Abstract: Geologic Factors Used in Measuring Reclamation Potential of Western Land Underlain by Strippable Coal

H. E. Malde

Objectives for reclamation of western lands disturbed by surface mining of coal typically call for rehabilitation of the mined land to a former level of agricultural capacity and containment of mining impacts to the mined site. Accordingly, the potential for reclamation has been considered in terms of restoring vegetation and preventing offsite damage. Many geologic factors of terrain and water directly influence the degree to which these objectives can be achieved. Mining for strippable coal, for example, (1) causes the mined land to be raised or lowered in elevation, depending on the ratio of overburden to thickness of coal; (2) obliterates, or modifies, large and small irregularities of the original terrain; (3) interferes with surface water by changing stream gradient , sediment load, dissolved solids, flood discharge, channel shape, and channel position; and (4) changes conditions of ground water by removing aquifers, lowering the water table, reducing storage and rate of flow, increasing dissolved solids, and modifying areas of recharge. Because these circumstances of terrain and water place limits on reclamation achievements, full determination of reclamation potential requires measurement of such pertinent geologic, hydrologic, and geomorphic factors as variety and steepness of slope, diversity of landscape, conditions of erosion, density and character of surface drainage, nature of resistant outcrops, variations in soils and overburden, and structure of the coal deposits with respect to topography and water supply.

AAPG Search and Discovery Article #90979©1975 AAPG – SEPM Rocky Mountain Sections Annual Meeting, Albuquerque, New Mexico