Evaluation of Dike-Flow Correlations Indicated by Geochemistry, Chief Joseph Swarm, Columbia River Basalt

摘要

A geochemical examination of dikes of a part of the Chief Joseph swarm, southeastern Washington-northeastern Oregon, and proximate Columbia River Basalt flows was conducted to evaluate the reliability of using comparative geochemistry to establish dike-flow correlations. An initial assessment of chemical variation, based on the major, minor, and selected trace element analyses of 48 dikes of the Grande Ronde River-Joseph Creek area (formerly known as the Grande Ronde swarm), revealed that although intradike chemical variation is minimal, interdike chemical variation is significant. Of the dikes surveyed, 32 are of Yakima chemical type, eight of Dodge chemical type, one of Roza chemical type, one of Umatilla chemical type, five of Pomona chemical type, and one of Lolo chemical type (chemical type nomenclature of Wright and others, 1973; Swanson and others, 1977). (ERA citation 05:006261)