Canning Basin Research Articles

Depositional and lithological control on fractures in a steep, reefal carbonate margin: Lennard Shelf outcrops of the Canning Basin, Western Australia

Depositional and lithological control on fractures in a steep, reefal carbonate margin: Lennard Shelf outcrops of the Canning Basin, Western Australia

Anomalously fertile subcontinental lithospheric mantle beneath the intracontinental Canning Basin, Western Australia

SUMMARY Many intracontinental basins form as broad depressions through prolonged, slow subsidence of the continental lithosphere. Such long-lived basins can record lithospheric processes over hundreds of millions of years, serving as important archives of lithospheric evolution. Since continental amalgamation in the Mesoproterozoic, the lithosphere beneath the intracontinental Canning Basin has been subject to several tectonic events, with extensive crustal reworking evidenced through different upper crust data sets. However, knowledge of the structure of the subcontinental lithospheric mantle is lacking. As a consequence, understanding the coupled evolution between surface and deep lithospheric processes, crucial to resolving basin formation, development and survival, remains problematic. Here, we combine geochemical, geophysical and petrophysical data within a thermodynamic modelling framework to determine the thermochemical properties, rheology, density and seismic structure of the lithospheric and sublithospheric mantle beneath the Canning Basin. The results indicate a thick, rigid lithosphere with a maximum thickness of 185 km and strength of ca. 1 × 1013 Pa m, and an anomalously Fe-enriched subcontinental lithospheric mantle with a Mg# of 88.6. This mantle structure is not consistent with pre-collisional fragments or a Precambrian collisional setting and may reflect magmatic refertilization during high-volume mafic magmatic events. Potential candidate events are the ∼1070 Ma Warakurna, ∼825 Ma Gairdner and ∼510 Ma Kalkarindji Large Igneous Provinces. The youngest of these is temporally and spatially correlated with and therefore interpreted to have influenced the Canning Basin formation. We propose that refertilization caused a negatively buoyant subcontinental lithospheric mantle and prolonged subsidence and preservation of the basin, while the strong lithosphere ensured lithospheric stability and longevity.

The Rafael gas-condensate discovery – a potential game-changer in the Canning Basin

The Rafael 1 exploration well discovered an abnormally high-pressured gas-condensate pool in the Kimberley region in late 2021. Data supports a minimum gross gas column of 165 m at the well location trapped within a large faulted four-way closure in a dolomite reservoir sequence with strong similarities and age equivalent to the oil-bearing Ungani Dolomite reservoir in the Ungani Field. A successful production test in March 2022 resulted in sustained natural flows of gas and condensate to surface. The presence of thick sandstones of the Anderson Formation and a complete Laurel section beneath the Meda Unconformity were unexpected based on the pre-drill interpretation. Serendipitously, it provided the perfect geological setting for a significant hydrocarbon accumulation and emphasised the need to consider multiple geological scenarios when evaluating prospects to capture the full range of uncertainties and potential pool sizes. Although the range in size of the contingent resources is wide and requires further drilling for refinement, the Rafael 1 discovery could be one of the most significant onshore gas discoveries since Waitsia 1 and provides impetus and incentive for continued exploration in the basin. Several pathways for commercialisation have been identified linked to the resource size. A comprehensive appraisal program is underway including the recently completed acquisition of a 200 km2 3D seismic survey to optimally locate wells, and plans for drilling to reduce uncertainty and support the first phase of development based on a low case contingent resource that could underpin the energy needs of the Kimberley region.

Exploring for the Future: new geomechanical data in frontier Australian basins

Led by Geoscience Australia, Exploring for the Future (EFTF) is a A$225 million Australian Government program dedicated to exploring Australia’s resource potential and boosting investment. The EFTF program energy component aimed to attract industry investment by delivering a suite of new precompetitive geoscience data in prospective Australian sedimentary basins. Through EFTF, Geoscience Australia has acquired significant amounts of new geomechanical data from underexplored onshore sedimentary basins with identified hydrocarbon prospectivity, from both legacy and newly acquired samples. These data were acquired to build a better understanding of basin sediment rock properties, particularly looking at the reservoir and seal potential of postulated unconventional and conventional targets. Four major datasets are presented herein, representing prospective intervals from the Paleozoic Canning Basin of Western Australia, the Neoproterozoic-Paleozoic Officer Basin of South Australia and Western Australia, the Paleo-Mesoproterozoic South Nicholson region of the Northern Territory and northwest Queensland, and the Paleo-Mesoproterozoic Birrindudu Basin of the Northern Territory and Western Australia. Additionally, the Paleo-Mesoproterozoic McArthur Basin of the Northern Territory is represented by a small number of analyses. Tests include unconfined compressive strength tests, laboratory ultrasonic measurements, single and multi-stage triaxial tests and Brazilian tensile strength tests. These datasets are a precompetitive resource that can facilitate investment decisions in frontier regions, helping to identify elements of conventional and unconventional hydrocarbon systems as well as providing essential data to assess geological storage opportunities.

