Westgate, John A.; Preece, S. J.; Froese, Duane G.; Pearce, Nicholas J. G.; Roberts, R. G.; Demuro, M.; Hart, W. K.; Perkins, William T.
(2008-02)
Sheep Creek tephra (SCt) consists of inflated, rhyolitic pumice with abundant plagioclase and hornblende, lesser amounts of ferrian ilmenite and magnetite, and trace quantities of basaltic hornblende, augite, quartz, ...