contentsNatural Hydrocarbon Seepage In Offshore Northern Perth Basin:
Evidence For An Extension Of Active Perth Basin Petroleum Systems.Nadege Rollet, Andrew Jones, Emmanuelle Grosjean, Chris Nicholson, Geoscience Australia; Jens Greinert, Royal Netherlands Institute for Sea Research; and SS052011 Survey Party.
Fig. 1. Bathymetry map of the offshore northern Perth Basin with location of GA-0332 survey track and areas (A–H).
Fig. 2. Conventional 2D seismic line hp01-102p showing recent fault movement along the Houtman Fault System, bounding the Houtman Sub-basin outboard from the Wittecarra Terrace inboard. The location of the Livet-1 well is indicated. 
Fig. 3. Integration of data over potential seepage site: multibeam bathymetry over Area H revealing pockmark (1–10 m deep and 10–100 m wide) fields, small mounds, and escarpments (up to m); A) Hydroacoustic flares detected in sidescan sonar data; B) Dark-coloured fluid on the seabed and suspended in water in video footage from the ROV; C) Carbonate blocks in video footage from the ROV. 
Fig. 4. Sub-bottom profiles showing shallow sub-surface geology above the tip of the Houtman Fault System in Area H. a) Line S0332_393 showing shallow amplitude anomalies and pockmarks above the tip of the fault; b) Line S0332_340 showing amplitude anomalies just below the location where acoustic flares were observed with the sidescan sonar.Geoscience Australia has recently completed a marine survey in the offshore northern Perth Basin off Western Australia (Jones et al., 2011a; Jones, 2011b, Upton and Jones, 2011). One of the principal aims of the survey was the collection of evidence for natural hydrocarbon seepage. The survey formed part of a regional reassessment of the basin's petroleum prospectivity in support of frontier exploration acreage Release Area W11–18. This reassessment was initiated under the Australian Government's Offshore Energy Security Program and formed part of Geoscience Australia's continuing efforts to identify a new offshore petroleum province. The offshore northern Perth Basin was identified as a basin with new frontier opportunities. New data demonstrated that proven onshore-nearshore petroleum system is also effective and widespread in the offshore (Jones et al., 2011c). Evidence for a Jurassic petroleum system was also demonstrated in the Release Area W11–18 (Jones et al., 2011c). The marine survey results provide additional support for the presence of an active petroleum system in the northern Perth Basin.
Survey rationale and data acquisition
The GA-0332 survey used the Australian Government's Marine National Facility, the RV Southern Surveyor to sample and collect data. 3473 km2 of multibeam bathymetry, 4038 line km of sub-bottom profiler, 1546 line km of sidescan sonar and echosounder data were acquired to map seafloor and water column features and characterise the shallow sub-surface sediments. A remotely operated vehicle (ROV), supplied and operated by research collaborators from the Royal Netherlands Institute for Sea Research and from the University of Ghent in Belgium, was also deployed in selected areas to observe and record evidence of seepage on the seafloor. 71 sediment grabs and 28 gravity cores were collected. Selected samples have been analysed for headspace gas, high molecular weight hydrocarbons and infaunal content for potential indicators of thermogenic hydrocarbons.
Seven areas were surveyed (A–H; Figure 1) over the Abrolhos and Houtman sub-basins and the Wittecarra Terrace. The surveyed areas include proven (drilled) oil and gas accumulations (Dunsborough and Frankland; areas B and C), a breached structure (Livet Area H), undrilled hydrocarbon prospects identified in open-file seismic interpretation reports (Callisto, Updip Batavia and Zeewyck; areas A, E and F), and areas with potential signatures of fluid seepage identified in seismic, satellite remote sensing and multibeam bathymetry data (areas D, E, F and H).
