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Petrology And Geochemistry Of Mafic Lavas Near Glacier Peak, North Cascades, Washington, Dylan D. (Dylan Douglas) Taylor

WWU Graduate School Collection

Major element, trace element, and mineral compositions have been determined for four Quaternary mafic monogenetic cinder cones and flows south of Glacier Peak, a dacitic stratovolcano in the northern Cascade arc. The flows are the Whitechuck basalt, and the basaltic andesites of Indian Pass, Lightning Creek, and Dishpan Gap. Whitechuck has high concentrations of AI₂O₃ (≥ 18 wt.%) and low concentrations of K₂O (≤ 0.45 wt.%) and shares similar trace element characteristics with high alumina olivine tholeiites reported in the central and southern Cascades. The three basaltic andesites are calc-alkaline. Indian Pass and Lighting Creek …