155 Analyses

The Geology of Crater Lake National Park, Oregon With a reconnaissance of the Cascade Range southward to Mount Shasta by Howell Williams

Microscopic Petrography

 

Analyses

Analyses of Olivine-Bearing Pre-Mazama Lavas

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1. Olivine basalt, Santiam type (intracanyon flow). Near summit Outerson Mountain. Anal. R. B. Ellestad. T. P. Thayer, “Petrology of later Tertiary and Quaternary rocks of the north-central Cascade Mountains in Oregon,” Bull. Geol. Soc. Amer., vol. 48, p. 1622, 1937.

2. Olivine micronorite. Hunts Cove. Anal. R. B. Ellestad. Thayer, ibid.

3. Cristobalite micronorite, coarse facies of Minto plug. Anal. R. B. Ellestad. Thayer, ibid.

4. Olivine basalt. North base of Union Peak, quarry adjacent to Medford highway. Anal. W. H, Herdsman.

5. Olivine basaltic andesite. Red Blanket Canyon, near south base of Union Peak volcano. Anal. W. H. Herdsman.

6. Olivine micronorite, pale, coarse facies of Union Peak plug. Anal. W. H. Herdsman.

7. Hypersthene-bearing basaltic andesite. Annie Creek, near east base of Union Peak volcano. Anal. H. N. Stokes. J. S. Diller and H. B. Patton, “The geology and petrography of Crater Lake National Park,” U. S. Geol. Surv. Prof. Paper 3, p. 161, 1902.

8. Hypersthene-bearing basaltic andesite. Desert Ridge. &l. H. N. Stokes. Diller and Patton, ibid.

NOTE: Nos. 1, 2, and 3 are not Crater Lake rocks.

 

Analyses of Lavas Related to Cinder Cones

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9. Hypersthene-bearing olivine basalt. Southeast base of Red Cone. May be a pre-Mazama flow. Anal. H. N. Stokes. Diller and Patton, loc. cit.

10. Basaltic andesite, near summit of Crater Peak. Anal. W. H. Herdsman.

11. Olivine-bearing basaltic andesite. Main flow from west base of Forgotten Crater. Anal. W. H. Herdsman.

12. Olivine-bearing basaltic andesite. Southwest base of Timber Crater. Anal. W. H. Herdsman.

13. Hypersthene andesite. West edge of Wizard Island. Anal. H. N. Stokes. Diller and Patton, 09. cit., p. 94.