Taxonomic revision of the genus Stiptognathus (Conodonta) from the Lower Ordovician of Australia and its biostratigraphical and palaeobiogeographical significance

Stiptognathus borealis from the Lower Ordovician Emanuel Formation and correlative subsurface Nambeet Formation of the Canning Basin in Western Australia is examined taxonomically. It is the type and only known species of the genus Stiptognathus, with a stratigraphical range restricted to the lower Floian (Lower Ordovician). The distribution of S. borealis suggests that this species might have inhabited a spectrum of environments, but it was palaeobiogeographically restricted to the tropical zone, possibly because of sea water temperature sensitivity. This study provides a new description of this species and redefines its constituent element types comprising a seximembrate apparatus. This is characterized by a pastinate Pa element and modified angulate Pb element. Stiptognathus borealis is morphologically most closely related to the genus Fahraeusodus. These taxa form a clade that might be phylogenetically basal to Plectodinidae and Cyatoniodontidae, which flourished in Middle and Late Ordovician times. Yong Yi Zhen [yong-yi.zhen@regional.nsw.gov.au ], Geological Survey of New South Wales, W.B. Clarke Geoscience Centre, 947-953 Londonderry Road, Londonderry, NSW 2753, Australia.

Contrasting morphology and growth habits of Frutexites in Late Devonian reef complexes of the Canning Basin, northwestern Australia.

Frutexites-like microstructures are described from the exhumed Late Devonian reef complexes of the northern Canning Basin, Western Australia. Several high-resolution imaging techniques, including X-ray microcomputerised tomography, scanning electron microscopy and X-ray fluorescence microscopy, were used to investigate morphology and composition in two samples. Three types of Frutexites-like microstructures (Types I-III) have been identified. Type I, found lining an early marine cement-filled cavity in fore-reef grainstone facies, consists of dendritic structures formed primarily of coccoid bacteria with filamentous bacteria embedded in sheets of amorphous extracellular polymeric substances (EPS). These ferromanganiferous dendrites have laminated to spheroidal textures. Types II and III are from a toe-of-slope hardground. Type II grew in a crypt between two corals, is also dendritic and composed of bacilliform and filamentous bacteria embedded in an amorphous EPS sheet. The opaqueness of these ferriferous dendrites precludes more detailed description of textures. Type III grew as branching columnar microstromatolites and is composed of entwined filaments of Girvanella, Rothpletzella and Wetheredella with Fe-enriched outer walls that generate Frutexites-like microstructures. Types I and II resemble Frutexites sensu stricto as defined by Maslov (Stromatolites, Trudy Instituta geologicheskikh nauk Akademiya nauk SSR, 1960) and are the result of the consecutive growth and permineralisation of biofilms composed of mixed bacterial communities growing in cryptic habitats. Type III superficially resembles Frutexites sensu stricto based on macroscopic field observations, however, detailed microscopic analysis reveals that it is composed of Fe-enriched tubular walls surrounded by Mn-enriched calcite.

Discussion of Yule, C.T.G., Daniell, J., Edwards, D.S., Rollet, N. & Roberts, E.M. (2023). Reconciling the onshore/offshore stratigraphy of the Canning Basin and implications for petroleum prospectivity. Australian Journal of Earth Sciences, 70(5), 691–715

Discussion of Yule, C.T.G., Daniell, J., Edwards, D.S., Rollet, N. & Roberts, E.M. (2023). Reconciling the onshore/offshore stratigraphy of the Canning Basin and implications for petroleum prospectivity. Australian Journal of Earth Sciences, 70(5), 691–715

Relationship between seismic acoustic impedance (AI) and total organic carbon (TOC) content: a case study from Australia

