Morphostructural analysis of Jamaica

Abstract

To Jamaica, macroblock in differential ascent in the plate boundary zone of the Caribbean—North America, a set of morphostructural and geological methods and procedures was applied that permitted its neostructure to be explained. It is composed of two mesoblocks, 11 blocks, 29 microblocks, and 65 nanoblocks. This group configures a heterogeneous network of morphoalignments and knots; knot N1 (Montego) and N11 (Kingston) being the most active. The main watershed was delimited, with an E-W strike, that reflects in its inflections the influence of a shear tectonic, mainly ancient, and that watershed divides the insular territory into two sectors (of rectangular figures) to the north and to the south. The river network is conditioned, in sectors and fundamentally, by tectonic factors. From a morphometric point of view the greater levels of uplifting (>1000 m) are located in the eastern part, in the Blue Mountains, though the estimated raising sectors denote that on its edges the recent intensity reaches values of ∼500 m. The contemporary faulting is more important in the marine parts of the north and of the south zones where the strongest earthquakes are located; however, this element is linked differently with the disruptive structures inherited, modified and active of the emerged part, those which determined that they are neither vast nor homogeneous. The seismic activity is justified by its space—time location in a transpression area of the plate boundary zone and where six relevant seismogenetic zones exist. In these elements the larger geological hazard is framed.