Paleochannels are sedimentary rock units deposited by ancient streams that transported sediment through the peat mire. As discussed in the section on Coal Depositional Systems, paleochannels constitute the framework facies that bound the mire. The most adverse impact of a paleochannel is their potential to fully erode a coal seam (Picture 1). They also cause adverse roof and highwall conditions in underground and surface mines, respectively. Depositional modeling of the coal deposit, in particular, delineation of the paleodrainage patterns, is important in the design and layout of a coal mine and for optimizing CBM production.
Paleochannels also are termed "channels", "wants" (underground miners in want of coal), "cutouts", "washouts", and "rolls". They are very common in coal-bearing strata and occur in deposits throughout the world (Pictures 2, 3, and 4).