Dawson Strait Group
"The Dawson Straits, located between eastern Fergusson and western Normanby Islands in the D'Entrecasteaux island group, contains a volcanic field with several volcanic centers that define a possible partly submerged caldera. There have been no historical eruptions from this center, but morphology suggests an extremely young age for some lava flows, and the area displays vigorous thermal activity. The most prominent volcanic centers are Mounts Lamonai and Oiau, located about 10 km apart on the SW tip of Fergusson Island. The 500-m-high summit of Lamonai is capped by a steep-walled crater, and rhyolitic lava flows are exposed on the NE side of the cone. Dominantly volcaniclastic Oiau cone has also produced obsidian lava flows. Dobu Island to the south is formed of coalescing volcanic centers and likewise has produced youthful rhyolitic obsidian flows."  -Smithsonian Volcano Archive
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