Authors / CoAuthors
Jackson, K.S.
Abstract
In the Georgina Basin, the Toko Syncline is considered the most prospective region for petroleum exploration. The syncline contains up to 5000 m of Middle Cambrian to Middle Ordovician sediments and has been the site of six petroleum exploration wells, three of which showed traces of gas, oil, and solid bitumen. Geochemical data for cores from two stratigraphic holes, GSQ Mount Whelan Nos. I and 2, and data from four exploration wells, held on open file at BMR, are used to evaluate the organic maturation and rock potential of the sediments in the Toko Syncline. Source rocks are not recognised in the Ordovician; however, source rocks of generally good quality are present in the Middle and Upper Cambrian. While doubts do exist over the stratigraphic correlations for the wells involved in this study, the Middle Cambrian Marqua beds are considered to be the best source interval. Maturity for oil generation is achieved in the Upper Cambrian to Lower Ordovician Ninmaroo Formation at the Mount Whelan location. However, in the deeper western area, where the better exploration prospects are likely to exist, maturity in Mirrica No. 1 is reached in the Lower to Middle Ordovician Carlo Sandstone. Over-maturity for oil generation, but still in the gas generation phase, is generally observed in the Middle Cambrian. An oil stain in the Lower Ordovician Coolibah Formation in GSQ Mount Whelan No.2 (also described as bitumen plugging porosity) is interpreted as having originated in and having migrated from the Cambrian source rock intervals.
Product Type
document
eCat Id
81095
Contact for the resource
Custodian
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Custodian
Cnr Jerrabomberra Ave and Hindmarsh Dr GPO Box 378
Canberra
ACT
2601
Australia
Keywords
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- GA PublicationJournal
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- QLD
- Australian and New Zealand Standard Research Classification (ANZSRC)
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- Earth Sciences
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- Published_External
Publication Date
1982-01-01T00:00:00
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unknown
Topic Category
geoscientificInformation
Series Information
BMR Journal of Australian Geology and Geophysics 7:1:1-10
Lineage
Unknown
Parent Information
Extents
[-25.0, -22.0, 138.0, 140.0]
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