“…After original paleomagnetic studies on the Elkhorn Mountains Volcanics (Colville, 1961;Hanna, 1965Hanna, , 1967 were completed, two pieces of new information about the volcanic field that offered an opportunity to further the paleomagnetic understanding of the rocks were published. First, radiometric dates obtained for welded tuffs and breccias not previously sampled (Robinson and Marvin, 1967;Robinson and others, 1968) provided a firm time base for previous inferences about paleomagnetic field directions and polarities. Second, an aeromagnetic map covering parts of the Elkhorn Mountains volcanic field (Johnson and others, 1965) showed an anomalous zone of field values over basalts that occur within or near an extensive mining district, suggesting that the basalts have anomalous magnetizations.…”