Diagenetic history of a submerged Pleistocene Jamaican fringing reef
- 65 Downloads
In the Discovery Bay area of northern Jamaica, a fringing reef grew and was subsequently planed off as sea level rose to and fell from a highstand between about 132,000 and 147,000 y B.P. Depositional facies encountered in cores consist of back reef, reef flat, reef crest, and shallow fore-reef zones, and many appear to have a storm-modified fabric analogous to the modern fringing reef. Eustatic changes in sea level resulted in 3 periods of marine submergence, and two periods of emergence in a meteoric vadose regime.
Diagenetic fabrics in times of marine submergence include micritization, sedimentation and lithification of extensive mud drapes, and precipitation of high-magnesian calcite, aragonite, and dolomite cements. Mixing zone fabrics include dissolution of aragonite and magnesian calcites. Dissolution of aragonite and subsequent precipitation of whisker calcite (“lublinite”) and other thin-bladed crystals of calcite occurred in the meteoric vadose environment. Thick-bladed to equant low-magnesian calcite filled pores saturated with meteoric water. In contrast to the subaerially exposed 125 Ka Falmouth Formation, no extensive caliche-like “caprock” is associated with the surface of submarine exposure, which is undergoing extensive biological erosion today, or is directly overlain by Holocene deposits.
Marine diagenetic fabrics dominate the rocks today, and a poor and incomplete record of eustatic changes is preserved.
KeywordsDolomite Aragonite Micrite Dolomitization Peloids
Unable to display preview. Download preview PDF.
- Folk, R. L., Chaftez, H. S., and Tiezzi, P. A., 1985, Bizarre forms of depositional and diagenetic calcite in hot-spring travertines, central Italy, in: N. Scheidermann and P. M. Harris, eds., Carbonate Cements, Soc. Economic Paleontologists and Mineralogists Spec. Pub. 36, p. 349–369.Google Scholar
- Friedman, G. M., 1985, The problem of submarine cement in classifying reefrock: An experience in frustration, in: N. Scheidermann and P. M. Harris, eds., Carbonate Cements, Soc. Economic Paleontologists and Mineralogists Spec. Pub. 36, p. 117–121.Google Scholar
- Harmon, R. S., Mitterer, R. M., Kriausakul, N., Land, L. S., Schwarcz, H. P., Garret, P., Larson, G. J., Vacher, H. L., andRowe, M., 1983, U-series and amino-acid racemization geochronology of Bermuda: Implications for eustatic sea-level fluctuation over the past 250,000 years: Palaeogeography, Palaeoclimatology, Palaeoecology, v. 44, p. 41–70.CrossRefGoogle Scholar
- Hubbard, D. K., Miller, A. I., andScaturo, D., 1990, Production and cycling of calcium carbonate in a shelf-edge reef system (St. Croix, U.S. Virgin Islands): Applications to the nature of reef systems in the fossil record: Jour. Sedimentary Petrology, v. 60, p. 335–360.Google Scholar
- Land, L. S., 1989, Dolomitization of the Hope Gate Formation, North Jamaica, by seawater: Reassessment of mixing-zone dolomite: S. Epstein 70th Birthday Symposium, California Inst. Tech., Abstracts with Program, p. 43–45.Google Scholar
- Land, L. S., andMoore, C. H., 1980, Lithification, micritization, and syndepositional diagenesis of biolithites on the Jamaican island slope: Journal of Sedimentary Petrology, v. 50, p. 357–370.Google Scholar
- Lund, H. J., 1989, Marine dolomite in a fore-reef hardground, Discovery Bay, Jamaica [Masters Thesis]: University of Texas, Austin, 98 p.Google Scholar
- Lundberg, 1990, U-series dating of carbonates by mass spectrometry [Ph.D. Thesis]: McMaster University.Google Scholar
- Macintyre, I. G., 1985, Submarine cements—The peloidal question, in: N. Scheidermann and P. M. Harris, eds., Carbonate Cements, Soc. Economic Paleontologists and Mineralogists Spec. Pub. 36, p. 109–116.Google Scholar
- McCullough, M. L., 1990, Diagenetic history and dynamic hydrology of a Jamaican fringing reef [Masters Thesis]: University of Texas, Austin, 144 p.Google Scholar
- McCullough, M. L., and Land, L. S., 1992, Dynamic hydrology of a Jamaican fringing reef: Marine Geology.Google Scholar
- Mitchell, J. T., 1987, Submarine lithification of a Holocene reef hardground: Discovery Bay, Jamaica [Masters Thesis]: University of Texas, Austin, 198 p.Google Scholar
- Stoops, G. J., 1976, On the nature of “lublinite” from Hollanta (Italy): American Mineralogist, v. 61, p. 172.Google Scholar
- Ward, W. C., 1975, Petrology and diagenesis of carbonate eolianites of northeastern Yucatan Peninsula, Mexico: American Association of Petroleum Geologists Studies in Geology, v. 2, p. 500–571.Google Scholar