Event Name : Amak older volcanics
|Start: 5000 || Years BP Tephrochronology || |
|Stop: 4000 || Years BP Tephrochronology || |Description:
|Eruption Product: || andesite ||
From Wood and Kienle (1990): "The earlier volcanism, perhaps some 4,000-5,000 yr ago, consisted mostly of thin (~3 m) platy to massive andesite."
From Marsh and Leitz (1978): "The older series of flows built a low-lying conical volcano with a summit crater about 300 m in diameter. These flows are predominantly massive to platy, grayish-black, but sometimes slightly dark pink, two-pyroxene andesites. They show no sign of brecciation. On the southwest side of the island a small U-shaped valley cut into the older series indicates local glaciation."
"According to Funlc (1973) the latest period of glaciation in this area was about 6,700 years B.P. The small U-shaped glacial valley cut into the older series was probably excavated during this period of glaciation. The older flows also show no sign of being extruded beneath ice. Thus Amak is probably not much older than 6,700 years."