Are coral clasts from a turbid near-shore reef environment a suitable material for radiocarbon analysis?

Gulliver, Pauline, Palmer, Suzanne, Perry, Chris, and Smithers, Scott (2013) Are coral clasts from a turbid near-shore reef environment a suitable material for radiocarbon analysis? Radiocarbon, 55 (2-3). pp. 624-630.

[img]
Preview
PDF (Published Version) - Published Version
Available under License Creative Commons Attribution.

Download (198kB)
View at Publisher Website: http://dx.doi.org/10.2458/azu_js_rc.55.1...
 
2
52


Abstract

Use of coral skeletons to determine growth histories of reefs situated in warm, clear tropical waters is well established. Recently, however, there has been increasing awareness of the significance of reefs occurring in environments that are considered as marginal for coral growth, such as turbid inshore settings characterized by episodes of elevated turbidity, low light penetration, and periodic sediment burial. While these conditions are generally considered as limiting for coral growth, coral reefs in these settings can exhibit high live coral cover and species diversity, and thus can be both ecologically and geologically significant. Turbid-zone reefs are also commonly concentrated along eroding shorelines with many analogues to erosional shorelines developed during the Holocene transgression. A growing number of studies of these previously undocumented reefs reveal that the reef deposits are detrital in nature, comprising a framework dominated by reef rubble and coral clasts and set within a fine-grained terrigenous sediment matrix. In addition to the recognized effects of diagenesis or algal encrustations on the radiocarbon signature of coral samples, episodic high-energy events may rework sediments and can result in age reversals in the same stratigraphic unit. As in other reef settings, the possibility of such reworking can complicate the reconstruction of turbid-zone reef growth chronologies. In order to test the accuracy of dating coral clasts for developing growth histories of these reef deposits, 5 replicate samples from 5 separate coral clasts were taken from 2 sedimentary units in a core collected from Paluma Shoals, an inshore turbid-zone reef located in Halifax Bay, central Great Barrier Reef, Australia. Results show that where care is taken to screen the clasts for skeletal preservation, primary mineralogical structures, and δ¹³C values indicative of marine carbonate, then reliable δ¹⁴C dates can be recovered from individual turbid reef coral samples. In addition, the results show that these individual clasts were deposited coevally.

Item ID: 28983
Item Type: Article (Refereed Research - C1)
Additional Information:

This work is licensed under a Creative Commons Attribution 3.0 License.

ISSN: 0033-8222
Funders: Royal Society, Natural Environment Research Council
Date Deposited: 26 Aug 2013 00:32
FoR Codes: 04 EARTH SCIENCES > 0403 Geology > 040303 Geochronology @ 35%
04 EARTH SCIENCES > 0403 Geology > 040305 Marine Geoscience @ 30%
04 EARTH SCIENCES > 0406 Physical Geography and Environmental Geoscience > 040699 Physical Geography and Environmental Geoscience not elsewhere classified @ 35%
SEO Codes: 96 ENVIRONMENT > 9605 Ecosystem Assessment and Management > 960507 Ecosystem Assessment and Management of Marine Environments @ 100%
Downloads: Total: 52
More Statistics

Actions (Repository Staff Only)

Item Control Page Item Control Page