In this article we focus on Area H, in the north of the study area, where survey data identified an area of high 'seepage' potential. In this region, a previous fluid inclusion study detected palaeo-oil accumulations in Permian sandstones below the Kockatea regional seal at Livet-1 and Morangie-1 (Kempton et al., 2011). The 10 m palaeo-oil column in Livet-1 was sourced from the Hovea Member, which is immature at the well location (Grosjean et al., 2011). This result suggests that the oil was sourced from an outboard kitchen in the Houtman Sub-basin and migrated into the structure. This accumulation has been breached subsequently, either during Jurassic – Early Cretaceous extension, Valanginian breakup, margin tilt or Miocene inversion (Kempton et al., 2011).
Across Australia, compressional reactivation of normal faults since the Late Miocene to present day is linked to the collision and tectonic re-organisation of the Australian and Eurasian plates. This recent faulting is considered as one of the major causes for numerous breached hydrocarbon traps on the Northwest Shelf and could also have contributed to the leakage of a palaeo-oil column in the Livet-1 prospect in the northern Perth Basin (Kempton et al., 2011). In addition, at Livet-1 an inversion event is visible on the seafloor. The area was also selected because it overlies the Houtman Fault System, a major basin-bounding fault that separates the Houtman Sub-basin from the Wittecarra Terrace (Figure 2). Recent structural inversion along this major fault system, subsequent to the Miocene, is evident in 2D seismic data. Recent earthquakes of 3–5 magnitude have occurred in the area attesting that faults in this part of the margin are in a suitable orientation and dip to be reactivated in the current stress-field. The current stress field is roughly E–W-orientated and transpressional. Faults that strike north and dip moderately as well as fault striking east-northeast and east-southeast with shallow to steep dips have the potential to be reactivated in this stress regime (Hillis and Reynolds, 2000; Reynolds and Hillis, 2000; King et al., 2008).
A reactivation event affects the shallow sub-surface geology above the fault tip, deforming the shallow buried bottom sets of the Cenozoic clinoforms (Figure 2). An amplitude anomaly above the fault tip is also observed just below the seafloor and may indicate potential fluid migration along the fault (Figure 2). The tip of this fault (black line) correlates with the 'heads' of shallow elongate depressions mapped in the multibeam bathymetry data, suggesting that this fault has exerted some influence on the modern seafloor morphology.
Results from Area H
In survey area H, acoustic data revealed pockmarks on the seabed and numerous 'flares' in the water column. Carbonate blocks and other seafloor features were also observed in video footage collected with the ROV. These features are analogous with known hydrocarbon seepage sites in the Timor Sea and are described in more detail below.
- Flares in the water column identified with echosounder and sidescan sonar data
Numerous acoustic flares, ranging up to 50 m in height above the seafloor, were identified in the water column within Area H (Figure 3, location A). These flares represent areas of lower density than the surrounding seawater. Typically, very strong acoustic responses on echosounder sonars are created by bubbles of gas, which have a large density contrast relative to the surrounding seawater. Bubbles rising from the seafloor, such as in a natural gas seep, show up as 'flares'. Fish also contain a bubble in their swim bladder and also have a strong acoustic response, making interpretations between gas seeps and fish problematic. During this survey the vertical geometries of the observed flares are more consistent with bubbles rising from the seafloor than a school of fish. Similar acoustic flares were observed during a previous survey where Geoscience Australia found evidence of thermogenic gas seep in the Timor Sea, near the Cornea oil and gas field (Rollet et al., 2006).
- Dark-coloured fluid observed on ROV video footage
Underwater video footage was acquired using a ROV at five sites within the survey area, including parts of area H where the flares were observed. While no active seepage was observed, the footage revealed a dark-coloured viscous fluid resting on the seafloor; roughly 2 km away from the acoustic flares (Figure 3, location B). The fluid appears as a metre-long elongated feature. Possible explanations for the origin of this fluid are: 1) biological (eg. cephalopod ink), 2) oil sourced from anthropogenic activities (eg. bunker oil from a ship), 3) oil from natural hydrocarbon seepage. Video footage of the dark-coloured fluid is available from the Geoscience Australia website (http://www.ga.gov.au/energy/projects/perth-petroleum.html). Unfortunately, sampling of this fluid was not possible.
