|
Pre-Caldera Volcanics
|
The original shield volcano was
built by lava flows.
|
|
Sequence 1
|
This sequence is 60 m thick. It fills
topographic depressions on the basal shield volcano.
1) Coarse ash and medium lapilli
(50%).
2) Pumice (15%).
3) Cauliflower bombs and glassy clasts
(15%)
4) Basaltic accidental clasts (20%) |
|
Sequence 2
|
This sequence is 200 m thick.
1) Thin coarse ash with glass fragments
and accretionary lapilli.
2) Agglomerates of vitric clasts
and shards. |
|
Sequence 3
|
This sequence is 10-25 m thick. It
consists of ash flow deposits almost free of xenoliths. |
|
Sequence 4
|
This sequence is up to 250 m thick.
It consists of emissions from the Woosantapalipplip vent. |
|
Post-Caldera Volcanics
|
These are the eruptions during the
past 2000 years. |
