Interpreting the characteristics of coal seams from chemical, physical and petrographic studies of peat deposits

Abstract

The purpose of this paper is to illustrate some of the kinds of information about coals that are at present being generated from studies of peat deposits and also to point out some possible new areas of research that might be undertaken in the future. Some notable examples of new ideas about coal seam composition or formation that have been generated from studies of modern peat deposits include: (1) discovery of the probable progenitors of certain coal macerals and elucidation of the processes by which they may have formed; (2) evidence that some types of mineral matter may be dissolved out of peat deposits; (3) verification of the role of marine waters in emplacement of sulphur in peat; (4) discovery of the importance of ‘doming’ in peat deposit development; (5) discovery of a new way to form a split in a coal seam, i.e. development of a ‘fire splay’; (6) elucidation of the mechanisms responsible for producing stratification in coal seams; (7) recognition of the world-wide importance of ‘back-barrier’ coal-forming environments. These kinds of discoveries are important in themselves; however, they can also be shown to have many additional practical applications, especially if woven into models to predict the economic characteristics of coal seams.

Petrographic characteristics and paleoenvironmental history of Eocene lignites of Cambay basin, Western India

“…Petrography based facies models have been used to discuss the evolutionary history of the paleomires of the Cambay basin. Using petrological tools a number of researchers have successfully performed paleoecological reconstructions and contributions have been made by Cohen and Spackman (1972), Styan and Bustin (1983), Cohen et al (1987), Calder et al (1991), Grady et al (1993), Hawke et al (1996), Singh and Singh (1996), Shearer and Clarkson (1998), Sun et al (1998), Dai et al (2007), Jasper et al (2010), Singh et al (2010a, b), Deng and Sun (2011), and Singh et al (2012a, b, c, d). Detro-huminite is throughout high in the lignites of Cambay basin wherein densinite is more consistent.…”

A Comparison of Maceral and Microlithotype Indices for Interpretation of Coals in the Samarinda Area, Lower Kutai Basin, Indonesia

“…less than 30%. The petrological composition of coal seams is a key to understand the evolution of peat-forming depositional environments [3,[19][20][21][22][23][24][25][26] and many others. However, the reconstruction and interpretation of Samarinda coals cannot be solely based on coal facies change (I-III), as most coals were grouped as Group I.…”

“…The maceral compositions, obtained through petrographic analysis, necessarily characterize the paleomires, since they depend on plant as well as the environment. Several researchers [20,[30][31][32][33][34][35] have correlated the petrographic components of coal with the paleoecological conditions. Teichmüller, 1989 [22] showed that depositional environment can be assessed through the presence or absence of certain macerals and, thus, maceral indices are useful in order to depict some genetic features of coals.…”

Petrological Investigations of Oligocene Coals from Foreland Basin of Northeast India

“…Coal petrography based models can help in reconstruction of the depositional environments of the paleomire. It is believed that plants react to the changes in the environmental conditions very sensitively and the petrographic study can enable us to understand facies (Teichmüller and Teichmüller, 1975;Cohen and Spackman, 1972;Cohen et al, 1987;Grady et al, 1993;Hawke et al, 1996;Hawke et al, 1999;Shearer and Clarkson, 1998;Styan and Bustin, 1983;Singh and Singh, 1996). In recent years successful attempts have been made by several researchers to relate the petrographic components with the paleodepositional environment (Duan et al, 2011;Deng and Sun, 2011;Singh et al, 2010a,b;2012a,b).…”