From Wikipedia
About 700 thousand years ago, the island emerged from the ocean as a result of a rising body of soft rock in the mantle known as a diapir, located under Barbados, pushing it upwards. This process is still happening, and makes the island rise about 30 centimeters on average every thousand years. Currently, dozens of inland sea reefs still dominate coastal features within terraces and cliffs of the island.
Barbados lies on the boundary of the South American and the Caribbean Plates. The subduction of the South American plate beneath the Caribbean plate scrapes sediment from the South American plate and deposits it above the subduction zone forming an accretionary prism. The rate of this depositing of material allows Barbados to rise at a rate of about 25 mm (1 in) per 1,000 years. This subduction means geologically the island is composed of coral roughly 90 m (300 ft) thick, where reefs formed above the sediment. The land slopes in a series of “terraces” in the west and goes into an incline in the east. A large proportion of the island is circled by coral reefs.
The erosion of limestone in the northeast of the island, in the Scotland District, has resulted in the formation of various caves and gullies. On the Atlantic east coast of the island coastal landforms, including stacks, have been created due to the limestone composition of the area. Also notable in the island is the rocky cape known as Pico Teneriffe or Pico de Tenerife, which is named after the fact that the island of Tenerife in Spain is the first land east of Barbados according to the belief of the locals
| From Environmental Sensitivity Index Map of the Island of Barbados UNEP 2011, 43 pages. Posted on website for the Environmental Protection Department of Barbados:
“Barbados is geologically distinct from the majority of the Caribbean Islands which are volcanic in origin. The island’s origin is tectonic in nature and its geology is formed mainly by limestone originating from coral reefs. The terraces which characterise much of Barbados are underlain by fossil coral reefs. The limestone of these terraces was deposited around the margins of the island as it emerged from the sea during the later part of the Pleistocene epoch (about the last 900, 000 years). Tectonic uplift has been more or less continual through this time resulting in uplift of the older terraces to over 300 meters above sea level. The older, higher reef terraces have been exposed above sea level the longest and show substantially greater erosion than lower ones. “The terraces are covered by 0.6 to 1.0 meter of soil resulting from limestone erosion, volcanic ash from St. Vincent and subaerial debris transported from the Sahara by trade winds. “Coral reef terraces form a cap only about 100 meters thick over older non-reef sediments. The coral cap has been eroded away in the east of the island, the area known as the Scotland District which stretches along the coast from Gays Cove to Conset Bay. The exposed sediments below are up to 50 million years old, comprising sandstones, oil and gas-generating mudstones, and chalks interbedded with volcanic ash. “Other outcrops of Scotland deposits occur along the coastline at Cluffs (in St. Lucy), and at Skeetes Bay and Ragged Point (in St. Philip). “Today, the island is still fringed by a coral reef system which is in many respects is similar to the older reef terraces. This modern day system is characterised by fringing reefs, patch reefs, and offshore reefs. Water depth increases rapidly across the shelf, being 200 meters deep 2.5 km from shore (656 feet deep 1.5 miles from shore).” |
Late Pleistocene reef limestones, Northern Barbados, W.I.
Noel P. James, 1971. PhD thesis, Department of Earth and Planetary Sciences McGill University Also view on this wesbsite: NP James on the Uplifted Reefs of Barbados
Ecological persistence interrupted in Caribbean coral reefs
John M. Pandolfi &Jeremy B.C. Jackson 2006 in Ecology Letters. The recent mass mortality of Caribbean reef corals dramatically altered reef community structure and begs the question of the past stability and persistence of coral assemblages before human disturbance began. We report within habitat stability in coral community composition in the Pleistocene fossil record of Barbados for at least 95 000 years despite marked variability in global sea level and climate. Results were consistent for surveys of both common and rare taxa. Comparison of Pleistocene and modern community structure shows that Recent human impacts have changed coral community structure in ways not observed in the preceding 220 000 years.
Zonation of uplifted pleistocene coral reefs on Barbados, West Indies
Mesolella KJ. Science. 1967 May 5;156(3775):638-40.
