification of vitrinite is closely related to that of huminite in “ICCP system 1994”.In this paper,the authors perform an in depth interpretation of the maceral subgroups and macerals of vitrinite to Chinese readers,including their definition,optical characteristics,physical and chemical properties,derivation,occurrence,and practical importance.The authors also tried their best to translate subgroups and macerals of vitrnite into correct Chinese in order to avoid any possible confusions for Chinese readers.In comparison with “ICCP system 1994”,the Chinese National Standard “Classification of Macerals in Bibuminous Coal” classifies the organic components into maceral groups,macerals,and submacerals,and classifies telocollinite (i.e.,collotelinite in the new classification system) and desmocollinite (i.e.,collodetrinitein the new classification system) into submacerals without structures.