This article was accepted into the corpus but its outbound wikilinks were never NER-processed — typical at the deepest BFS hop or when the run's entity cap was reached. No expansion funnel to show.
| Patchawarra Formation | |
|---|---|
| Name | Patchawarra Formation |
| Period | Permian |
| Age | Guadalupian to Lopingian |
| Region | Cooper Basin, Central Australia |
| Country | Australia |
| Lithology | Sandstone, siltstone, shale, coal |
| Namedfor | Patchawarra |
Patchawarra Formation The Patchawarra Formation is a Permian stratigraphic unit in the Cooper Basin of central Australia associated with petroleum-bearing strata and coal-bearing intervals. It has been the subject of regional studies by Australian stratigraphers, sedimentologists, and petroleum geologists working with institutions such as the Australian Petroleum Production and Exploration Association, the Bureau of Mineral Resources, and state geological surveys. Major exploration and production activities by companies including Santos, Origin Energy, and Chevron have targeted its reservoirs within structural and stratigraphic traps.
The Formation crops out and subcrops across the Cooper Basin near notable localities such as Eromanga, Manners Creek, and the Durham Downs region and lies within administrative regions governed by the Queensland and South Australia boundaries. Scholarly syntheses reference the Formation in regional syntheses alongside units like the Arapahoe Formation, Bulloo Formation, and Toolachee Formation and in basin-wide studies by the Australian Bureau of Mineral Resources and the Geological Society of Australia. Exploration history ties to petroleum booms driven by discoveries in basins such as the Cooper Basin, Eromanga Basin, and corridors linked to infrastructure like the Moomba Gas Plant.
The lithological assemblage comprises interbedded lithic and feldspathic sandstone, siltstone, shale, carbonaceous mudstone, and local coal seams, with common mineral constituents cited in thin section studies by university groups at University of Adelaide, University of Queensland, and Monash University. Petrographic descriptions reference quartzose sandstones with clay matrices, glauconitic horizons, and authigenic cements similar to those reported from Permian successions correlated by researchers at the CSIRO. Detrital framework grains and heavy mineral suites have been compared with provenance signatures examined by the Australian National University and the Geoscience Australia laboratory programs.
The formation is assigned to Guadalupian–Lopingian (Middle–Late Permian) intervals established through biostratigraphic correlation, palynology, and regional chronostratigraphic frameworks developed by teams associated with the International Commission on Stratigraphy and national stratigraphic committees. It forms part of a stratigraphic succession that overlies older units correlated to the Baralaba Coal Measures and is overlain by younger Triassic and Jurassic cover sequences recognized in basin cross sections prepared by consultants to Santos and government mapping programs. Correlation markers include characteristic palynomorph assemblages and regional unconformities utilized in industry well log correlation workflows.
Interpretations envisage fluvial to deltaic and marginal marine depositional settings with distributary channel sandstones, overbank siltstones, and interdistributary swamp facies generating carbonaceous shales and thin coal seams; these interpretations are supported by sedimentary architecture studies conducted by research groups at the University of Sydney and consulting firms serving Origin Energy. Facies models align with analogues from Permian sequences studied in basins such as the Sydney Basin and Eromanga Basin, and sediment transport and paleocurrent data have been compared to source terrains referenced in regional tectonic reconstructions including work by geoscientists at the University of Melbourne.
The Formation is an important reservoir and source interval within the Cooper Basin petroleum system, hosting conventional gas and condensate accumulations exploited via fields tied to processing facilities such as the Moomba Gas Plant and pipelines operated by companies like Santos and Epic Energy. Reservoir quality is controlled by sandstone body geometry, diagenetic alteration, and fault-related compartmentalization mapped in seismic campaigns executed by multinational service firms including Schlumberger and Halliburton. Hydrocarbon charge, maturation, and expulsion models reference heat flow histories and vitrinite reflectance data compiled in basin studies by the APPEA Research Centre and government geoscience agencies.
Fossil content is largely palynological, with plant spores and pollen assemblages used for biostratigraphy and paleoenvironmental reconstruction by palynologists at institutions such as the Western Australian Museum and the Queensland Museum. Reports include records of glossopterid, pteridosperm, and lycopsid palynomorphs that align with Gondwanan Permian floras documented in comparative studies involving collections from the South African Museum and the Natural History Museum, London. Occasional invertebrate and ichnofossil traces in marginal marine facies provide additional environmental indicators used in regional paleoecological syntheses.
Economic interest centers on hydrocarbon production and potential coal and unconventional resources assessed by major energy companies like Santos, Chevron, and Origin Energy as well as service contractors and exploration consortia supported by government promotion via agencies such as Geoscience Australia. Basinal evaluation, reserve estimation, and development planning have been integral to state revenue strategies in Queensland and South Australia and underpin continuing appraisal drilling, seismic acquisition, and appraisal of enhanced recovery techniques promoted by international firms including Shell and ConocoPhillips.
Mapping and research involve contributions from the Bureau of Mineral Resources (Australia), later integrated into the Geoscience Australia framework, with academic studies by researchers at The University of New South Wales and industry technical reports archived with state geological surveys. Historic exploration milestones include Early Permian mapping campaigns, 20th-century seismic surveys, and modern integrated reservoir characterization projects employing technologies from companies such as Schlumberger and collaborations with universities and professional bodies like the Geological Society of Australia.
Category:Geologic formations of Australia Category:Permian geology Category:Cooper Basin