Abstract: The coral species composition of uplifted Pleistocene reefs on Barbados is very similar to Recent West Indian reefs. Acropora palmata, Acropora cervicornis, and Montastrea annularis are qtuantitatively the most important of the coral species.
Late Quaternary folding of coral reef terraces, Barbados
Frederick W. Taylor and Paul Mann
Geology 1991;19;103-106
“Coral reefs on Barbados range in age and elevation from ca. 1 Ma terrace at an elevation of about 330 m along the southern edge of the Scotland District to the living fringing reef slightly below sea level…Each step of the staircase of reef terraces on Barbados formed as a level surface during relatively short periods of reef growth at major Quaternary highstands of sea level. Reefs formed during lowstands or periods of rapidly changing sea level are buried by highstand reefs. Bender et al. (1979) hâve defined 23 morphostratigraphic units that represent coral reef deposits associated with —14 discrete sea-level highstands.
“The two most prominent terraces of Barbados are First and Second High Cliff (Fig. 3). First High Cliff extends for about 60 km, has up to 25 m of topographic relief, and is predominately a constructional reef terrace built during the last interglacial, between about 122 aiid 130 ka (Edwards et al., 1987). The morphostratigraphic reef forming First High Cliff was informally designated as Rendezvous Hill by Bender et al. (1979). Less well developed reef terraces that rëeord less prominent highstands of sea level at ca. 82 and 105 ka crop out between First High Cliff and the present coastline (Mesolella et al., 1970).
“Second High Cliff is mappable for about 40 km and has up to 35 m of topographic relief, tut it is less continuous than First High Cliff. Its morphology has been modified by sea-level marine erosion during subséquent highstands. Isotopic ages from corals from Second High Cliff differ by about 100 ka (Bender et al., 1979).”
An early Holocene reef in the western Atlantic: submersible investigations of a deep relict reef off the west coast of Barbados, W.I.
I. G. Macintyre et al., 1990. Coral Reefs volume 10, pages167–174 “Submersible observations and collections reveal that a probable relict reef off the west coast of Barbados has a rich cover of sponges, along with algae and scattered corals, on a substrate of algal nodules in a muddy-sand matrix. The collections provide new data on the distributions of these fauna. This relict reef is about 20 km long, has a relief of up to 10 m, and is established at a depth of 80 m. Relict shallow-water features in other areas at similar depths along with data from core holes drilled off the south coast of Barbados suggest that this reef was probably established about 12,000 years ago and existed for no more than 2,000 years, during the Holocene sea-level transgression.”
Submerged Reefs of Eastern Caribbean
Ian G. Macintyre AAPG Bulletin Volume: 56 (1972) p 720-728
Abstract:
Submerged early Holocene or late Pleistocene reefs up to 90 km long and with bottom relief commonly about 20 m were established in relation to preexisting lower sea levels on outer edges of terraces at 30-80-m depths off most islands in the eastern Caribbean Sea. Submerged reefs are far more impressive physiographic features than their modern counterparts and are in depths greater (below about 15-20 m) than those commonly associated with present reef-framework construction by hermatypic corals. Data from echo-sounder profiles, rock dredging, bottom photographs, and in situ observations indicate that off the Virgin Islands, St. Martin, St. Barthelemy, Montserrat, Guadeloupe, Martinique, St. Lucia, and the Grenadine Islands submerged reefs are dead and covered by only a few scattered living corals. Hermatypic corals below 15 m on these reefs cannot cope with skeletal destruction by boring organisms and cannot compete for substrate with other encrusting or attached organisms. Off the west coast of Barbados, however, reef-framework construction is still occurring below about 15 m. The age relations of these reefs are not known, but probably they are no older than late Pleistocene and started to grow no later than 8,000 years ago. Although the eastern Caribbean area is characterized by inner-shelf fringe reefs, the common occurrence of shelf-edge submerged reefs indicates that, during the latter stages of the Holocene transgression, reefs were generally adjacent to deep waters, as are modern Pacific barrier and atoll reefs.