- Pockmarks, concretions and high-backscatter on seafloor recognised on multibeam bathymetry and sidescan sonar data
Various seabed features were found in Area H including many pockmarks, which form circular depressions on the seafloor between 1–10 m deep and 10–200 m wide (Figure 3). These features are known to occur at hydrocarbon seepage sites where they form as fluid or gas seeps from the seafloor, carrying sediment into the water column and leaving behind a seafloor depression (Judd and Hovland, 2007).
Seabed mounds between 3–10 m high and 100-200 m wide were also mapped in the multibeam data. ROV video footage showed these mounds to be carbonate blocks on the seafloor (Figure 3, location C). The coupling of sulphate reduction with methane oxidation at hydrocarbon seep sites can produce authigenic carbonates, although it is not clear if this is the source of the carbonate in Area H.
A major NW-SE trending seafloor incision, up to 50 m deep, 700 m wide, 15 km long, and parallel to the shelf break was observed in the northern part of Area H. It correlates with the break of slope (Figure 2). Bed forms, 5 m high and 500 m long, are also observed in the south part of Area H, on the edge of a palaeo-channel, revealing bottom current activity.
- Shallow sub-surface features observed in sub-bottom profiler data
The sub-bottom profiler data have a penetration of up to 70 ms two-way-time (TWT) below the seafloor, providing a good resolution image of the shallow sub-surface. Shallow faults affecting the seafloor morphology and shallow amplitude anomalies are observed in the sub-bottom profile data from Area H (Figure 4). These features are located above the tip of the recently reactivated basin bounding fault between the Houtman Sub-basin and Wittecarra Terrace (Figures 2 and 3).
- Sediment sample results
Within Area H, six gravity cores were collected and sub-sampled at one-metre intervals for head-space gas and high-molecular weight hydrocarbon analysis. Interstitial gas data revealed background levels for C1–C5 gases with methane concentrations ranging from 1 to 3 ppmV. The composition of high-molecular weight hydrocarbons (> C12) was dominated by recently deposited organic matter and thermogenic hydrocarbons were not detected. The lack of geochemical evidence for migrated gas in the gravity cores may result from lack of spatial resolution in attempting to locate and sample potential seep sites, or the poor core recovery and short core penetration depth (<3 m). A minimum penetration of 6 m for core sediments was shown to be necessary for the detection of a thermogenic signal in areas of microseepage (Abrams et al., 2001). Analysis of high-molecular weight hydrocabons in the seabed grabs is currently underway in Geoscience Australia's laboratories.
The integration of data acquired during the marine survey could be indicative of natural hydrocarbon seepage. However, it is also noted that seepage of other naturally occurring fluids such as ground water or carbon dioxide could result in similar observations. The lack of positive geochemical results thus far does not preclude a seepage interpretation, as this is consistent with a lack of geochemical seepage signatures in core and grab samples from the Timor Sea, where acoustic flares and carbonate blocks were observed over deep-seated seismic features (Rollet et al., 2006).
Summary
The survey results show a series of features consistent with known hydrocarbon seeps in other areas of the Northwest Shelf over a recently reactivated fault and a palaeo-fluid migration pathway from the Houtman Sub-basin to the Wittecarra Terrace. These features include amplitude anomalies in the shallow strata; raised, high-backscatter regions and pockmarks on the seafloor; and hydroacoustic flares identified with the sidescan sonar. The ROV underwater video footage did not observe active hydrocarbon seepage (ie. bubbles) but identified a dark-coloured fluid in 500 m water depth proximal to the sidescan flares. A natural hydrocarbon seepage interpretation for this part of the offshore northern Perth Basin is not conclusive but the correlation of several indicators is significant.
Natural oil seepage along the Houtman Fault System would suggest that hydrocarbons are reutilising palaeo-fluid migration pathways in the vicinity of the Houtman Fault System. If this is the case, intact traps along recently inverted structures could still be receiving and accumulating hydrocarbons.
