St. Andrew Strait (Papua New Guinea)

Status Unknown Eruption 1957 270m
Complex (Subduction zone / Oceanic crust (< 15 km))

The St. Andrew Strait volcano, located in the Admiralty Islands north of Papua New Guinea, consists of a series of overlapping Quaternary cones formed by rhyolitic lava flows and pyroclastic materials on Lou and Tuluman Islands. Volcanism is aligned on a curved arc extending through the 12-km-long Lou Island, which may represent an incipient caldera ring fracture. The historically active Tuluman Islands, 1.5 km south of Lou Island, were formed during a 1953-1957 eruption. Pam Lin and Pam Mandian Islands farther to the SE along the same arc contain fresh rhyolitic obsidian similar to that found on Tuluman.

The St. Andrew Strait volcano is located in the Admiralty Islands north of Papua New Guinea. The volcanic complex consists of a series of overlapping Quaternary cones formed by rhyolitic lava flows and pyroclastic deposits on Lou and Tuluman Islands. Volcanism is aligned along a curved arc, extending through the 12-km-long Lou Island, which may represent an incipient caldera ring fracture. Tuluman Island, seen here from the SW with Lou Island 1.5 km away at the upper left, was formed during a 1953-1957 eruption.

Photo by Wally Johnson, 1964 (Australia Bureau of Mineral Resources).

Last updated 2019-08-04 00:28:02