Depositional systems affect the thickness, geometry, extent, quality of coal seams, and the integrity of the associated roof and floor rocks. Moreover, post-depositional compaction may add complexities to coal seam geometry and impact economic recovery of coal and/or coalbed methane (CBM). Therefore, the evaluations of depositional systems and compactional features are important aspects of coal and CBM exploration and development. The following discussion is a cursory overview that introduces some key issues concerning depositional systems.
Depositional systems are laterally adjacent assemblages of sedimentary facies which are related by depositional processes (Scott and Fisher, 1969). Most coal originated from peat that was deposited as low-energy, coastal plain facies within fluvial (Pictures 1 and 2), strandplain/barrier (Pictures 3, 4, 5, 6, 7, 8, 9), and marine and lacustrine (Pictures 10 and 11) deltaic systems (Fisher and McGowen, 1967; McGowen, 1968; Fisher, 1969a, 1969b; Frazier and Osanik, 1969; Kaiser, 1974, 1978; Kaiser et al., 1978; Frazier et al., 1978; Horne et al., 1978; Ferm and Horne, 1979; Ayers, 1986; Donaldson and Eble, 1991; and Ayers et al., 1994).
Figures & Tables
This volume of the “Atlas of Coal Geology” provides 393 images on various subject matters related to coal deposits and coal resource utilization. The supporting text provides an introductory overview of coal exploration, mining, and coalbed methane (CBM) development, followed by discussions on various megascopic aspects of coal geology (microscopic aspects are covered in Volume 2). Because of the vast subject matter, many generalities had to be made in the text. References are included to guide those interested to more detailed discussions. All citations within the document are linked to the detailed reference list for this volume. The overriding theme for this publication is that a picture is worth a thousand words.