Holocene–Pleistocene Geology of a Transect of an Isolated Carbonate Platform, NW Caicos Platform, British West Indies

Villa

2022

Earth Syst. Sci. Data

Abstract. This paper provides a summary of published sea-level archives representing the past position of sea level during the Last Interglacial sea-level highstand in the Bahamas, Turks and Caicos, and the eastern (Atlantic) coast of Florida, USA. These data were assembled as part of a community effort to build the World Atlas of Last Interglacial Shorelines (WALIS) database. Shallow marine deposits from this sea-level highstand are widespread across the region and are dominated by carbonate sedimentary features. In addition to depositional (constructional) sedimentary indicators of past sea-level position, there is also evidence of erosion, dissolution, and/or subaerial exposure in places that can place an upper limit on the position of sea level. The sea-level indicators that have been observed within this region and attributed to Marine Isotope Stage (MIS) 5e include corals, oolites, and other coastal sedimentary features. Here we compile a total of 50 relative sea-level indicators including 36 in the Bahamas, three in West Caicos, and a remaining 10 for the eastern seaboard of Florida. We have also compiled U-Th age data for 24 fossil corals and 56 oolite samples. While some of these archives have been dated using U-Th disequilibrium methods, amino acid racemization, or optically stimulated luminescence, other features have more uncertain ages that have been deduced in the context of regional mapping and stratigraphy. Sedimentary archives in this region that constrain the elevation of the past position of sea level are associated with uncertainties that range from a couple of decimeters to several meters. Across the Bahamas and on West Caicos, one of the observations that emerges from this compilation is that estimation of sea-level position in this region during Marine Isotope Stage 5e is complicated by widespread stratigraphic evidence for at least one sea-level oscillation. This evidence is defined by submarine features separated by erosion and subaerial exposure, meaning that there were likely multiple distinct peaks in sea level rather than just one. To this end, the timing of these individual sea-level indicators becomes important when compiling and comparing data across the region given that different archives may have formed during different sub-orbital peaks in sea level. The database can be found at https://doi.org/10.5281/zenodo.5596898 (Dutton et al., 2021).

Section: Turks and Caicos Sea-level Indicatorsmentioning

confidence: 99%

Compilation of Last Interglacial (Marine Isotope Stage 5e) sea-level indicators in the Bahamas, Turks and Caicos, and the east coast of Florida, USA

Villa

2022

Earth Syst. Sci. Data

“…U-series ages have been reported for 19 corals collected from the LIG Boat Cove and South Reef units on West Caicos (Kindler and Meyer, 2012;Kerans et al, 2019). Additional mass spectrometric U-series ages have been reported by Simo et al (2008), but the type of material dated ranged from "well preserved coral, to skeletal grains and ooids". As Simo et al (2008) did not specify which carbonate material was dated for each of their ages, their dataset was not included in the present compilation.…”

Section: Turks and Caicosmentioning

confidence: 99%

A global compilation of U-series-dated fossil coral sea-level indicators for the Last Interglacial period (Marine Isotope Stage 5e)

2021

Earth Syst. Sci. Data

Abstract. This dataset is a comprehensive, global compilation of published uranium–thorium (U-series) dated fossil coral records from ∼ 150 000–110 000 years ago, as well as associated elevation measurements and sample metadata. In total, 1312 U-series measurements from 994 unique coral colonies are included in the current version of the dataset, all of which have been normalized and recalculated using the same decay constant values. Of these measurements, 444 analyses from 330 colonies are relative sea-level indicators, whereas 15 analyses from 13 colonies are marine limiting. Two example geochemical screening criteria have been included to assist users with identifying altered fossil corals that display geochemical open-system behavior, and the originally published interpretations on age quality have been preserved within the sample metadata. Additionally, a clear distinction has been made between coral colonies that are in primary growth position, which may be used for relative sea-level reconstructions, and colonies that have been transported/reworked, which cannot be used for these purposes. Future research efforts involving fossil coral sea-level reconstructions should emphasize an “integrated” and holistic approach that combines careful assessment of U-series age quality with high-precision surveying techniques and detailed facies/stratigraphic observations. This database is available at https://doi.org/10.5281/zenodo.4309796 (Chutcharavan and Dutton, 2020).

“…U-series ages have been reported for 19 corals collected from the LIG Boat Cove and South Reef units on West Caicos (Kindler and Meyer 2012;Kerans et al 2019). Additional mass spectrometric U-series ages have been reported by Simo et al (2008), but the type of material dated ranged from "well preserved coral, to skeletal grains and ooids". As Simo et al (2008) did not specify which carbonate material was dated for each of their ages, their dataset was not included in the present compilation.…”

Section: Turks and Caicosmentioning

confidence: 99%

A Global Compilation of U-series Dated Fossil Coral Sea-level Indicators for the Last Interglacial Period (MIS 5e)

2020

Preprint

Abstract. This dataset is a comprehensive, global compilation of published uranium series (U-series) dated fossil coral records from ~150–110 thousand years ago, as well as associated elevation measurements and sample metadata. In total, 1312 U-series measurements from 994 unique coral colonies are included in the current version of the dataset, all of which have been normalized and recalculated using the same decay constant values. Two example geochemical screening criteria have been included to assist users with identifying altered fossil corals that display geochemical open-system behaviour, and the originally published interpretations on age quality have been preserved within the sample metadata. Additionally, a clear distinction has been made between coral colonies that are in primary growth position, which may be used for relative sea-level reconstructions and colonies that have been transported/reworked, which cannot be used for these purposes. Future research efforts involving fossil coral sea-level reconstructions should emphasize an integrated and holistic approach that combines careful assessment of U-series age quality with high-precision surveying techniques and detailed facies/stratigraphic observations. This database is available at http://doi.org/10.5281/zenodo.4309796 (Chutcharavan and Dutton 2020).