| | Book | to Lower Miocene John Day Formation in central Oregon (Hay, 1963a), The ash was wind-lain and reworked...containing fresh glass, montmorillonite clay, and opal; a transition zone (up to 20 mOl thick) composed...(up to 12 meters thick) that contains fresh glass, opal, and montmorillonite; a middle zone (up to 10 meters...deposits of the John Day Formation, in central Oregon. The zeolites in the tuff deposits formed from...assemblages have been mapped in exposed basaltic rock in County Antrim, Northern Ireland, and eastern Iceland. | | | Book | to Lower Miocene John Day Formation in central Oregon (Hay, 1963a), The ash was wind-lain and reworked...containing fresh glass, montmorillonite clay, and opal; a transition zone (up to 20 mOl thick) composed...(up to 12 meters thick) that contains fresh glass, opal, and montmorillonite; a middle zone (up to 10 meters...deposits of the John Day Formation, in central Oregon. The zeolites in the tuff deposits formed from...assemblages have been mapped in exposed basaltic rock in County Antrim, Northern Ireland, and eastern Iceland. |
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