References
Abrams, M.A., Segall, M.P. & Burtell, S.G., 2001. Best Practices for Detecting, Identifying and Characterizing Near-Surface Migration of Hydrocarbons within Marine Sediments. In: Offshore Technology Conference, Houston TX. Proceedings Volume, OTC Paper 13039.
Grosjean, E., Boreham, C.J., Jones, A., Kennard, J., Mantle, D. & Jorgensen, D., 2011. Geochemical study significantly extends the distribution of effective basal Kockatea Shale source rocks in the offshore northern Perth Basin. PESA News Resources, 115, Dec/Jan WA Supplement.
Hillis R.R. & S.D. Reynolds, 2003. In situ stress field of Australia. Geological Society of Australia Special Publication, 22 and Geological Society of America Special Papers, 372, 49–58.
Jones, A., 2011a. Early results from northern Perth Basin seepage survey. AusGeoNews InBrief 104, http://www.ga.gov.au/ausgeonews/ausgeonews201112/inbrief.jsp#inbrief1
Jones A., Jorgensen D., Hackney R., Nicholson C., 2011b. Hydrocarbon potential of the offshore northern Perth Basin. AusGeo News 103 (September 2011): http://www.ga.gov.au/ausgeonews/ausgeonews201109/hydrocarbon.jsp
Jones A.T., Kennard J.M., Nicholson C.J., Bernardel G., Mantle D., Grosjean E., Boreham C., Jorgensen D.C. & Robertson D., 2011c. New exploration opportunities in the offshore northern Perth Basin. The APPEA Journal 51.
Judd, A.G. & Hovland, M., 2007. Seabed fluid flow: Impact on geology, biology and the marine environment. Cambridge Iniversity Press, Cambridge, 475pp.
Kempton R., Gong S., Kennard J., Volk H., Mills D., Eadington P. & Liu K., 2011. Detection of palaeo-oil columns in the offshore northern Perth Basin: Extension of the effective Permo-Triassic Charge System. The APPEA Journal 51.
King, R.C., Hillis, R.R. & Reynolds, S.D., 2008. In situ stresses and natural fractures in the northern Perth Basin, Australia. Australian Journal of Earth Sciences 55, 685–701.
Reynolds, S.D. & Hillis, R.R, 2000. The in situ stress field of the Perth Basin, Australia. Geophysical Research Letters, 27(20), 3421–3424.
Rollet, N., Logan, G.A., Kennard, J.M., O'Brien, P.E., Jones, A.T. & Sexton, M., 2006. Characterisation and correlation of active hydrocarbon seepage using geophysical data sets: An example from the tropical, carbonate Yampi Shelf, Northwest Australia. Marine and Petroleum Geology, 23, 145–164.
Upton, D. & Jones, A., 2011. Seepage evidence boost for Perth Basin ENP, energynewspremium.net, 23 December 2011.
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Geoscience Australia has recently completed a marine survey in the offshore northern Perth Basin off Western Australia (Jones et al., 2011a; Jones, 2011b, Upton and Jones, 2011). One of the principal aims of the survey was the collection of evidence for natural hydrocarbon seepage. The survey formed part of a regional reassessment of the basin's petroleum prospectivity in support of frontier exploration acreage Release Area W11–18. This reassessment was initiated under the Australian Government's Offshore Energy Security Program and formed part of Geoscience Australia's continuing efforts to identify a new offshore petroleum province. The offshore northern Perth Basin was identified as a basin with new frontier opportunities. New data demonstrated that proven onshore-nearshore petroleum system is also effective and widespread in the offshore (Jones et al., 2011c). Evidence for a Jurassic petroleum system was also demonstrated in the Release Area W11–18 (Jones et al., 2011c). The marine survey results provide additional support for the presence of an active petroleum system in the northern Perth Basin.
