GRD00B3S0

I-427

Foid-Bearing Extrusive

Cenozoic › Paleogene › Eocene › Early Eocene › Ypresian
48.6 - 55.8

0

Ritter 154 › Cabinet 20 › Drawer I

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Pseudo-leucite phonolite. Emplaced between 54 to 50 Ma

GSA Bull 52: 1733 (1941)

Highwood Mtns

Montana
Highwood Mtn
Latitude: 47.46°
Longitude: -110.56°

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N/A

N/A

N/A

Larsen_GSABulletin_1941
Larsen, E.S. 1941. Igneous rocks of the Highwood Mountains, Montana; Part II, The extrusive rocks: Bulletin of the Geological Society of America, vol. 52, pg. 1733-1752.