Primary and diagenetic carbonates in the anoxic sediments of Lake Bosumtwi, Ghana

Journal Article · Sat Nov 01 00:00:00 EST 1986 · Geology; (United States)

DOI:https://doi.org/10.1130/0091-7613(1986)14<912:PADCIT>2.0.CO;2· OSTI ID:5754825

Talbot, M R; Kelts, K

Cores of organic-rich muds from the tropical meteorite crater Lake Bosumtwi, Ghana, contain laminae of authigenic calcite polyhedra and aragonite needles, as well as scattered diagenetic calcite, Mg-calcite spherulites, and aggregates of dolomite crystals. Their respective origins are traced by analyses of oxygen and carbon stable isotopes. Anoxic dolomite and Mg-calcite formed in pore waters reflecting highest degrees of evaporative concentration and high rates of methanogenesis. Carbon dioxide reduction must have been the dominant methanogenic pathway, producing diagenetic carbonates with ..delta../sup 13/C values up to + 27% PDB. This example shows the inherent problems of interpreting bulk samples with progressive mineralogical sequences of calcite to Mg-calcite to aragonite to dolomite merely in terms of Mg/sup 2 +//Ca/sup 2 +/ in lake waters. It provides a model for the interpretation of ancient lacustrine carbonates from organic-rich environments.

• Research Organization: Universitetet i Bergen, Norway
• OSTI ID: 5754825
• Journal Information: Geology; (United States), Vol. 14:11
• Country of Publication: United States
• Language: English

Related Subjects

03 NATURAL GAS
GEOLOGIC DEPOSITS
DIAGENESIS
MINERALOGY
GHANA
NATURAL GAS DEPOSITS
GEOLOGIC MODELS
CALCITE
CARBON DIOXIDE
CARBONATE ROCKS
DOLOMITE
LAKES
METHANE
ORGANIC MATTER
REDUCTION
SEDIMENTS
SYNTHESIS
AFRICA
ALKALINE EARTH METAL COMPOUNDS
ALKANES
CALCIUM CARBONATES
CALCIUM COMPOUNDS
CARBON COMPOUNDS
CARBON OXIDES
CARBONATE MINERALS
CARBONATES
CHALCOGENIDES
CHEMICAL REACTIONS
DEVELOPING COUNTRIES
HYDROCARBONS
MAGNESIUM CARBONATES
MAGNESIUM COMPOUNDS
MINERAL RESOURCES
MINERALS
ORGANIC COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
RESOURCES
ROCKS
SEDIMENTARY ROCKS
SURFACE WATERS
030200* - Natural Gas- Reserves
Geology
&amp; Exploration