Survey rationale and data acquisition
The GA-0332 survey used the Australian Government's Marine National Facility, the RV Southern Surveyor to sample and collect data. 3473 km2 of multibeam bathymetry, 4038 line km of sub-bottom profiler, 1546 line km of sidescan sonar and echosounder data were acquired to map seafloor and water column features and characterise the shallow sub-surface sediments. A remotely operated vehicle (ROV), supplied and operated by research collaborators from the Royal Netherlands Institute for Sea Research and from the University of Ghent in Belgium, was also deployed in selected areas to observe and record evidence of seepage on the seafloor. 71 sediment grabs and 28 gravity cores were collected. Selected samples have been analysed for headspace gas, high molecular weight hydrocarbons and infaunal content for potential indicators of thermogenic hydrocarbons.
Seven areas were surveyed (A–H; Figure 1) over the Abrolhos and Houtman sub-basins and the Wittecarra Terrace. The surveyed areas include proven (drilled) oil and gas accumulations (Dunsborough and Frankland; areas B and C), a breached structure (Livet Area H), undrilled hydrocarbon prospects identified in open-file seismic interpretation reports (Callisto, Updip Batavia and Zeewyck; areas A, E and F), and areas with potential signatures of fluid seepage identified in seismic, satellite remote sensing and multibeam bathymetry data (areas D, E, F and H).
In this article we focus on Area H, in the north of the study area, where survey data identified an area of high 'seepage' potential. In this region, a previous fluid inclusion study detected palaeo-oil accumulations in Permian sandstones below the Kockatea regional seal at Livet-1 and Morangie-1 (Kempton et al., 2011). The 10 m palaeo-oil column in Livet-1 was sourced from the Hovea Member, which is immature at the well location (Grosjean et al., 2011). This result suggests that the oil was sourced from an outboard kitchen in the Houtman Sub-basin and migrated into the structure. This accumulation has been breached subsequently, either during Jurassic – Early Cretaceous extension, Valanginian breakup, margin tilt or Miocene inversion (Kempton et al., 2011).
Across Australia, compressional reactivation of normal faults since the Late Miocene to present day is linked to the collision and tectonic re-organisation of the Australian and Eurasian plates. This recent faulting is considered as one of the major causes for numerous breached hydrocarbon traps on the Northwest Shelf and could also have contributed to the leakage of a palaeo-oil column in the Livet-1 prospect in the northern Perth Basin (Kempton et al., 2011). In addition, at Livet-1 an inversion event is visible on the seafloor. The area was also selected because it overlies the Houtman Fault System, a major basin-bounding fault that separates the Houtman Sub-basin from the Wittecarra Terrace (Figure 2). Recent structural inversion along this major fault system, subsequent to the Miocene, is evident in 2D seismic data. Recent earthquakes of 3–5 magnitude have occurred in the area attesting that faults in this part of the margin are in a suitable orientation and dip to be reactivated in the current stress-field. The current stress field is roughly E–W-orientated and transpressional. Faults that strike north and dip moderately as well as fault striking east-northeast and east-southeast with shallow to steep dips have the potential to be reactivated in this stress regime (Hillis and Reynolds, 2000; Reynolds and Hillis, 2000; King et al., 2008).
A reactivation event affects the shallow sub-surface geology above the fault tip, deforming the shallow buried bottom sets of the Cenozoic clinoforms (Figure 2). An amplitude anomaly above the fault tip is also observed just below the seafloor and may indicate potential fluid migration along the fault (Figure 2). The tip of this fault (black line) correlates with the 'heads' of shallow elongate depressions mapped in the multibeam bathymetry data, suggesting that this fault has exerted some influence on the modern seafloor morphology.
Results from Area H
In survey area H, acoustic data revealed pockmarks on the seabed and numerous 'flares' in the water column. Carbonate blocks and other seafloor features were also observed in video footage collected with the ROV. These features are analogous with known hydrocarbon seepage sites in the Timor Sea and are described in more detail below.
