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Radiometric ages of igneous rocks from Pima, Santa Cruz, and Cochise counties, southeastern Arizona
The U.S. Geological Survey has determined, by the K-Ar, Rb-Sr, and Ph-a methods, 126 radiometric ages of samples from the southeast corner of Arizona. All the data pertaining to these determinations, including both published and unpublished data, are assembled in tabular form. The radiometric ages of the samples indicate that during the Phanerozoic, from Triassic to Pliocene, the region experienced periods of plutonic and volcanic activity. Many of the exposed Precambrian rocks have a geologicdoi:10.3133/b1379 fatcat:lmq7lq3ov5cohifgged2jtvhxi