Bahamas

Small Marina in the BahamasThe Bahamas are a unique recorder of global change. Their rapidly accumulating sediments span a wide range of water depths right in the core of the deep western boundary current of the North Atlantic. The sediment is dominated by carbonates, in which many geochemical tracers can be measured in order to reconstruct the past environment. And this carbonate is itself dominated by aragonite which has a very high U content making it datable with U/Th techniques. The sediments are also isolated from the continents by the Gulf Stream, which sweeps up the narrow Straits of Florida, so that they are not contaminated by continental detritus.



Coral Reef in the BahamasWe make extensive use of the sediment from this unique environment for our research into the past environment. Some of this work is performed on core material to investigate past marine change. Other research requires collection of modern samples to develop and refine geochemical proxies, and to investigate the terrestrial geology of the area. Modern samples are collected in several ways: water samples are collected from ships; shallow sediments and marine organisms such as corals are collected from small boats or by snorkelling; and terrestrial samples are collected by hitting them with a hammer.



The upper photo shows the Caribbean Marine Research Centre on Lee Stocking Island - a good base to conduct research. The middle picture shows an Acropora palmata reef. This species of coral only grows in very shallow water which makes it a particularly good recorder of sealevel. In the final picture, Caedmon gets a bit confused about relative sealevel while looking at a fossilised carbonate dune deposit.