Phrase ash fall deposit
- Within this volcanic arc, volcanic activity provided pyroclastic ash fall deposits to the area.
- Thirty-eight percent of the 1044 were found in the ash fall deposits, the majority inside buildings.
- Thirty-eight percent of the 1, 044 were found in the ash fall deposits, the majority inside buildings.
- This results in an ash fall deposit which generally decreases in thickness and grain size exponentially with increasing distance from the volcano.
- A 270, 000 ?80, 000 year old dacitic lava flow on Chachani's eastern flank is more likely to come from Chachani than El Misti, as are ash fall deposits found on top of this lava ( which is thus older ) and covering Chachani's flanks.
- The Santa Fe Group was deposited during the Miocene and Pliocene . This thick layer consists of the Hayner Ranch Formation ( conglomerate, sandstone and shale ), the Rincon Valley Formation ( conglomerate, sandstone, and mudstone ), the Selden basalts, and the Camp Rice / Palomas Formations ( ash fall deposits, basalts, and pumice-clast conglomerates ).