Alkali basalt from the Pribilof Islands has been described by several workers (Washington and Keyes, 1930; Barth, 1956; Cox and others, 1966; and Kay, 1977). This report complements the previous reports by providing new petrographic and geochemical data for samples from St. Paul and St. George Islands and from two dredge hauls near St. George Island (Fig. 1).
The geologic setting of the Pribilof Islands region is given by Barth (1956), Hopkins and Einarsson (1965), Cox and others (1966), Hopkins and others (1969), Marlow and others (1976), and Hopkins and Silberman (1978). Quaternary basalt (Table 1) (Cox and others, 1966; Hopkins, 1976; Simpson and others, 1979) is extruded onto the structurally high Pribilof Ridge (Marlow and others, 1976) which consists of rocks as old as late Jurassic (Vallier and others, 1979). Barth (1956) recognized the structural implication of alkalic volcanism in back-arc environments. We plan to interpret alkalic volcanism in the Pribilof Islands within the context of recent tectonic and petrologic findings in the southern Bering Sea.
Funds for this project were provided jointly by the U.S. Geological Survey and Bureau of Land Management. Funds from the Bureau of Land Management were managed by the Outer Continental Shelf Environmental Assessment Program (OCSEAP) office of the National Oceanic and Atmospheric Administration (NOAA).
