Carbonate Pb-Pb ages of the Wittenoom Formation and Carawine Dolomite, Hamersley Basin, Western Australia (with implications for their correlation with the Transvaal Dolomite of South Africa)

Title:
Carbonate Pb-Pb ages of the Wittenoom Formation and Carawine Dolomite, Hamersley Basin, Western Australia (with implications for their correlation with the Transvaal Dolomite of South Africa)
Authors:
Jahn, Bor-ming; Simonson, Bruce M.
Abstract:
Pb isotopic analyses of carbonates from the Hamersley Group, Western Australia, yield the following results. (1) A late Archean (minimum) age of 2.5 Ga is definitely established for the deposition of both the deeper-water basinal Wittenoom Formation and the shallow-water Carawine Dolomite. Stratigraphic correlation of the Transvaal Dolomite (South Africa) with these two formations is supported by the present Pb isotope age data. (2) A Pb-Pb isochron age of 2505 ± 37 Ma for the Paraburdoo Member (lower part) of the Wittenoom Formation is best interpreted as a late diagenetic event, which took place ~ 100 Ma after the initial deposition. (3) A Pb-Pb isochron age of 2346 ± 38 Ma for the Bee Gorge Member most likely represents a still later local event of calcite replacement in fractures and veins. (4) A Pb-Pb isochron age of 2541 ± 32 Ma for Carawine Dolomite could represent a regional diagenesis slightly earlier than the Paraburdoo carbonates if the Carawine carbonates were deposited contemporaneously with the Wittenoom Formation. Alternatively, it may represent the time of early diagenesis which closely followed the initial sedimentation. A study of trace element abundances and stable isotope compositions has revealed a major difference in Fe and Mn contents and δ18O values between the Wittenoom and Carawine dolomite samples. This suggests that the two suites of dolomites have undergone separate diagenetic histories with different chemical and oxygen isotopic modifications.
Citation:
Jahn, Bor-ming, and Bruce M. Simonson. 1995. "Carbonate Pb-Pb ages of the Wittenoom Formation and Carawine Dolomite, Hamersley Basin, Western Australia (with implications for their correlation with the Transvaal Dolomite of South Africa)." Precambrian Research 72(3-4): 247-261.
Publisher:
Elsevier
DATE ISSUED:
1995-04
Department:
Geology
Type:
article
Additional Links:
http://rave.ohiolink.edu/ejournals/article/334650677
PERMANENT LINK:
http://hdl.handle.net/11282/309669

Full metadata record

DC FieldValue Language
dc.contributor.authorJahn, Bor-mingen_US
dc.contributor.authorSimonson, Bruce M.en_US
dc.date.accessioned2013-12-23T16:14:40Z-
dc.date.available2013-12-23T16:14:40Z-
dc.date.issued1995-04en
dc.identifier.citationJahn, Bor-ming, and Bruce M. Simonson. 1995. "Carbonate Pb-Pb ages of the Wittenoom Formation and Carawine Dolomite, Hamersley Basin, Western Australia (with implications for their correlation with the Transvaal Dolomite of South Africa)." Precambrian Research 72(3-4): 247-261.en_US
dc.identifier.issn0301-9268en_US
dc.identifier.urihttp://hdl.handle.net/11282/309669-
dc.description.abstractPb isotopic analyses of carbonates from the Hamersley Group, Western Australia, yield the following results. (1) A late Archean (minimum) age of 2.5 Ga is definitely established for the deposition of both the deeper-water basinal Wittenoom Formation and the shallow-water Carawine Dolomite. Stratigraphic correlation of the Transvaal Dolomite (South Africa) with these two formations is supported by the present Pb isotope age data. (2) A Pb-Pb isochron age of 2505 ± 37 Ma for the Paraburdoo Member (lower part) of the Wittenoom Formation is best interpreted as a late diagenetic event, which took place ~ 100 Ma after the initial deposition. (3) A Pb-Pb isochron age of 2346 ± 38 Ma for the Bee Gorge Member most likely represents a still later local event of calcite replacement in fractures and veins. (4) A Pb-Pb isochron age of 2541 ± 32 Ma for Carawine Dolomite could represent a regional diagenesis slightly earlier than the Paraburdoo carbonates if the Carawine carbonates were deposited contemporaneously with the Wittenoom Formation. Alternatively, it may represent the time of early diagenesis which closely followed the initial sedimentation. A study of trace element abundances and stable isotope compositions has revealed a major difference in Fe and Mn contents and δ18O values between the Wittenoom and Carawine dolomite samples. This suggests that the two suites of dolomites have undergone separate diagenetic histories with different chemical and oxygen isotopic modifications.en_US
dc.language.isoen_USen_US
dc.publisherElsevieren_US
dc.relation.urlhttp://rave.ohiolink.edu/ejournals/article/334650677en_GB
dc.subject.departmentGeologyen_US
dc.titleCarbonate Pb-Pb ages of the Wittenoom Formation and Carawine Dolomite, Hamersley Basin, Western Australia (with implications for their correlation with the Transvaal Dolomite of South Africa)en_US
dc.typearticleen_US
dc.identifier.journalPrecambrian Researchen_US
dc.identifier.volume72en_US
dc.identifier.issue3-4en_US
dc.identifier.startpage247en_US
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