- Flares in the water column identified with echosounder and sidescan sonar data
Numerous acoustic flares, ranging up to 50 m in height above the seafloor, were identified in the water column within Area H (Figure 3, location A). These flares represent areas of lower density than the surrounding seawater. Typically, very strong acoustic responses on echosounder sonars are created by bubbles of gas, which have a large density contrast relative to the surrounding seawater. Bubbles rising from the seafloor, such as in a natural gas seep, show up as 'flares'. Fish also contain a bubble in their swim bladder and also have a strong acoustic response, making interpretations between gas seeps and fish problematic. During this survey the vertical geometries of the observed flares are more consistent with bubbles rising from the seafloor than a school of fish. Similar acoustic flares were observed during a previous survey where Geoscience Australia found evidence of thermogenic gas seep in the Timor Sea, near the Cornea oil and gas field (Rollet et al., 2006).
- Dark-coloured fluid observed on ROV video footage
Underwater video footage was acquired using a ROV at five sites within the survey area, including parts of area H where the flares were observed. While no active seepage was observed, the footage revealed a dark-coloured viscous fluid resting on the seafloor; roughly 2 km away from the acoustic flares (Figure 3, location B). The fluid appears as a metre-long elongated feature. Possible explanations for the origin of this fluid are: 1) biological (eg. cephalopod ink), 2) oil sourced from anthropogenic activities (eg. bunker oil from a ship), 3) oil from natural hydrocarbon seepage. Video footage of the dark-coloured fluid is available from the Geoscience Australia website (http://www.ga.gov.au/energy/projects/perth-petroleum.html). Unfortunately, sampling of this fluid was not possible.
- Pockmarks, concretions and high-backscatter on seafloor recognised on multibeam bathymetry and sidescan sonar data
Various seabed features were found in Area H including many pockmarks, which form circular depressions on the seafloor between 1–10 m deep and 10–200 m wide (Figure 3). These features are known to occur at hydrocarbon seepage sites where they form as fluid or gas seeps from the seafloor, carrying sediment into the water column and leaving behind a seafloor depression (Judd and Hovland, 2007).
Seabed mounds between 3–10 m high and 100-200 m wide were also mapped in the multibeam data. ROV video footage showed these mounds to be carbonate blocks on the seafloor (Figure 3, location C). The coupling of sulphate reduction with methane oxidation at hydrocarbon seep sites can produce authigenic carbonates, although it is not clear if this is the source of the carbonate in Area H.
A major NW-SE trending seafloor incision, up to 50 m deep, 700 m wide, 15 km long, and parallel to the shelf break was observed in the northern part of Area H. It correlates with the break of slope (Figure 2). Bed forms, 5 m high and 500 m long, are also observed in the south part of Area H, on the edge of a palaeo-channel, revealing bottom current activity.
- Shallow sub-surface features observed in sub-bottom profiler data
The sub-bottom profiler data have a penetration of up to 70 ms two-way-time (TWT) below the seafloor, providing a good resolution image of the shallow sub-surface. Shallow faults affecting the seafloor morphology and shallow amplitude anomalies are observed in the sub-bottom profile data from Area H (Figure 4). These features are located above the tip of the recently reactivated basin bounding fault between the Houtman Sub-basin and Wittecarra Terrace (Figures 2 and 3).
- Sediment sample results
Within Area H, six gravity cores were collected and sub-sampled at one-metre intervals for head-space gas and high-molecular weight hydrocarbon analysis. Interstitial gas data revealed background levels for C1–C5 gases with methane concentrations ranging from 1 to 3 ppmV. The composition of high-molecular weight hydrocarbons (> C12) was dominated by recently deposited organic matter and thermogenic hydrocarbons were not detected. The lack of geochemical evidence for migrated gas in the gravity cores may result from lack of spatial resolution in attempting to locate and sample potential seep sites, or the poor core recovery and short core penetration depth (<3 m). A minimum penetration of 6 m for core sediments was shown to be necessary for the detection of a thermogenic signal in areas of microseepage (Abrams et al., 2001). Analysis of high-molecular weight hydrocabons in the seabed grabs is currently underway in Geoscience Australia's laboratories.
The integration of data acquired during the marine survey could be indicative of natural hydrocarbon seepage. However, it is also noted that seepage of other naturally occurring fluids such as ground water or carbon dioxide could result in similar observations. The lack of positive geochemical results thus far does not preclude a seepage interpretation, as this is consistent with a lack of geochemical seepage signatures in core and grab samples from the Timor Sea, where acoustic flares and carbonate blocks were observed over deep-seated seismic features (Rollet et al., 2006).
