favoring algal growth, thus limiting the reestablishment of
reef framework. A few in situ framework dates are only
a few hundred years old, but this late period of growth is
believed to have succumbed to high turbidity and eutrophication following clearing for agriculture from the mid
1600s (Macintyre et al., 2007a, b). However, an alternative view has been put forward by Blanchon who believes
that hurricane emplacement of older clasts onto the crest
of modern reefs, is not valid evidence of the timing of reef
demise, which should be established from the age range of
in-place colonies from cores through the reef deposit
itself. There is the suggestion of a 500–400-year old reef
under at least a meter of storm deposit. Such a reef would
have grown to about 0.5 m below sea level when covered
by storm deposits about 300 years ago. As the reef crest is
now 2 m below sea-level, this would require the erosion of
$2.5 m of reef before the storm rubble was deposited. It is
possible that both interpretations can be accommodated
though not at the high energy Cobblers Reef site. Elsewhere on Barbados in more sheltered locations, reef
growth may have continued until European settlement
and clearance.
Hydrogeology (Humphrey, 1997)
The porous and permeable Pleistocene coral cap of Barbados permits ground water recharge where precipitation
exceeds evaporation in the higher parts of the island. The
Tertiary sediments of the Scotland District provide an
aquiclude that prevents downwards movement of water
and where this lies above sea level, groundwater flows
along the base of the limestones in underground streams.
However, towards the coast where the aquiclude lies
below sea level, a coastal phreatic freshwater wedge and
associated mixing zone are developed. Meteoric vadose,
meteoric phreatic and mixing zone waters interact with
the young subaerially exposed limestones, resulting in
a wide range of diagenetic modification. Barbados provides an excellent source of information for geohydrology
and diagenesis in uplifted coral reef environments.
Conclusion
Reef development in the uplifted and submerged reef terraces and their modern counterparts have yielded an
exceptional number of important scientific advances and
are a valuable resource that will ensure that Barbados continues to be a focal point for studies of both reefs and quaternary climate change. The past history of study and easy
accessibility are two factors that add to this value. Many
questions related to, for example, the detailed uplift history of the island still require answers, which may become
more precise with advances in dating techniques.
Bibliography
Bard, E., 1998. Geochemical and geophysical implications of the
radiocarbon calibration. Geochemica, Cosmochimica Acta, 62,
2025–2038.
Bard, E., Hamelin, B., Fairbanks, R. G., and Zindler, A., 1990. Calibration of the
14 C timescale over the past 30,000 years using
mass spectrometric U-Th ages from Barbados corals. Nature,
345, 405–410.
Bell, P. R. F., and Tomascik, T., 1993. The demise of the fringing
coral reefs of Barbados and of regions in the Great Barrier Reef
(GBR) lagoon-impacts of eutrophication. In Ginsburg, R. N.
(comp) Proceedings of the Colloquium on Global Aspects of
Coral Reefs: Health, Hazards and History. Rosenstiel School
of Marine and Atmospheric Science: University of Miami, Florida, pp. 319–325.
Bender, M. L., Fairbanks, R. G., Taylor, F. W., Matthews, R. K.,
Goddard, J. G., and Broecker, W. S., 1979. Uranium-series dating of the Pleistocene reef tracts of Barbados, West Indies. Geological Society of America Bulletin, 90, 577–594.
Blanchon, P., 2005. Comments on “Corrected Western Atlantic sealevel curve for the last 11,000 years based on calibrated
14 C dates
for Acropora palmata framework and intertidal mangrove peat
“by Toscano and Macintyre (Coral Reefs, 2003, 22: 257–270).
Coral Reefs, 24, 183–186.
Blanchon, P., and Eisenhauer, A., 2001. Multi-stage reef development on Barbados, during the Last Interglaciation. Quaternary
Science Reviews, 20, 1093–1112.
Blanchon, P., and Shaw, J., 1995. Reef drowning during the last
deglaciation: evidence for catastrophic sea-level rise and icesheet collapse. Geology, 23, 4–8.
Broecker, W. S., Thurber, D. L., Goddard, J., Ku, T.-L., Matthews,
R. K., and Mesolella, K. J., 1968. Milankovitch hypothesis
supported by precise dating of coral reefs and deep sea sediments. Science, 159, 297–300.
Edwards, R. L., Chen, J. H., and Wasserburg, G. J., 1987. 238U234U-230Th-232Th systematics and the precise measurement
of time over the past 500,000 years. Earth and Planetary Science
Letters, 81, 175–192.