Submerged coral reefs, west coast of Barbados, West Indies
IG Macintyre – Canadian Journal of Earth Sciences, Canadian Journal of Earth Sciences, 1967, 4(3): 461-474
Seven sonar profiles of the sea floor were made at 3–mile intervals approximately perpendicular to the west coast of Barbados, W.I. Evidence from these profiles, first-hand observations, and deep-sea camera photographs indicate that two submerged barrier reefs parallel the coast at approximate depths of 70 and 230 ft. A trench is present in a deeper part of the sloping sea floor behind a small ridge at an average depth of 619 ft.The positions of the submerged barrier reefs probably were controlled by pauses in the post-Pleistocene eustatic rise in sea level. The First Ridge was established on an erosional terrace that could have been cut during a stillstand between 12 500 and 11 500 years B.P. The Second Ridge may have been established on a narrow ledge eroded during a stillstand between 16 500 and 15 000 years B.P. The trench appears to have resulted from faulting or submarine outcropping of Tertiary sedimentary rocks.
A revised morpho- and chronostratigraphy of the Late and Middle Pleistocene coral reef terraces on Southern Barbados (West Indies)
G. Schellmann & U. Radtke 2004. in Earth-Science Reviews. “The Barbados coral reef terraces are one of the few type localities worldwide that provide insights into interglacial sea level change during the Late and Middle Pleistocene. Several sea level estimates have been established since the late 1960s and each has contributed to the “Barbados Model” of sea level change…Our study of these geomorphic features, combined with new numeric dating results (ESR, U/Th), enable a revised estimate of the spatial and temporal variation in tectonic uplift rate within south Barbados. These new rates are an essential requirement for more precise glacio-eustatic sea level reconstructions during the Late and Middle Pleistocene from this region.”
The coral reef terraces of Barbados – a guide
Barbados 2002 International Conference on “Quaternary Sea Level Change” with field trips and Fourth Annual Meeting of IGCP Project 437 “Coastal Environmental Change during Sea Level Highstands: A Global Synthesis with Implications for Management of Future Coastal Change” ; INQUA Commission on Coastlines, IGU Commission on Coastal Systems ; 26 October – 2 November 2002, Barbados (W. I.) PDF available
Multi-stage reef development on Barbados during the Last Interglaciation
Paul Blanchon and Anton Eisenhauer. Quaternary Science Reviews 20 (2001) 1093}1112
Full paper available
The geology of Barbados: a field guide
STEPHEN K. DONOVAN (including a joint contribution with DAVID A.T. HARPER
Caribbean Journal of Earth Science, 38 (2005), 21-33.
GEOARCHAEOLOGY OF THE CAVES OF BARBADOS, WEST INDIES
Michael J. Lace et al. 2013 Journal of Caribbean Archaeology
Geology of Barbados: A Brief Account of the Island’s Origin and Its Major
Geological Features
Machel, H.G., 1999, Barbados Museum and Historical Society, The Garrison, St. Michael, Barbados, 52 p.
Pleistocene-Holocene Karstification of Barbados and its implications for the Devonian Grosmont reservoir
Hans MachelHans Machel et al., 2012. GeConvention 2012. “About 80% of the surface of Barbados is made up of Quaternary carbonates with ages approximately 800,000 years to recent. These carbonates are extensively overprinted by epigene (top-down) karst processes. Epigene karst features include various types of caves, solution valleys, and sinkholes. Flank margin caves are the most common cave type. Sinkhole density is high, with an average of 5 sinkholes per square km. However, some areas have a much higher density while others are almost devoid of sinkholes…” Nice overview map showing geological features of Barbados
Machel, H.G., 2009, Caves of Barbados – Wonders and dangers underground. The Barbados Advocate, March-01-2009, 33-40.
Machel, H.G., 2011, The geology of Barbados – a little paradise in its own right. In: Carrington, C.M.S. (ed.): Preserving Paradise. Barbados Museum and Historical Society, 13-51.
