Record Details
Field | Value |
---|---|
Title | Elemental abundances in selected Oregon basalts |
Names |
Nicholson, Barry Howard
(creator) Schmitt, Roman A. (advisor) |
Date Issued | 1970-08-11 (iso8601) |
Note | Graduation date: 1971 |
Abstract | Ninety basalt samples from eight locations in central Oregon and one location in the Willamette Valley were analyzed for Si and Al. Fourteen basaltic rock specimens (> 1 kg each) from four buttes in the Willamette Valley were sampled and analyzed for Si, Al, Fe, Na, K, Mn, Cr, Co, Sc, and La. All analyses were carried out via instrumental neutron activation analysis to precisions of about 15% for K, 20% for La, 40% for Cr, and about 2-4% for the remaining elements. The average abundances of all locations were compared with the average abundances of Picture Gorge, Yakima, and Late Yakima basalts, the three subtypes of Columbia River basalt. The five Willamette Valley averages were also compared with those of normal continental tholeiites and the Siletz River tholeiites and alkalic basalts. The Si abundance averages for Emigrant Creek, Highway 27, Madras, Bond Butte, and Coburg Quarry locations were found to match within limits those of Picture Gorge basalt. The Al averages were somewhat lower than in Picture Gorge for the Madras site and somewhat higher for the remaining four sites. The average values obtained for the lower six Klickitat River flows were found to agree with average values for Yakima basalt. Abundance averages of Locke Lake, Rock Creek Canyon, the upper nine Klickitat River flows, Hay Creek Canyon, Hale Butte, and Knox Butte were all found to agree within limits with average values of Late Yakima basalt. From the field relations, the basalts from Hay Creek Canyon are believed to be of Yakima type. The individual abundances obtained from the Locke Lake and Rock Creek sites suggest that four of the flows from each site may be laterally equivalent with each other. The abundance averages for Saddle Butte suggest that the flows which make it up are probably not related to Columbia River basalt. No significant relationship between any of the Willamette Valley sites and the Siletz River tholeiitic or alkalic basalts was established, except for Hale Butte, whose average abundances appear to fit into the abundance ranges for the Siletz River alkalics. |
Genre | Thesis/Dissertation |
Topic | Geochemistry |
Identifier | http://hdl.handle.net/1957/45565 |