Fairbanks, R. G., 1989. A 17,000-year long glacio-eustatic sea level
record: influence of glacial melting rates on the Younger Dryas
event and deep-ocean circulation. Nature, 342, 637–642.
Fairbanks, R. G., and Matthews, R. K., 1978. The marine oxygen
isotope record in Pleistocene coral, Barbados, West Indies. Quaternary Research, 10, 181–196.
Fairbanks, R. G., Mortlock, R. A., Chiu T. C., Cao, L., Kaplan, A.,
Guilderson, T. P., Fairbanks, T. W., Bloom, A. L., Grootes, P. M.,
and Nadeau, M. J., 2005. Radiocarbon calibration curve spanning 0 to 50,000 years BP based on paired Th-230/U-234/
U-238 and C-14 dates on pristine corals. Quaternary Science
Reviews, 24, 1781–1796.
Gallup, C. D., Cheng, H., Taylor, F. W., and Edwards, R. L., 2002.
Direct determination of the timing of sea level change during termination II. Science, 295, 310–313
Goreau, T. F., 1939. The ecology of Jamaican coral reefs. 1: Species
composition and zonation. Ecology, 40, 67–90
Gornitz, V., 2008. Sea level change, Post-Glacial. In Gornitz, V.
(ed.), Encyclopedia of Paleoclimatology and Ancient Environments, Encyclopedia of Earth Sciences Series. Dordrecht, The
Netherlands: Springer, 887–893.
Harrison, R. S., 1977. Caliche profiles: indicators of near surface
subaerial diagenesis, Barbados, West Indies. Bulletin of Canadian Petroleum Geology, 25, 123–223.
Hopley, D., 1982. Geomorphology of the Great Barrier Reef:
Quaternary Development of Coral Reefs. New York: Wiley,
453pp.
Humphrey, J. D., 1997. Geology and hydrogeology of Barbados. In
Vacher, H. I., and Quinn, T. (eds.), Geology and Hydrogeology of
Carbonate Islands. Developments in Sedimentology. Vol. 34,
381, 406.
Jackson, J. B. C., 1997. Reefs since Columbus. Coral Reefs, 16
(Suppl), S23–S32.
BARBADOS
101
reef framework. A few in situ framework dates are only
a few hundred years old, but this late period of growth is
believed to have succumbed to high turbidity and eutrophication following clearing for agriculture from the mid
1600s (Macintyre et al., 2007a, b). However, an alternative view has been put forward by Blanchon who believes
that hurricane emplacement of older clasts onto the crest
of modern reefs, is not valid evidence of the timing of reef
demise, which should be established from the age range of
in-place colonies from cores through the reef deposit
itself. There is the suggestion of a 500–400-year old reef
under at least a meter of storm deposit. Such a reef would
have grown to about 0.5 m below sea level when covered
by storm deposits about 300 years ago. As the reef crest is
now 2 m below sea-level, this would require the erosion of
$2.5 m of reef before the storm rubble was deposited. It is
possible that both interpretations can be accommodated
though not at the high energy Cobblers Reef site. Elsewhere on Barbados in more sheltered locations, reef
growth may have continued until European settlement
and clearance.
Hydrogeology (Humphrey, 1997)
The porous and permeable Pleistocene coral cap of Barbados permits ground water recharge where precipitation
exceeds evaporation in the higher parts of the island. The
Tertiary sediments of the Scotland District provide an
aquiclude that prevents downwards movement of water
and where this lies above sea level, groundwater flows
along the base of the limestones in underground streams.
However, towards the coast where the aquiclude lies
below sea level, a coastal phreatic freshwater wedge and
associated mixing zone are developed. Meteoric vadose,
meteoric phreatic and mixing zone waters interact with
the young subaerially exposed limestones, resulting in
a wide range of diagenetic modification. Barbados provides an excellent source of information for geohydrology
and diagenesis in uplifted coral reef environments.
Conclusion
Reef development in the uplifted and submerged reef terraces and their modern counterparts have yielded an
exceptional number of important scientific advances and
are a valuable resource that will ensure that Barbados continues to be a focal point for studies of both reefs and quaternary climate change. The past history of study and easy
accessibility are two factors that add to this value. Many
questions related to, for example, the detailed uplift history of the island still require answers, which may become
more precise with advances in dating techniques.
Bibliography
Bard, E., 1998. Geochemical and geophysical implications of the
radiocarbon calibration. Geochemica, Cosmochimica Acta, 62,
2025–2038.
Bard, E., Hamelin, B., Fairbanks, R. G., and Zindler, A., 1990. Calibration of the
14 C timescale over the past 30,000 years using
mass spectrometric U-Th ages from Barbados corals. Nature,
345, 405–410.
Bell, P. R. F., and Tomascik, T., 1993. The demise of the fringing
coral reefs of Barbados and of regions in the Great Barrier Reef
(GBR) lagoon-impacts of eutrophication. In Ginsburg, R. N.
(comp) Proceedings of the Colloquium on Global Aspects of
Coral Reefs: Health, Hazards and History. Rosenstiel School
of Marine and Atmospheric Science: University of Miami, Florida, pp. 319–325.
Bender, M. L., Fairbanks, R. G., Taylor, F. W., Matthews, R. K.,
Goddard, J. G., and Broecker, W. S., 1979. Uranium-series dating of the Pleistocene reef tracts of Barbados, West Indies. Geological Society of America Bulletin, 90, 577–594.
Blanchon, P., 2005. Comments on “Corrected Western Atlantic sealevel curve for the last 11,000 years based on calibrated
14 C dates
for Acropora palmata framework and intertidal mangrove peat
“by Toscano and Macintyre (Coral Reefs, 2003, 22: 257–270).
Coral Reefs, 24, 183–186.
Blanchon, P., and Eisenhauer, A., 2001. Multi-stage reef development on Barbados, during the Last Interglaciation. Quaternary
Science Reviews, 20, 1093–1112.
Blanchon, P., and Shaw, J., 1995. Reef drowning during the last
deglaciation: evidence for catastrophic sea-level rise and icesheet collapse. Geology, 23, 4–8.
Broecker, W. S., Thurber, D. L., Goddard, J., Ku, T.-L., Matthews,
R. K., and Mesolella, K. J., 1968. Milankovitch hypothesis
supported by precise dating of coral reefs and deep sea sediments. Science, 159, 297–300.
Edwards, R. L., Chen, J. H., and Wasserburg, G. J., 1987. 238U234U-230Th-232Th systematics and the precise measurement
of time over the past 500,000 years. Earth and Planetary Science
Letters, 81, 175–192.
Fairbanks, R. G., 1989. A 17,000-year long glacio-eustatic sea level
record: influence of glacial melting rates on the Younger Dryas
event and deep-ocean circulation. Nature, 342, 637–642.
Fairbanks, R. G., and Matthews, R. K., 1978. The marine oxygen
isotope record in Pleistocene coral, Barbados, West Indies. Quaternary Research, 10, 181–196.
Fairbanks, R. G., Mortlock, R. A., Chiu T. C., Cao, L., Kaplan, A.,
Guilderson, T. P., Fairbanks, T. W., Bloom, A. L., Grootes, P. M.,
and Nadeau, M. J., 2005. Radiocarbon calibration curve spanning 0 to 50,000 years BP based on paired Th-230/U-234/
U-238 and C-14 dates on pristine corals. Quaternary Science
Reviews, 24, 1781–1796.
Gallup, C. D., Cheng, H., Taylor, F. W., and Edwards, R. L., 2002.
Direct determination of the timing of sea level change during termination II. Science, 295, 310–313
Goreau, T. F., 1939. The ecology of Jamaican coral reefs. 1: Species
composition and zonation. Ecology, 40, 67–90
Gornitz, V., 2008. Sea level change, Post-Glacial. In Gornitz, V.
(ed.), Encyclopedia of Paleoclimatology and Ancient Environments, Encyclopedia of Earth Sciences Series. Dordrecht, The
Netherlands: Springer, 887–893.
Harrison, R. S., 1977. Caliche profiles: indicators of near surface
subaerial diagenesis, Barbados, West Indies. Bulletin of Canadian Petroleum Geology, 25, 123–223.
Hopley, D., 1982. Geomorphology of the Great Barrier Reef:
Quaternary Development of Coral Reefs. New York: Wiley,
453pp.
Humphrey, J. D., 1997. Geology and hydrogeology of Barbados. In
Vacher, H. I., and Quinn, T. (eds.), Geology and Hydrogeology of
Carbonate Islands. Developments in Sedimentology. Vol. 34,
381, 406.
Jackson, J. B. C., 1997. Reefs since Columbus. Coral Reefs, 16
(Suppl), S23–S32.
BARBADOS
101