The volcanic rocks of the Harney Basin comprise a bimodal
assemblage of rhyolites (SiO₂ greater than 72%) and basalts (SiO₂
less than 52%). Tholeiitic basalts account for 15 rocks analyzed and
alkalic basalts for three. Most basalts contain phenocrysts of olivine
and plagioclase. Pyroxene phenocrysts were not found. Rhyolite
flows...
The volcanic rocks of the Harney Basin comprise a bimodal
assemblage of rhyolites (SiO₂ greater than 72%) and basalts (SiO₂
less than 52%). Tholeiitic basalts account for 15 rocks analyzed and
alkalic basalts for three. Most basalts contain phenocrysts of olivine
and plagioclase. Pyroxene phenocrysts were not found. Rhyolite
flows...
The volcanic rocks of the Harney Basin comprise a bimodal
assemblage of rhyolites (SiO₂ greater than 72%) and basalts (SiO₂
less than 52%). Tholeiitic basalts account for 15 rocks analyzed and
alkalic basalts for three. Most basalts contain phenocrysts of olivine
and plagioclase. Pyroxene phenocrysts were not found. Rhyolite
flows...