. Shale gas has become of interest of geoscientists globally because of its potentials to expand our energy supply. This research used well logs data and total organic carbon (TOC) data from Perth and Canning Basins, Australia. The objective of this research is to investigate source rock potential of the study area by examining the relationship between TOC content and seismic acoustic impedance (AI) derived from well log data, using regression analysis. The outcomes of this research show that for claystone/siltstone, the relationship between AI and TOC is nonlinear, while for shale the correlation is linear. However, there is no fixed equation that can be used as a standard for this linear/nonlinear relationship. Results show that for a certain type of lithology, the relationship between TOC and AI is different for different formations. This is interpreted to be caused by different depositional environment, diagenesis, mineralogical composition and different depth of burial. Findings of this study are expected to provide some new insights into the relationship between AI and TOC for various types of lithology and contribute to shale gas exploration studies.

Revision of conodont genus Protoprioniodus and its type species from the Lower Ordovician of the Canning Basin, Western Australia

Examination of the original types and abundant topotype specimens from the Emanuel Formation (Early Ordovician) and the correlative subsurface Nambeet Formation of the Canning Basin in Western Australia confirms a septimembrate species apparatus for Protoprioniodus simplicissimus, the type species of the genus. Species of Protoprioniodus are characterized by having a seximembrate or septimembrate protoramiform–protopectiniform apparatus with a distinctive basal surface well-developed between the basal margin and the basal flange in the constituent elements. The generic concept of Protoprioniodus is re-defined based on its type species and reassessment of all the species previously assigned to this genus. Protoprioniodus might be evolved in late Tremadocian (Early Ordovician) possibly from an unknown species of basal Oistodus. With five species confirmatively assigned to, Protoprioniodus is recognized as a morphologically distinctive conodont clade within family Oistodontidae and biostratigraphically useful for correlation of the uppermost Tremadocian to Middle Ordovician rocks. Protoprioniodus simplicissimus was cosmopolitan while other species seem variably restricted in palaeogeographic distribution.

Seismically constrained gravity inversions reveal magmatic and metamorphic processes at a major lithospheric boundary in northwestern Australia

Magmatic and metamorphic processes modifying the lower crust and uppermost mantle are key to understanding continental growth and evolution. However, our ability to identify and quantify such processes is challenged by inaccessibility, data sparsity, and uncertainties in defining properties at depth. As a result, knowledge of composition, metamorphic grade, and the nature of the continental crust-mantle transition is often limited. Here, we model the structure and properties of the crust and uppermost mantle between the West and North Australian Cratons to infer tectonic processes at this major lithospheric boundary. Seismically constrained 3D gravity inversions were used to estimate crustal and mantle densities and Moho depths. The application of isostatic principles and the joint interpretation of gravity, active and passive seismic models, well data, and outcrop data are used to identify and characterize anomalous masses that are otherwise unresolvable using supracrustal datasets. The results suggest a thick, dense crust with a mafic bulk composition, a high-density, reflective lower crust, and a low-density uppermost mantle beneath the southern Canning Basin. We interpret these crustal and mantle features as reflecting mafic mantle-derived magmatism and crustal anatexis related to Proterozoic-Cambrian Large Igneous Provinces. In contrast, the Proterozoic Paterson Orogen exhibits a thick, dense, high-grade metamorphic bulk crust with a felsic to intermediate composition, a high-density, low-reflectivity lower crust, and low-density uppermost mantle, inferred to result from convergent tectonics. The northern Canning Basin displays a thinner, less dense crust with an intermediate to mafic composition, and mafic, high-density, reflective lower crust, associated with mafic magma emplacement during rifting and passive margin formation. These variations in crustal structure reveal a complex interplay of Proterozoic terrane amalgamation to the cratonic margin, repeated intraplate high-volume mafic magmatic events, and rifting of the offshore basin, which have collectively shaped the deep crust and uppermost mantle in this region.

Reconciling the onshore/offshore stratigraphy of the Canning Basin and implications for petroleum prospectivity

The Canning Basin is a prospective hydrocarbon frontier basin and is unusual for having limited offshore seismic and well data in comparison with its onshore extent. In this study, seismic mapping was conducted to better resolve the continuity of 13 key stratigraphic units from onshore to offshore to delineate prospective offshore hydrocarbon-bearing units, and better understand the distribution of mafic igneous units that can compartmentalise migration pathways and influence heat flow. The offshore Canning Basin strata are poorly constrained in six wells with limited seismic coverage; hence data availability was bolstered by integrating data from the onshore portion of the basin and adjacent basins into a single 3D seismic stratigraphic model. This model integrates over 10 000 km of historical 2D seismic data and 23 exploration wells to allow mapping of key stratal surfaces. Mapped seismic horizons were used to construct isochores and regional cross-sections. Seven of the 13 units were mapped offshore for the first time, revealing that the onshore and offshore stratigraphy are similar, albeit with some minor differences, and mafic igneous units are more interconnected than previously documented whereby they may constitute a mafic magmatic province. These basin-scale maps provide a framework for future research and resource exploration in the Canning Basin. To better understand the basin’s geological evolution, tectonic history and petroleum prospectivity, additional well data are needed in the offshore Canning Basin where Ordovician strata have yet to be sampled.

Early Permian zircon ages from the P. confluens and P. pseudoreticulata spore-pollen zones in the southern Bonaparte and Canning basins, Northwestern Australia

The Pseudoreticulatispora confluens–P. pseudoreticulata spore-pollen zonal datum typically coincides with the end of widespread Permian glacial deposits in Western Australia. Although previously attributed to the mid-Sakmarian, chemical abrasion isotope dilution thermal ionisation mass spectrometry (TIMS) dating of zircons from volcanic tuffs in the Ditji Formation of the Bonaparte Basin and the Grant Group in the Canning Basin point to an Asselian age of about 295.25 Ma for this datum. All dated zircons from the Ditji Formation came from petroleum well cuttings but the accompanying palynology was mostly from sidewall cores; however, all Grant Group samples were from conventional core. TIMS dates from the Ditji Formation range in age from 295.2 to 292.7 Ma whereas the only productive tuff from the Grant Group yielded a 296.26 Ma date. By comparison, there are no zircon dates to constrain the onset of glacial deposition in Australia. The Bonaparte Basin ages overlap with those for the Edie Tuff (296.1–294.5 Ma) in Queensland’s Galilee Basin, approximately 2000 km to the southeast, which also lies close to the base of the P. pseudoreticulata Zone. To date the only fossil group within the P. confluens Zone in Western Australia to provide independent age control, albeit loosely, are goniatites from the northern Perth Basin (Uraloceras irwinense and Juresanites jacksoni) that have consistently been attributed to the Sakmarian; these require a reassessment of their affinity with Russian faunas and therefore to global stratotypes. The position of the Carboniferous–Permian boundary is elusive in Australia and will remain so until additional volcanic tuffs containing young datable zircons are found; however, spore-pollen and zircon dates from Namibia place this boundary within the P. confluens Zone.

The Ordovician System in Australia and New Zealand

Abstract The stratigraphic overview presented in this chapter substantially updates and revises the last major review of the Ordovician rocks of Australia and New Zealand published 40 years ago. In the western two-thirds of the present-day continent of Australia, Ordovician sedimentary rocks are restricted to intracratonic basins. The Canning Basin (Western Australia) and Amadeus Basin (central Australia) contain the best known Lower and Middle Ordovician shallow marine successions. The eastern third of the continent, known as the Tasmanides, comprises multiple orogens (i.e. Delamerian, Lachlan, New England, Thomson, Mossman) that formed along the convergent East Gondwana Margin. As a result, volcanic and intrusive rocks are much more common in these orogens than in the intracratonic basins. Their deep-water depositional environments span 31 graptolite biozones. Slope and basinal siliceous sedimentary rocks are constrained by a newly defined set of 12 conodont biozones, complementing the conodont biostratigraphic scheme refined for shallow-water environments from the basal boundary of the Ordovician to the latest Katian. In some places, these conodont biozones are integrated with radiometric ages from tuff interbeds (e.g. Canning Basin). Ordovician graptolitic strata in the Buller Terrane of New Zealand share palaeogeographic links with those in the Bendigo Zone of the western Lachlan Orogen.

