stripes
Occurrence number:
174-00-045
Country:
United States
Region:
Oregon
Location:
Longitude: -119.38, Latitude: 43.13
Carbonatite:
No
Extensive Pliocene, peralkaline ash-flow tuff deposits in southeastern Oregon may have vented from the Buzzard Creek area which lies in a complex northwest-trending graben. The tuff sheet is zoned but appears to be a single flow. The rock contains phenocrysts of sanidine, quartz, aegirine-augite, plagioclase and less abundant magnetite, a colourless to light amber clinopyroxene and oxyhornblende. Textures and structures exhibited by the flow are described in detail by Walker (1969).
Age:
Pliocene.
References:
WALKER, G.W. 1969. Possible fissure vent for a Pliocene ash-flow tuff, Buzzard Creek area, Harney County, Oregon. Professional Paper, United States Geological Survey, 650-C: 8-17
Location: