El Paso Group  search
BTChronostratigraphic Units
 .Phanerozoic
 ..Paleozoic
 ...Ordovician
 ....Lower Ordovician
 .....El Paso Group
RTNew Mexico
 Texas
 Arizona
SNSE Arizona, S New Mexico and W Texas. Also search El Paso Formation NOT Argentina. Added to Thesaurus in 1989.