Lithostratigraphy and palaeogeography of the White Limestone Group

The White Limestone Group of Jamaica is divided into six formations. The Troy, Swanswick, Somerset and Moneague formations were deposited on a carbonate platform that developed on the stable Clarendon Block; the Montpelier and Pelleu Island formations were deposited in the deep-water troughs adjacent to this platform. The formations are characterised by the following lithologies: Troy – grey and pink, micritic limestones, dolomicrites and sucrose-dolostones; Swanswick – white, foraminiferal grainstones; Somerset – grey and pink, foraminiferal and algal packstones; Moneague – white grainstones, packstones and wackestones; Montpelier – chalks with chert bands; Pelleu Island – chalks lacking chert bands. The Ipswich Formation is transferred to the Yellow Limestone Group. In the late Middle Eocene, the Clarendon Block had a rim of foraminiferal grainstones surrounding a restricted, tidal-flat dominated platform. In the Late Eocene the platform was flooded to greater depth and packstones spread across the northern half. In the Oligocene, the platform margin was occupied by a grainy Lepidocyclina-dominated marginal facies that passed inward into a restricted marine interior with diverse assemblages of miliolid foraminifera. Similar facies patterns persisted into the Miocene, although any White Limestone of this age that was deposited has been eroded from the northern half of the platform. During the late Middle Eocene to Middle Miocene, in the deep-water troughs adjacent to the platform, chalks accumulated together with coarse-grained detritus (calcarenitic turbidites and calciruditic debris flows) derived from the shallow-water limestones of the Clarendon Block.