Bahamas

Imported Inorganic Chemical Elements, Oxides and Halogen Salts in Bahamas, 2002 

Country of Origin Rank Value (000 US ) % Share Cumulative % 

Source Philip M. PARKER, Professor, INSEAD, copyright 2002, www.icongrouponline.com 

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Bioluminescence functions in mating (fireflies, the Bahama fireworm), in the search for prey (angler fish, Photmus fireflies), camouflage (hatchet fish, squid), schooling (euphausiid shrimp), and to aid deep water fish (flashlight fish, Photoblepharon to see in the dark ocean depths. 

Aragonite. Calcium carbonate is a common deposit in shallow tropical waters as a constituent of muds, or in the upper part of coral reefs where it precipitates from carbon dioxide-rich waters supersaturated with carbonate from intense biological photosynthesis and solar heating. Deposits of ooHtic aragonite, CaCO, extending over 250,000 km in water less than 5 m deep ate mined for industrial purposes in the Bahamas for export to the United States (19). 

Mazadan). Offshore sites are 0> Morton (Inagua, Bahamas), and Akzo Nobel (Bonaire, Nethedands Antilles). Courtesy of the Salt Institute. 

Some of the magie Students and teaeher view a eoral erab in Graham s Harbour, San Salvador Island, the Bahamas. (Lara Call)... 

Robinson LF, Henderson GM, Slowey NC (2002) U-Th dating of marine isotope stage 7 in Bahamas slope sediments. Earth Planet Sci Lett 196 175-187... 

However, the Slowey et al. (1995) work on shallower carbonate bank sediments (off of the Bahamas) was successful and led to the dating of a number of important events in the marine oxygen isotope record (including the timing of the Last Interglacial (Slowey et al. 1996), Termination II (Henderson and Slowey 2000) and portions of the Penultimate Interglacial (Slowey et al. 1996, Robinson et al. 2002). The shallower depths obviate the most serious of the initial thorium problems encountered in the Nicaragua Rise work. 

Chen JH, Curran HA, White B, Wasserbmg GJ (1991) Precise chronology of the last interglacial period 238 j/23o-pjj fossil coral reefs in the Bahamas. Geol Soc Amer Bull 103 82-97... 

Richards DA (1995) Pleistocene sea levels and paleoclimate of the Bahamas based on Th-230 ages of speleothems. PhD Dissertation. University of Bristol, Bristol, United Kingdom Richards DA, Smart PL, Edwards RL (1994) Maximtrm sea levels for the last glacial period from U-series ages of submerged speleothems. Nature 367 357-360... 

Slowey NC, Henderson GM, Curry WB (1995) Direct dating of the last two sea-level highstands by measurements of U/Th in marine sediments from the Bahamas. EOS 76(46) 296-297 Slowey NC, Henderson GM, Curry WB (1996) Direct U-Th dating of marine sediments from the two most recent interglacial periods. Nature 383 242-244... 

Figure 5. U and Th isotope measurements for 9 coeval sets of sub-samples from GB-89-24-1, Grand Bahama (Beck et al. 2001) are plotted in (A) (230Th/232Th)A-( U/2 Th)A and (B)...

The most susceptible material for post-depositional loss or addition of radionuclides is the outer layer of samples that have been exposed to moisture for a long duration. Stratigraphic consistency between ages of the outermost material and that deposited prior to this provides valuable constraints on the technique. Four ages were derived for a band of clear, white calcite deposited on a stalactite from 53.6 m below sea level in a blue hole of Andros, Bahamas (Richards et al. 1994). Isotopic data for the outermost surface, which had been exposed to sea water for at least 8 ka was indistinguishable from the internal material (Fig. 8). 

Figure 8. TIMS ages of latest phase of growth of GB-89-23-2 (Richards et al. 1994). Outermost sample (ABTl n = 4) indistinguishable from ages of older material up to 10 mm inside outer surface of this stalactite. GB-89-23-2 was collected from a depth of 53.6 m below present sea level in Stargate, Andros, Bahamas, and was submerged since inundation by rising sea levels during the last deglaciation.

Figure 20. Secular variation in 5 U(0) for Bahamas flowstone sequence. Changes in 5 U(0) are related to uranium-series disequilibrium conditions in host limestone, periodic addition of new material with elevated (marine) 5 U(0), alpha recoil effects and variation in recharge, and hence water-rock interaction times (see text for details).

Gascoyne M, Benjamin GJ, Schwarcz HP, Ford DC (1979) Sea-level lowering during the Illinoian glaciation evidence from a Bahama "Blue Hole. Science 205 806-808 Gascoyne M, Currant AP, Lord TC (1981) Ipswichian fauna of Victoria Cave and the marine palaeoclimatic record. Nature 294 652-4... 

Roberts MS, Smart PL, Hawkesworth CJ, Perkins WT, Pearee NJP (1999). Trace element variations in coeval Holocene speleothems from GB Cave, southwest England. The Holocene 9 138-139 Robinson LF, Henderson GM, Slowey NC (2002) U-Th dating of marine isotope stage 7 in Bahamas slope sediments. Earth Planet Sci Lett 196 175-187... 

Smith PE, Farquhar RM Hancock RG (1991) Direct radiometric age determination of carbonate diagenesis using U-Pb in secondary calcite. Earth Planet Sci Lett 105 474-491 Spalding RF, Mathews TD (1972) Submerged stalagmites from caves in the Bahamas Indicators of low sea level stand. Quat Res 2 470-472... 

Henderson GM, Lindsay FN, Slowey NC (1999) Variation in bioturbation with water depth on marine slopes a study on the Little Bahamas Bank. Mar Geol 160 105-118 Henderson GM, Anderson RF (2003) The U-series toolbox for paleoceanography. Rev Mineral Geochem 52 493-531... 

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