A Miocene submarine volcano at Low Layton, Jamaica

A submarine fissure eruption of Upper Miocene age produced a modest volume of alkaline basalt at Low Layton, on the north coast of Jamaica. The eruption occurred in no more than a few hundred meters of water and produced a series of hyaloclastites, pillow breccias and pillow lavas, massive lavas, and dikes with an ENE en echelon structure. The volcano lies on the trend of one of the island's major E-W strike-slip fault zones; the Dunavale Fault Zone. The K-Ar age of the eruption of 9.5 plus or minus 0.5 Ma. B.P. corresponds to an extension of the Mid-Cayman Rise spreading center inferred from magnetic anomalies and bathymetry of the Cayman Trough to the north and west of Jamaica. The Low Layton eruption was part of the response of the strike-slip fault systems adjacent to this spreading center during this brief episode of tectonic readjustment.