Diagenetic dolomite formation in a Holocene evaporitic lake

Conference · Fri Mar 01 04:00:00 EST 1991 · AAPG Bulletin (American Association of Petroleum Geologists); (United States)

OSTI ID:5529795

Coshell, L; Scott, J ^[1]; Rosen, M; Turner, J V ^[2]

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1. National Key Centre for Resource Exploration, Perth (Australia)
2. Commonwealth Scientific and Industrial Research Organization, Floreat Park (Australia)

Holocene dolomite forms in the sediment of Lake Hayward, a small, permanent, hypersaline lake in the Clifton-Preston Lakeland System, Western Australia. The Clifton-Preston Lakeland System is similar in climate, geography, and sedimentology to the Coorong Region of South Australia. However, dolomite in Lake Hayward is not a primary precipitate as in the Coorong but is of diagenetic origin. The diagenetic origin can be deduced from the combination of the following criteria: (1) the dolomite occurs only between 60-70 cm from the sediment water interface; (2) dolomite occurs as luminescing cement; and (3) dolomite has pristine well-formed rhomb-shaped crystals. The source of magnesium for dolomitization is probably from the concentration of inflowing groundwater by evaporation and the selective removal of calcium by aragonite/calcite precipitation. Although the mechanisms of dolomite formation in Lake Hayward are slightly different than in the Coorong, the presence of Holocene dolomite in an almost identical setting illustrates the importance of the 'Coorong model' for dolomite formation in modern coastal areas.

• OSTI ID: 5529795
• Report Number(s): CONF-910403--
• Conference Information: Journal Name: AAPG Bulletin (American Association of Petroleum Geologists); (United States) Journal Volume: 75:3
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
580000* -- Geosciences
ARAGONITE
AUSTRALASIA
AUSTRALIA
CALCITE
CARBONATE MINERALS
CARBONATE ROCKS
CENOZOIC ERA
CRYSTALLIZATION
CRYSTALLOGRAPHY
DEVELOPED COUNTRIES
DIAGENESIS
DOLOMITE
GEOLOGIC AGES
GEOLOGIC MODELS
INTERFACES
MINERALIZATION
MINERALS
ORIGIN
PHASE TRANSFORMATIONS
PRECIPITATION
QUATERNARY PERIOD
ROCKS
SEDIMENT-WATER INTERFACES
SEDIMENTARY ROCKS
SEDIMENTS
SEPARATION PROCESSES
WESTERN AUSTRALIA