← Search

Sample 82-504

NavDat sample number 36173 · RHYOLITE

Sample

Sample ID82-504
Rock nameRHYOLITE
Rock typeVOLCANIC
CompositionFELSIC
MaterialIGNEOUS
Commentscattered phenocrysts of K-feldspar and quartz along with rare hornblende and magnetite in glassy matrix which is partly devitrified; flow banding present; the rhyolite forms a tabular to dome-shaped mass on Archean gneiss and at base of basaltic-andesitic lava flow sequence of the Challis Volcanic Group in the NW part of Medicine Lodge basin

Location

Latitude44.9539
Longitude-113.254
State / provinceMontana
Volcanic fieldChallis Volcanic Group

Age

Age (Ma)ErrorMinMaxGeologic ageDated by
48.69 48.51 48.87

Analyses

No chemical analyses are stored for this sample.

References