Fractures--joints and faults--affect the movement of fluids in rocks. Fracture permeability is important in sedimentary rocks that otherwise transmit water slowly, particularly limestone, dolomite, and fine-grained sandstone. A map of fracture traces may be used in assessing the spatial distribution of groundwater. The principal map in this report (scale 1:2,500 ,000) shows geologic structures and lineaments that affect the distribution of fracture traces in the sedimentary rocks of the High Plains and some adjacent areas. Potential fracture permeability is indicated on the map by 5 divisions, ranging from division 1 (smallest) to division 5 (largest potential fracture permeability). Geologic structure was the basis for delineating division boundaries. Generally, rocks in structurally uplifted areas and near conspicuous lineaments are more extensively fractured and have greater secondary permeability than rocks of structural basins. (USGS)
Additional Publication Details
USGS Numbered Series
Divisions of potential fracture permeability, based on distribution of structures and lineaments, in sedimentary rocks of the Rocky Mountains-High Plains region, Western United States
Water-Resources Investigations Report
1 map ; 72 x 69 cm., on sheet 89 x 132 cm., folded in envelope 31 x 24 cm.