In situ calcite U–Pb geochronology of carbonate and clastic sedimentary rocks from the Canning Basin, Western Australia

In sedimentary basins, the determination of the absolute timing of deposition and diagenetic events is a challenging yet critical parameter necessary in the reconstruction of paleo-fluid evolution and burial histories. Here we demonstrate the practical application of in situ calcite U–Pb geochronology on core samples from the Olympic 1 well in the Canning Basin of Western Australia. Using quantitative mineralogy and laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) analytical techniques, we obtained an authigenic calcite U–Pb age of 469.7 ± 4.3 Ma for limestone in the Samphire Marsh Member of the Lower Ordovician Nambeet Formation. This precise depositional age can be independently verified using zircon thermal ionisation mass spectrometry U–Pb ages of 479.4 to 470.2 Ma determined on adjacent volcanic ash beds. Further geochronology studies on calcite cements from the Lower Ordovician Fly Flat Member sandstone from the Nambeet Formation returned a U–Pb age of 365.3 ± 5.8 Ma. This is the first study to place absolute age constraints on the diagenetic event that occluded the intergranular space in a sandstone reservoir. The calcite cementation age suggests that impairment of reservoir quality in the Fly Flat Member sandstone occurred in the Late Devonian, much earlier than major petroleum charge events in the Canning Basin. The calcite U–Pb geochronometer, when combined with complementary quantitative mineralogical analysis, can build direct temporal constraints on the depositional and diagenetic processes in both carbonate and clastic sedimentary rocks in basins worldwide.

Seismic Snapshot - PESA News 167

Western Gas Secures Strategic Ashburton Land for Low Carbon Equus Gas Production Western Gas’ Equus Gas to Backfill North West Shelf and Pluto LNG APPEA Punts New Natural Gas Supply Key to WA Economy and a Cleaner Energy Future Searcher Releases Onshore East Canning Basin 2D Seismic Reprocessing for Mineral & Energy Exploration Westwood Wildcat Joins the GeoClerk Platform

Revision of the Ordovician conodont species Fahraeusodus adentatus and the new genus Pohlerodus

Fahraeusodus adentatus, the type species of Fahraeusodus, is revised based on the re-examination of the original types and a large collection of topotype specimens from the Emanuel Formation (Lower Ordovician) of the Canning Basin in Western Australia. Confirmation of a modified pastinate Pa element in the septimembrate ramiform-pectiniform apparatus of this conodont species has resulted in a redefined generic definition for Fahraeusodus. Based on this newly defined diagnosis of Fahraeusodus and its type species, all other species previously assigned to Fahraeusodus and Texania are reviewed and now placed in Pohlerodus gen. nov., which is erected herein to substitute Texania, which is a junior homonym. Yong Yi Zhen [ yong-yi.zhen@regional.nsw.gov.au ], Geological Survey of New South Wales, W.B. Clarke Geoscience Centre, 947–953 Londonderry Road, Londonderry NSW 2753, Australia.

Age and origin of the West Kimberley lamproites, Western Australia

New high precision 40Ar/39Ar ages are presented which more tightly constrain the eruption ages of the West Kimberley lamproites of northwestern Western Australia. The data show a southward progression in ages of the lamproites over a distance of ∼135 km, from ∼22.5 Ma in the northernmost lamproites of the Ellendale Field to ∼19 Ma in the Noonkanbah Field in the south, excluding the Walgidee Hill lamproite. The large (∼490 ha) zoned Walgidee Hills lamproite at the northern edge of the Noonkanbah Field is the youngest of the West Kimberley lamproites and represents a later pulse of lamproite magmatism at 17.4 Ma, >1 Ma after the main lamproite magmatism.The southward progression of lamproite ages extends across a wide swath from the Proterozoic King Leopold Orogen at the southern margin of the Kimberley Craton to the Phanerozoic Fitzroy Trough in the Canning Basin. The magmatism does not appear to be the result of the migration of a mantle plume, but more likely reflects small degrees of partial melting of old, thick, metasomatised lithosphere extending from the craton margin beneath the basin, with melting triggered by regional uplift and/or small-scale mantle convection at the craton margin. Emplacement of the lamproites likely exploited ancient trans-lithospheric structures associated with the Proterozoic orogen at the craton margin and structures associated with the formation of the Canning Basin in the Phanerozoic.

