Clastic dikes cause hazardous conditions in coal mines. Depositional history; coal geology and stratigraphy; previous studies; impact on mining; classification; joint-sourced dikes; mineralogy; coal petrology; interpretation; fault-fill dikes; channel-margin dikes; mining strategies. 48 pages. 30 figures. Digital PDF download. B-53D
Clastic dikes are common in North American coals that accumulated in marginal-marine environments, and they are rare-to-absent in coals that accumulated in continental settings. Clastic dikes are widespread in western Colorado coal fields where they intrude many thick coal seams. They are particularly abundant in coals mined in the southern part of the Piceance Basin, the focus of this study, near the towns of Palisade and Somerset.
Within the Piceance Basin, they have increased production costs and have caused a wide range of mining problems that have resulted in mine closures. The purpose of this study is to provide mine operators and researchers with information on the nature and composition of clastic dikes.