TY - JOUR T1 - Coral growth rates from the Holocene Canada Honda fossil reef, Southwestern Dominican Republic: Comparisons with modern counterparts in high sedimentation settings JF - Caribbean Journal of Science Y1 - 2009 A1 - Cuevas, D. N. A1 - Sherman, C. E. A1 - Ramírez, W. A1 - Hubbard, D. K. KW - australia KW - Belize KW - Caribbean KW - community KW - degradation KW - enriquillo valley KW - florida KW - great-barrier-reef KW - linear extension KW - montastraea-annularis KW - paluma shoals KW - record KW - siltation stress KW - skeletal extension KW - turbidity AB - The Holocene Canada Honda fossil reef, located in southwestern Dominican Republic, provides a unique opportunity to examine a well-preserved fossil coral reef that thrived in a high-sedimentation environment between 9,000 to 5,000 years ago. Measurements of coral growth rates from the corals Montastraea faveolata and Siderastrea siderea were conducted and comparisons made with growth rate data of these same species from modern coral reefs throughout the Caribbean. Also, assessments of coral species abundance, morphology, age, and distribution, as well as reef sediment composition, were made to determine the paleoenvironment of reef accretion. This reef is characterized by a high relative abundance of sediment-tolerant coral species that have a tendency to form almost monospecific stands. Individual colonies have a propensity to grow as encrusting, dome-shaped, platy-like forms and specimens of Montastraea faveolata commonly contain bands of sediment incorporated into the skeleton. Calibrated radiocarbon ages of fossil corals range from 9,256 +/- 137 to 6,737 +/- 94.5 BP. Correlation of radiocarbon ages with well-established Holocene sea-level curves indicates that most corals on this reef developed at depths >15m. Measured growth rates in Siderastrea siderea (0.2-0.4 cm/yr) and Montastraea faveolata (0.09-0.44 cm/yr) are relatively low compared with growth rates from modern reef sites, indicating reduced light intensity caused by coral growth at depths greater than 15 m. Reef sediment is characterized by more than 85% carbonate material. A significant portion of the carbonate is allochtonous and was derived from nearby Neogene limestones. The reef was able to survive under high-sedimentation conditions because the high carbonate content of incoming terrigenous sediment would have allowed better light penetration and probable sporadic storms would provide intervening low-sedimentation periods during which reef corals could respond and grow back, keeping-up with sedimentation. VL - 45 SN - 0008-6452 IS - 1 N1 - 695voTimes Cited:0 Cited References Count:47 JO - Caribb J Sci ER - TY - JOUR T1 - An isotopic biogeochemical study of Neoproterozoic and Early Cambrian sediments from the Centralian Superbasin, Australia JF - Geochim Cosmochim Acta Y1 - 1997 A1 - Logan, G. A. A1 - Summons, R. E. A1 - Hayes, J. M. KW - Alkanes/analysis/chemistry KW - Animals KW - australia KW - biomarkers KW - carbon isotopes KW - Carbon/analysis/*chemistry KW - Cyanobacteria KW - Eukaryota KW - Feces KW - Fossils KW - Geologic Sediments/*analysis/chemistry KW - Hydrocarbons/analysis KW - NASA Discipline Exobiology KW - Non-NASA Center KW - Paleontology KW - phytoplankton KW - SEAWATER KW - Terpenes/analysis KW - Zooplankton AB - Organic matter from Neoproterozoic and Early Cambrian sediments of the Amadeus and Officer basins of the Centralian Superbasin, Australia, has been studied for biomarker distributions and the carbon isotopic compositions of kerogen and individual hydrocarbons. These sediments represent both shallow and deep water marine facies in the older sections and marine and saline lacustrine carbonate deposits in the Cambrian. Hydrocarbon biomarker patterns were found to be quite consistent with the known sedimentary environments and provide valuable insights into the biogeochemical changes which accompanied the transition from a microbially-dominated ocean to the early stages of metazoan radiation. In particular, carbon isotopic data for n-alkyl and isoprenoid lipids presented here, and in earlier studies, showed a reversal in carbon isotopic ordering between the Proterozoic and Phanerozoic. By comparison with the delta 13C of kerogen, n-alkyl lipids from deep-water Proterozoic sediments were enriched in 13C and appear to be derived mainly from heterotrophs whilst open marine Phanerozoic counterparts are 13C depleted and evidently derived mainly from autotrophs. Data from the samples studied here are consistent with a model invoking a change in the redox structure of the ocean, possibly aided by the innovation of faecal pellets. VL - 61 SN - 0016-7037 (Print)0016-7037 (Linking) UR - https://www.ncbi.nlm.nih.gov/pubmed/11540731 IS - 24 N1 - Logan, G ASummons, R E Hayes, J M eng Research Support, U.S. Gov't, Non-P.H.S. 1997/01/01 00:00 Geochim Cosmochim Acta. 1997;61(24):5391-409. ER -