The lithology ctnd approximate thickness of the strata being penetrated during drilUng can be monitored by describing the cuttings after they are separated from the borehole fluid returns. Precise description of the cuttings is necessary for determining the depth and type of marker strata above and below the targeted coal seam as well as the depth and thickness of the coal seam. Precise descriptions of drill cuttings is especially important if core is not taken and critical if geophysical logs are not run. Cuttings should be collected at regular depths to avoid problems with lag time when penetration rates vary.