Rapid growth rates of syndepositional marine aragonite cements in steep marginal slope deposits, Bahamas and Belize

Journal Article · Wed Sep 01 04:00:00 EDT 1993 · Journal of Sedimentary Petrology; (United States)

OSTI ID:5950146

Grammer, G M; Ginsburg, R N; Swart, P K; McNeill, D F ^[1]; Jull, A J.T. ^[2]; Prezbindowski, D R ^[3]

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1. Univ. of Miami, FL (United States). Div. of Marine Geology
2. Univ. of Arizona, Tucson, AZ (United States). NSF Accelerator Facility
3. International Petrology Research, Noblesville, IN (United States)

Growth rates of marine botryoidal aragonite cements from steep (35-45[degree]) marginal slope deposits in the Bahamas and Belize have been determined by accelerator mass spectrometer radiocarbon dating of samples taken at the base and top of individual botryoids. The pore-filling cements, which range from approximately 11,000-13,000 years old, grew at average rates of 8-10mm/100 yr with maximum rates > 25mm/100 yr. Radiocarbon dating of coexisting skeletal components indicates that cementation was syndepositional. Microsampling transects across individual botryoids for stable-isotope analyses show little variation in [delta][sup 31]C and [delta][sup 18]O, supporting the conclusion that cementation was extremely rapid. Although the cements show a progressive depletion in isotopic composition of approximately 1[per thousand]([delta][sup 13]C) and 2[per thousand]([delta][sup 18]O) from 13 ka to 11 ka, the average variation ([delta][sub 1]) within individual pore-filling cements, ranging in size 2 mm to 32 mm (bottom to top), was 0.11[per thousand]([delta][sup 13]C) and 0.14[per thousand]([delta][sup 18]O). Results of this study provide the first quantitative data on growth rates of marine carbonate cements in a marginal slope environment. The data indicate that marginal slope deposits may lithify within several tens of years and suggest that geologically instantaneous cementation may be critical in stabilizing steep carbonate slope deposits at or above angles of repose.

• OSTI ID: 5950146
• Journal Information: Journal of Sedimentary Petrology; (United States), Journal Name: Journal of Sedimentary Petrology; (United States) Vol. 63:5; ISSN 0022-4472; ISSN JSEPAK
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
580000* -- Geosciences
AGE ESTIMATION
ARAGONITE
BAHAMA ISLANDS
BELIZE
CARBON 13
CARBON ISOTOPES
CARBONATE MINERALS
CARBONATE ROCKS
CENTRAL AMERICA
CONTINENTAL MARGIN
CONTINENTAL SLOPE
DEPOSITION
DEVELOPING COUNTRIES
EVEN-EVEN NUCLEI
EVEN-ODD NUCLEI
GEOLOGIC DEPOSITS
GEOLOGIC HISTORY
GEOLOGY
ISLANDS
ISOTOPE DATING
ISOTOPES
LATIN AMERICA
LIGHT NUCLEI
LIMESTONE
MASS SPECTROSCOPY
MINERALS
NUCLEI
OXYGEN 18
OXYGEN ISOTOPES
PETROLOGY
PRECIPITATION
ROCKS
SEDIMENTARY ROCKS
SEDIMENTS
SEPARATION PROCESSES
SPECTROSCOPY
STABLE ISOTOPES
WEST INDIES