Summary
The survey results show a series of features consistent with known hydrocarbon seeps in other areas of the Northwest Shelf over a recently reactivated fault and a palaeo-fluid migration pathway from the Houtman Sub-basin to the Wittecarra Terrace. These features include amplitude anomalies in the shallow strata; raised, high-backscatter regions and pockmarks on the seafloor; and hydroacoustic flares identified with the sidescan sonar. The ROV underwater video footage did not observe active hydrocarbon seepage (ie. bubbles) but identified a dark-coloured fluid in 500 m water depth proximal to the sidescan flares. A natural hydrocarbon seepage interpretation for this part of the offshore northern Perth Basin is not conclusive but the correlation of several indicators is significant.
Natural oil seepage along the Houtman Fault System would suggest that hydrocarbons are reutilising palaeo-fluid migration pathways in the vicinity of the Houtman Fault System. If this is the case, intact traps along recently inverted structures could still be receiving and accumulating hydrocarbons.
References
Abrams, M.A., Segall, M.P. & Burtell, S.G., 2001. Best Practices for Detecting, Identifying and Characterizing Near-Surface Migration of Hydrocarbons within Marine Sediments. In: Offshore Technology Conference, Houston TX. Proceedings Volume, OTC Paper 13039.
Grosjean, E., Boreham, C.J., Jones, A., Kennard, J., Mantle, D. & Jorgensen, D., 2011. Geochemical study significantly extends the distribution of effective basal Kockatea Shale source rocks in the offshore northern Perth Basin. PESA News Resources, 115, Dec/Jan WA Supplement.
Hillis R.R. & S.D. Reynolds, 2003. In situ stress field of Australia. Geological Society of Australia Special Publication, 22 and Geological Society of America Special Papers, 372, 49–58.
Jones, A., 2011a. Early results from northern Perth Basin seepage survey. AusGeoNews InBrief 104, http://www.ga.gov.au/ausgeonews/ausgeonews201112/inbrief.jsp#inbrief1
Jones A., Jorgensen D., Hackney R., Nicholson C., 2011b. Hydrocarbon potential of the offshore northern Perth Basin. AusGeo News 103 (September 2011): http://www.ga.gov.au/ausgeonews/ausgeonews201109/hydrocarbon.jsp
Jones A.T., Kennard J.M., Nicholson C.J., Bernardel G., Mantle D., Grosjean E., Boreham C., Jorgensen D.C. & Robertson D., 2011c. New exploration opportunities in the offshore northern Perth Basin. The APPEA Journal 51.
Judd, A.G. & Hovland, M., 2007. Seabed fluid flow: Impact on geology, biology and the marine environment. Cambridge Iniversity Press, Cambridge, 475pp.
Kempton R., Gong S., Kennard J., Volk H., Mills D., Eadington P. & Liu K., 2011. Detection of palaeo-oil columns in the offshore northern Perth Basin: Extension of the effective Permo-Triassic Charge System. The APPEA Journal 51.
King, R.C., Hillis, R.R. & Reynolds, S.D., 2008. In situ stresses and natural fractures in the northern Perth Basin, Australia. Australian Journal of Earth Sciences 55, 685–701.
Reynolds, S.D. & Hillis, R.R, 2000. The in situ stress field of the Perth Basin, Australia. Geophysical Research Letters, 27(20), 3421–3424.
Rollet, N., Logan, G.A., Kennard, J.M., O'Brien, P.E., Jones, A.T. & Sexton, M., 2006. Characterisation and correlation of active hydrocarbon seepage using geophysical data sets: An example from the tropical, carbonate Yampi Shelf, Northwest Australia. Marine and Petroleum Geology, 23, 145–164.
Upton, D. & Jones, A., 2011. Seepage evidence boost for Perth Basin ENP, energynewspremium.net, 23 December 2011.
