Reef facies distribution patterns, Pleistocene (125 Ka) Falmouth Formation, Rio Bueno, Jamaica, W. I
1991; American Association of Petroleum Geologists; Linguagem: Inglês
ISSN
1558-9153
AutoresWilliam F. Precht, William H. Hoyt,
Tópico(s)Coral and Marine Ecosystems Studies
ResumoDetailed paleoecologic and sedimentologic studies of the well-exposed, Pleistocene (125 Ka) Falmouth Formation from Rio Bueno, Jamaica, where undertaken to define both temporal and spatial changes in reef architecture. Analyses of samples reveal an overall shallowing - upwards motif and a distinct lateral zonation of reefal facies similar to those observed in Recent fringing-reef and bank-barrier reef complexes from the eastern and western sides of Discovery Bay, Jamaica, respectively. The Falmouth Formation that crops out on the eastern shore of Rio Bueno Harbor is continually exposed (north-south) for approximately 0.5 km in length. The top of the reef exposure is approximately +4.5 m above MSL. This height correlates directly with sea level maxima for the Sangamon in Jamaica based upon a wavecut notch in the Hopegate Formation at the top of the Falmouth onlap surface. Interpretation of these deposits indicates that no lagoon or back-reef facies were present and that there was a gradation of energy regimes from high-to-low, north-to-south within this true fringing reef complex. Detailed sedimentologic analysis of thin-sections from all the above lithologies confirms the aforementioned paleoenvironmental interpretations. This study emphasizes the usefulness of modern counterparts in Pleistocene reef analysis and interpretation, and allows for an understandingmore » of temporal (vertical) and spatial (horizontal) variations due to both physical disturbance and local sea level history that are preserved in these reefal deposits.« less
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