Diagenetic dolomite formation in a Holocene evaporitic lake

Conference · Fri Mar 01 00:00:00 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-; CODEN: AABUD
• Journal Information: AAPG Bulletin (American Association of Petroleum Geologists); (United States), Vol. 75:3; Conference: Annual meeting of the American Association of Petroleum Geologists (AAPG), Dallas, TX (United States), 7-10 Apr 1991; ISSN 0149-1423
• Country of Publication: United States
• Language: English

Related Subjects

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