Volcanology of Saba and St. Eustatius, Northern Lesser Antilles
Submitted by Peter Verweij on Mon, 04/27/2015 - 23:03The two small islands of Saba and St. Eustatius (Netherlands Antilles) lie on the northernmost subaerial end of the active arc of the Lesser Antilles. They are separated by the 28 km wide St. Eustatius Passage, and 20 km further along the arc the submarine Lumeyes Bank represents the northernmost volcanic center of the arc. Saba with an area of 13 sq. km rises to the single peak of Mt. Scenery at 877 m above sea level. The island is essentially a complex of andesitic Pelean domes with surrounding aprons of pyroclastic material.
In contrast, the island of St. Eustatius lies at the north end of a continuous submarine bank that also contains the islands of St. Kitts and Nevis. The island has an area of 21 sq. km and is morphologically dominated by two volcanic centers. At the northern end the extinct Northern Centers rise 289 m a.s.l. and were once a separate island surrounded by sea cliffs. Two and a half kilometers to the southeast the morphologically youthful Quill volcano, with an 800 m diameter open crater, rises to 600
m a.s.l. A third volcanic succession is exposed in the White Wall-Sugar Loaf tilted limestone succession, which forms the southern shoreline of the Quill. The Northern Centers comprise five morphologically distinct coalesced volcanoes, the most youthful of which is the Pisgah Hill-Little Mountain-Bergje Dome complex with a crater 880 m in diameter which contains the youthful Bergje dome. The Northern Centers comprises intercalated pyroclastic deposits (derived from Pelean activity) and lava flows.
Retrieved from Saba Conservation Foundation
