Rapid burial diagenesis of deep-water carbonates; Exuma Sound, Bahamas

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doi: 10.1130/0091-7613(1988)016<0680:RBDODW>2.3.CO;2
Author(s): Dix, George R.; Mullins, Henry T.
Author Affiliation(s): Primary:
Syracuse Univ., Heroy Geol. Lab., Syracuse, NY, United States
Volume Title: Geology (Boulder)
Source: Geology (Boulder), 16(8), p.680-683. Publisher: Geological Society of America (GSA), Boulder, CO, United States. ISSN: 0091-7613 CODEN: GLGYBA
Note: In English. 20 refs.; illus. incl. chart, sketch map
Summary: Well-lithified, deep-water, periplatform limestones of late Miocene age occur at subsurface depths from 113 m to total depth of 283 m at Ocean Drilling Program (ODP) Site 632 in Exuma Sound, Bahamas. This occurrence, marked by a dramatic increase in compressional wave velocities up to 5.0 km/s, represents the most rapid transformation of ooze to limestone yet discovered in either periplatform or open-ocean settings. The burial diagenetic pathway is similar to those for meteoric and deep-burial diagenetic environments: aragonite dissolves, magnesian calcites exsolve or dissolve, low-Mg calcite precipitates as cement, and secondary moldic/vuggy porosity develops. Stable isotope ratios suggest precipitation of low-Mg calcite from cold, marine-derived pore waters. Accelerated diagenesis is a response to the influx of large quantities (up to 80%) of bank-derived, metastable carbonates and rapid burial via high accumulation rates (up to 210 m/m.y.). Our findings (1) document carbonate mineral stabilization and lithification in a seawater-mediated, shallow-burial diagenetic environment; (2) highlight the very high diagenetic potential of periplatform carbonates; and (3) call into question the use of seismic velocities as support for the Bahama megabank hypothesis.
Year of Publication: 1988
Research Program: DSDP Deep Sea Drilling Project
ODP Ocean Drilling Program
Key Words: 02 Geochemistry; 07 Marine Geology and Oceanography; Atlantic Ocean; Bahamas; Burial diagenesis; Carbonate rocks; Caribbean region; Cementation; Cenozoic; Clastic sediments; Cores; DSDP Site 632; Deep Sea Drilling Project; Deep-sea environment; Diagenesis; Exuma Sound; Geochemistry; Leg 101; Limestone; Lithification; Marine environment; Miocene; Neogene; North American Atlantic; North Atlantic; ODP Site 632; Ocean Drilling Program; Oceanography; Ooze; Processes; Rates; SEM data; Sedimentary rocks; Sedimentation; Sediments; Tertiary; Upper Miocene; West Indies
Coordinates: N235000 N235000 W0752600 W0752600
Record ID: 1988053000
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