Home
Volcanoes
Webcams
News
Explore Data
Images
Get Involved
About AVO

Sample: 74-ARh-310

Sample ID: 74-ARh-310 [1] [2]
Station ID: 74-ARh-310
AT Num:
Volcano: Drum
Possible source:
Eruption:
Collector: Richter, D. H.
Date sampled: 1974-00-00
Sample type 1: Lava
Color:
Final unit:
Text Description: Dacite flows of Snider Peak - Massive dark gray weathering hornblende-rich flows that radiate from general area of Snider Peak dome. Flows are as much as 100 m thick but appear to consist of complex multiple-flow cooling units suggesting possibility of more than one source, perhaps in part including second-cycle cone-building flows. They locally contain abundant concentrations of xenoliths and exhibit conspicuous columnar jointing. Rocks are light gray to pinkish medium gray with abundant medium (2-5 mm) phenocrysts of plagioclase and brown hornblende, minor to common hypersthene, and rare biotite, resorbed augite, and olivine generally in a feldspar-rich pilotaxitic to trachytic groundmass. Glassy phases have hyalopilitic and locally spherulitic groundmass textures. Chemistry: samples 23 (74-Amm-76B), 26 (74-Arh-310)
Sample Location:

References Cited

[1] Eruptive history and petrology of Mount Drum volcano, Wrangell Mountains, Alaska, 1994

Richter, D.H., Moll-Stalcup, E.J., Miller, T.P., Lanphere, M.A., Dalrymple, G.B., and Smith, R.L., 1994, Eruptive history and petrology of Mount Drum volcano, Wrangell Mountains, Alaska: Bulletin of Volcanology, v. 56, n. 1, p. 29-46.

[2] Geologic map of the Gulkana A-2 quadrangle, Alaska, 1979

Richter, D. H., Smith, R. L., Yehle, L. A., and Miller, T. P., 1979, Geologic map of the Gulkana A-2 quadrangle, Alaska: U.S. Geological Survey Geological Quadrangle Map GQ 1520, unpaged, 1 plate, scale 1:63,360.