Biogechemical reconnaissance of the Annie Laurie uranium prospect, Santa Cruz County, Arizona

Abstract

A survey of the radioactivity of the vegetation growing on a uranium deposit near Ruby, Arizona, was made in the summer of 1954. The plant ash was analyzed for radioactivity by the alpha scintillation method. The uranium occurs as a zone of irregular pitchblende mineralization in a highly fractured rhyolite porphyry that overlies a series of sandstones, limestones, and shales. The radioactivity of the plants growing over the rhyolite porphyry was twice that of the plants growing over the sedimentary sequence, and plants growing in the zone of pitchblende mineralization were very radioactive. The plant analyses detected another possible pitchblende zone outside the known zone. At the Annie Laurie deposit the method provides an estimate of the amount of uranium mineralization to depths of about 20 feet, depending upon the species used.