Cockpit Country comprises much of the Troy-Claremont Limestone Formation, the oldest layer of the White Limestone Group that was laid down on the Yellow Limestone Group during the mid Eocene age. The Troy Limestone consists of well-bedded to massive yellow-brown to pink recrystallized limestones and dolomites that are generally unfossiliferous. The Claremont Formation consists of evenly-bedded, bioclastic, mollusc-rich limestones. The low-lying areas and flanks of the Cockpit Country are floored by alluvial clay, derived from the weathering of limestone.
The Cockpit Country area shows an overall regional dip of 5deg to 15deg to the NNW, with the exception of the structurally complex Duanvale Fault system where there is evidence of folding along E-W to ENE trending axes. This folding has brought the Yellow Limestone Group in the Sherwood Content Area to the surface. Faulting in the Cockpit area is generally along N-S lines and is viewed easily in aerial photographs or on-the-ground along the Barbecue Bottom/Burnt Hill Road.
Nearly two-thirds of Jamaica is covered by the White Limestone Group. Chemical dissolution of limestone bedrock (karstification) creates landforms with characteristic features:
On Jamaica, the karstification of the White and Yellow Limestone Groups, which vary considerably in quality (e.g., purity, hardness) and depth, has resulted in a landscape varying from gently rolling, soil-covered plains through rough and jumbled deep depressions, isolated towers, and pointed hills. The Cockpit Country represents the most well-developed cockpit or polygonal karst and, indeed, is recognized globally as the type locality for this pattern of above-ground karst landform (White 1988). Cockpit karst comprises steep-sided, bowl-shaped closed depressions separated by roughly conical peaks. The depressions have concave floors covered with a variable amount of rock rubble and soil while the hilltops and slopes are marked by a distinctively minimal clay soil and organic humus. Cockpits average in depth from 100 - 120m and walls generally slope from 30 to 40 degrees. Drainage of the cockpit bottoms occurs via percolation or by sinkhole. Drainage by the latter creates a complex, subterranean cellular network. The periphery of Cockpit Country is marked by 'degraded' cockpits, glades and interior valleys (poljes), such as seen in the Windsor, Pantrepant, and Fontabelle areas, terminating to the west in the Queen of Spain's Valley, the best known and largest polje in Jamaica. Tower karst is found to the north in the Duanvale Fault zone as well as in the southeast region.
Subterranean cave formation is a distinctive feature associated with karst terrain. These voids form along weak lines in the limestone rock, carved out by percolating rainwater and groundwater. At present, over 1,200 caves, passages and sinkholes have been registered for Jamaica (Fincham 1997). Per square kilometer, Jamaica has among the highest number of caves of any country in the world. Minimally, 270 caves are located within the region of the Cockpit Country and almost all are or can be used as habitats for a great variety of wildlife, including "troglobites" (found only in caves and demonstrating adaptations for life in a world of darkness [e.g., loss of pigment, partial or total reduction of eyes]), "troglophiles" (found in both cave and noncave habitats) and "trogloxenes" (caves are required for part of the species' life cycle). While the mapping of Jamaica's caves is extensive, biospeleologic research has been conducted in less than 5% of caves (Peck 1992) and undoubtedly many species remain to be discovered.
Geologically the area details the formation of Jamaica, as seen from the western edge of the Central Inlier, the Yellow and White Limestone Groups, and the alluvial deposits in Barbecue Bottom and the Windsor Estate. The limestone of the Claremont Formation represents a fossil record of the highly diversified and long-extinct marine organisms that dominated the Cretaceous Period 100-65 million years ago. Large rudistid molluscs, some exceeding 2.5m can be seen preserved throughout the Inliers. The demise of these coral-like molluscs, distant relatives of present-day clams, occurred during the same period as the extinction of dinosaurs.
Soils
The White Limestone of the Cockpit Country has an incomplete cover of red bauxite soil, believed to have originated from dissolved volcanic ash laid down in the Miocene limestones (Draper and Fincham 1997). The soils are mostly categories HL4 and HL5. HL4 soils (also known as Ferraic Cambisols or Terra Rossa soils) are somewhat excessively drained, predominantly shallow, brown to reddish brown, loamy and clayey, stony, in places with many rock outcrops. They are high in iron and aluminium and silica. HL5 soils (also known as ferric cambisols and chromic vertisols or rendzinas) are moderately well drained, moderately deep, brown cracking clay soils. The tops of the cockpits are noted generally for their thin soils and organic humus. Slopes are predominantly bare rock and talus, while deep soils are restricted to the cockpit bottoms. The majority of the Cockpit Country is classified by the Government of Jamaica as "not suitable for cultivation because of soil and slope conditions and should remain in its natural vegetation" (National Atlas of Jamaica 1971)
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