Travels in Geology: Barbados: Ascending the sea-level staircase
By Terri Cook and Lon Abbott on /www.earthmagazine.org/ December 7, 2011
Quaternary reef response to sea-level and environmental change in the western Atlantic
Eberhard Gischler in Sedimentology 16 October 2014…”Many reefs in the western Atlantic region kept pace with Holocene sea-level rise whereas some were drowned. Reasons for reef drowning are debated and include sea-level rise, elevation of antecedent topography, and deterioration of environmental conditions such as high nutrient input. Apart from sea-level and antecedent topography, factors such as exposure to waves and currents, storms, and sedimentation have controlled reef development. The historical decline of acroporid corals in the Caribbean realm has been attributed to cooling following the Holocene thermal optimum; however, historical die-offs of reef-building corals and other reef organisms suggest that some if not all recent declines were unprecedented during the Holocene. Rising temperatures, decreasing carbonate saturation, increased frequency of major storms, high nutrient concentrations and sedimentation, overfishing, and disease certainly played a role in decline, but systematic studies relating these environmental factors to Holocene reef-building are only in the early stages.”
Travels in Geology: Barbados: Ascending the sea-level staircase
by Terri Cook and Lon Abbott June 7, 2018 in Earth Magazine. Illustrated with photos
MWP-1C and reef drowning: Morphological evidence along the eastern Brazilian margin
P.H. Cetto et al, 2024 in Marine Geology “Abstract:
Following the Last Glacial Maximum (LGM), the marine transgression experienced intermittent periods of accelerated sea-level rise related to melt water pulses (MWP) in polar regions, preceded by intervals of stillstands. Global stratigraphic and relict geomorphology studies have unveiled the impact of such sea-level rise variability on the formation and submergence of coastal and shallow shelf environments far from the melting source. Despite the opportunity to document these processes with reduced isostatic effects, there are still limited research focused on the South Atlantic continental margins. In this scenario, the present work contributes to investigating the possible..
Introduction “Since the pioneer works of Fairbanks (1989) and Macintyre et al. (1991), based on the stratigraphic record of A. palmata dominated fossil reefs in Barbados, extensive evidence from around the world has demonstrated the temporal variability of sea-level rise rates and their magnitudes during the post-LGM marine transgression. The last ∼21,000 years B.P. were marked by periods or pulses of increased sea-level rise rates known as “Melt Water Pulses” (MWPs), originated from episodes of detachment/release of ice sheets and/or large-scale freshwater discharges into the oceans (Harrison et al., 2019; Cronin, 2012; Carlson and Clark, 2012).
Fairbanks, R.A., 1989. 17,000-year glacio-eustatic sea-level record: influence of glacial melting rates on the Younger Dryas event and deep-ocean circulation. Nature 342, 637–642. https://doi.org/10.1038/342637a0. “Coral reefs drilled offshore of Barbados provide the first continuous and detailed record of sea level change during the last deglaciation. The sea level was 121 ± 5 metres below present level during the last glacial maximum. The deglacial sea level rise was not monotonic; rather, it was marked by two intervals of rapid rise. Varying rates of melt-water discharge to the North Atlantic surface ocean dramatically affected North Atlantic deep-water production and oceanic oxygen isotope chemistry. A global oxygen isotope record for ocean water has been calculated from the Barbados sea level curve, allowing separation of the ice volume component common to all oxygen isotope records measured in deep-sea cores.”
Macintyre, I.G., Rutzler, K., Norris, J.N., et al., 1991. An early Holocene reef in the western Atlantic: submersible investigations a deep relict reef off the west coast of Barbados, W.I. Coral Reefs 10, 167–174. https://doi.org/10.1007/BF00572177. “Submersible observations and collections reveal that a probable relict reef off the west coast of Barbados has a rich cover of sponges, along with algae and scattered corals, on a substrate of algal nodules in a muddy-sand matrix. The collections provide new data on the distributions of these fauna. This relict reef is about 20 km long, has a relief of up to 10 m, and is established at a depth of 80 m. Relict shallow-water features in other areas at similar depths along with data from core holes drilled off the south coast of Barbados suggest that this reef was probably established about 12,000 years ago and existed for no more than 2,000 years, during the Holocene sea-level transgression.”