Territory Stories

The Vaughton Siltstone of the northern McArthur Basin: preliminary data and issues related to assessing its potential as a petroleum source rock

Details:

Title

The Vaughton Siltstone of the northern McArthur Basin: preliminary data and issues related to assessing its potential as a petroleum source rock,

Creator

Frichot, L, Revie, D, Munson, TJ, Frichot, L, Revie, D, Munson, TJ,

Issued by

Northern Territory Geological Survey, Northern Territory Geological Survey,

Collection

E-Publications, E-Books, PublicationNT, NTGS Technical Note, Australia 1:250 000 Geological Map Series Blue Mud Bay SD5307,

Date

2017, 2017,

Location

Blue Mud Bay SD5307, McArthur Basin, Australia 1:250 000 Geological MapBlue Mud Bay SD5307,

Abstract

The Vaughton Siltstone BLUE MUD BAY is a recessive carbonaceous shale unit of the Balma Group (McArthur Basin). Its mineralogy bears similarity to unconventional self-sourcing petroleum shales seen elsewhere in the McArthur Basin. A number of samples from weathered exposures of this formation were analysed in order to assess their hydrocarbon potential. Analyses consisted of X-ray diffraction, shale rock properties, total organic carbon content, programmed pyrolysis, CHONS elemental kerogen content, organic petrography, and gas chromatography. Initial results indicate that petroleum generation has occurred, but very little petroleum has been retained such that the remaining hydrocarbon generative potential is considered negligible. The presence of bitumen within the samples indicates that thermal maturation has occurred, possibly from burial of the siltstone or from exposure to hydrothermal fluids. However, the use of weathered samples, exposed to atmospheric levels of oxygen and large volumes of meteoric water, creates uncertainty within the results; therefore sub-surface samples of fresh material would be required to determine the true petroleum potential., The Vaughton Siltstone BLUE MUD BAY is a recessive carbonaceous shale unit of the Balma Group (McArthur Basin). Its mineralogy bears similarity to unconventional self-sourcing petroleum shales seen elsewhere in the McArthur Basin. A number of samples from weathered exposures of this formation were analysed in order to assess their hydrocarbon potential. Analyses consisted of X-ray diffraction, shale rock properties, total organic carbon content, programmed pyrolysis, CHONS elemental kerogen content, organic petrography, and gas chromatography. Initial results indicate that petroleum generation has occurred, but very little petroleum has been retained such that the remaining hydrocarbon generative potential is considered negligible. The presence of bitumen within the samples indicates that thermal maturation has occurred, possibly from burial of the siltstone or from exposure to hydrothermal fluids. However, the use of weathered samples, exposed to atmospheric levels of oxygen and large volumes of meteoric water, creates uncertainty within the results; therefore sub-surface samples of fresh material would be required to determine the true petroleum potential.,

Notes

Made available via the Publications (Legal Deposit) Act 2004 (NT), Available from GEMIS - Geoscience Exploration and Mining Information System, Made available via the Publications (Legal Deposit) Act 2004 (NT),

Language

English,

Subject

Shale analysis, Shale rock properties, Pyrolysis, Kerogen, X ray diffraction, Total organic carbon (LECO), Rock properties, Geochemistry, Petroleum, McArthur Basin,

Publisher name

Northern Territory Government, Northern Territory Government,

Place of publication

Darwin,

Series

NTGS Technical Note, Australia 1:250 000 Geological Map Series Blue Mud Bay SD5307,

Volume

2017-002,

File type

application/pdf,

Use

Attribution International 4.0 (CC BY 4.0),

Copyright owner

Northern Territory Government, Northern Territory Government,

License

https://creativecommons.org/licenses/by/4.0/, https://creativecommons.org/licenses/by/4.0/,

Related links

https://geoscience.nt.gov.au/gemis/ntgsjspui/handle/1/85278 [GEMIS], https://geoscience.nt.gov.au/gemis/ntgsjspui/handle/1/85278,

Parent handle

https://hdl.handle.net/10070/794447, https://geoscience.nt.gov.au/gemis/ntgsjspui/handle/1/85278,

Citation address

https://hdl.handle.net/10070/794447

Related items

https://hdl.handle.net/10070/794460,