Reorganization of continent‐scale sediment routing based on detrital zircon and rutile multi‐proxy analysis

AbstractThe duration and extent of sediment routing systems are intrinsically linked to crustal‐ to mantle‐scale processes. Therefore, distinct changes in the geodynamic regime may be captured in the detrital record. This study attempts to reconstruct the sediment routing system of the Canning Basin (Western Australia) during the Early Cretaceous to decipher its depositional response to Mesozoic‐Cenozoic supercontinent dispersal. Specifically, we reconstruct source‐to‐sink relationships for the Broome Sandstone (Dampier Peninsula) and proximal modern sediments through multi‐proxy analysis of detrital zircon (U–Pb, Lu–Hf and trace elements) and detrital rutile (U–Pb and trace elements). Multi‐proxy comparison of detrital signatures and potential sources reveals that the majority of the detrital zircon and rutile grains are ultimately sourced from crystalline basement in central Australia (Musgrave Province and Arunta region) and that proximal sediment supply (i.e., Kimberley region) is negligible. However, a significant proportion of detritus might be derived from intermediate sedimentary sources in central Australia (e.g., Amadeus Basin) rather than directly from erosion of crystalline basement. Broome Sandstone data are consistent with a large‐scale drainage system with headwaters in central Australia. Contextualization with other broadly coeval drainage systems suggests that central Australia acted as a major drainage divide during the Early Cretaceous. Importantly, reorganization after supercontinent dispersal is characterized by the continuation of a sediment pathway remnant of an earlier transcontinental routing system originating in Antarctica that provided a template for Early Cretaceous drainage. Review of older Canning Basin strata implies a prolonged denudation history of central Australian lithologies. These observations are consistent with the long‐lived intracontinental tectonic activity of central Australia governing punctuated sediment generation and dispersion more broadly across Australia and emphasize the impact of deep Earth processes on sediment routing systems.

Triaxial Deformation of the Goldwyer Gas Shale at In Situ Stress Conditions—Part I: Anisotropy of Elastic and Mechanical Properties

The evolution of shale’s mechanical properties with confining pressure, temperature, and mineral composition directly influences fracture closure besides the effect of in situ stress variation across lithologies. We are the first to perform experimental study to characterize the mechanical properties of the Goldwyer gas shale formation located in the Canning Basin, Western Australia. We have performed constant strain rate multistage triaxial tests at in situ stress condition (confining pressure ≤ 22 MPa) on 15 samples of the Goldwyer gas shales with variable minerology, organic content, and heterogeneity. Deformation tests were conducted at room temperature and in drained conditions on cylindrical samples cored parallel (horizontal) and perpendicular (vertical) to the bedding plane. Both triaxial compressive strength (σTCS) and static young’s modulus E show a strong sensitivity to confining pressure and mineralogy, while only E shows a directional dependency, i.e., Eh > Ev. The internal friction coefficient µi in a plane parallel to the bedding is 0.72 ± 0.12, while it is only 0.58 ± 0.17 in the orthogonal direction. Both σTCS and E are significantly lower when larger fractions of weak mineral constituents are present (clays or organic matter). We observe that the Young’s modulus of most vertical samples is best approximated by Reuss’s bound, whereas that of horizontal samples is best approximated by Hill’s average of Voigt and Reuss bounds. The most prospective G-III unit of the Goldwyer shale formation (depth > 1510 m) is semi-brittle to brittle, making it suitable for future development.

Geoscience Poster G13: A regional strike-slip fault under the Canning Basin

Poster G13 Gravity data in the Canning Basin exhibit a northeast-trending linear feature that offsets a gravity ridge in the vicinity of the Jurgurra–Mowla Terraces with a displacement of about 30 km. The sharp displacement is aligned with similar disruptions on the Lennard Shelf to the northeast and Broome Platform to the southwest. The northeast part of the lineament also shows an anomalous offset on aeromagnetic images. However, the lineament does not correspond to fault displacement within the sedimentary succession of the Canning Basin based on seismic profiles. The geophysical responses to the linear feature vary in different areas, possibly caused by the different thickness of overlying sedimentary rocks across the basin. The lineament is interpreted as a left-lateral strike-slip fault that pre-dates the Canning Basin to account for the lack of seismic responses in the sedimentary section. This northeast-trending fault lies in the basement and might have originated during one of the younger Proterozoic to earliest Paleozoic orogenies pre-dating the Canning Basin. The northeast-oriented fault in the basement was orthogonal to the strike of the basin, thus was less likely to have significant impact on the basin deposition compared to the northwest-oriented faults, such as the Pinnacle and Fenton Fault system. However, these perpendicular features probably created a deeply seated crustal weakness near the intersection where the cluster of lamproite pipes of the Ellendale field intruded during the Miocene. To access the poster click the link on the right. To read the full paper click here