Area Summary L12-14 - Department of Mines and Petroleum

Government of Western Australia 

Department of Mines and Petroleum 

GEOLOGY AND PETROLEUM PROSPECTIVITY 

OF STATE ACREAGE RELEASE AREA L12-14, 

SOUTHERN PERTH BASIN, WESTERN AUSTRALIA 

by 

Geological Survey of Western Australia 

Perth 2012

MINISTER FOR MINES AND PETROLEUM 

Hon. Norman Moore MLC 

DIRECTOR GENERAL, DEPARTMENT OF MINES AND PETROLEUM 

Richard Sellers 

EXECUTIVE DIRECTOR, GEOLOGICAL SURVEY OF WESTERN AUSTRALIA 

Rick Rogerson 

REFERENCE 

The recommended reference for this publication is: 

Geological Survey of Western Australia 2012, Geology and petroleum prospectivity of State Acreage Release Area L12-14, 

Southern Perth Basin, Western Australia: Geological Survey of Western Australia, 9p. 

National Library of Australia Card Number and ISBN 978-1-74168-461-2 

Grid references in this publication refer to the Geocentric Datum of Australia 1994 (GDA94). Locations mentioned 

in the text are referenced using Map Grid Australia (MGA) coordinates, Zone 51. All locations are quoted to at 

least the nearest 100 m. 

Published 2012 by Geological Survey of Western Australia 

This non-series book is published in digital format (PDF), as part of a digital dataset on CD, and is available online at 

. 

Further details of geological publications and maps produced by the Geological Survey of Western Australia 

are available from: 

Information Centre 

Department of Mines and Petroleum 

100 Plain Street 

EAST PERTH, WESTERN AUSTRALIA 6004 

Telephone: +61 8 9222 3459 Facsimile: +61 8 9222 3444 

http://www.dmp.wa.gov.au/GSWApublications

Contents 

Abstract ..................................................................................................................................................................1 

Introduction ............................................................................................................................................................1 

Location and infrastructure .............................................................................................................................1 

Topography .....................................................................................................................................................5 

Wells and seismic coverage ....................................................................................................................................5 

Regional geology and prospectivity .......................................................................................................................5 

Stratigraphy .....................................................................................................................................................6 

Permian ....................................................................................................................................................6 

Triassic .....................................................................................................................................................7 

Jurassic .....................................................................................................................................................7 

Cretaceous ................................................................................................................................................7 

Conclusions ............................................................................................................................................................9 

References ..............................................................................................................................................................9 

Figures 

1. Location of State Acreage Release Area L12-14 .........................................................................................2 

2. Schematic geological cross-section of the Bunbury Trough ........................................................................3 

3. Seismic coverage, highways, railways, and locations of the GSWA water and hydrogeological 

boreholes ......................................................................................................................................................4 

4. Comparative stratigraphy of the northern and southern parts of the onshore Perth Basin ...........................8 

Tables 

1. Petroleum wells up to 35 km south of State Acreage Release Area L12-14 and within the 

Bunbury Trough ...........................................................................................................................................6 

iii

Geology and petroleum prospectivity 

of State Acreage Release Area L12-14 

Southern Perth Basin, Western Australia 

by 

Geological Survey of Western Australia 

Abstract 

State Acreage Release Area L12-14 covers about 10.5 graticular blocks (716.8 km 2 ) of the northern part of the 

Bunbury Trough with excellent access to infrastructure. The area spans the Swan Coastal Plain to the Whicher 

Range, and is bounded by the Darling Fault to the east. There are no petroleum exploration wells within the area 

and the seismic coverage is sparse. Fair to good gas shows are known from several wells within the Bunbury Trough 

to the south of the area, including Wonnerup 1, which is the closest. The Whicher Range Gasfield is also 30 km 

south of this well. The Permian section is estimated to be up to 6.5 km thick in the area, and the top of the Sue Coal 

Measures varies from a depth of 4200 m in the southwest to 8200 m in the northeast. The Lower Cretaceous – Upper 

Jurassic section gently dips eastward and becomes thicker toward the Darling Fault. Various trapping mechanisms 

are possible, although mature source rocks younger than Permian are unlikely to be present. The main risks are 

likely to be reservoir quality and trap integrity. 

KEYWORDS: State Acreage Release, Bunbury Trough, Southern Perth Basin, Western Australia, Petroleum 

prospects, tight gas 

Introduction 

The Perth Basin covers about 100 000 km 2 and contains 

a number of proven Permian and Mesozoic petroleum 

systems. The onshore part of the basin covers approximately 

45 000 km 2 and extends 650 km along the southwest coast 

of Western Australia, mainly to the south of Geraldton 

(Hocking, 1994). In total, 300 wells have been drilled in 

the basin, onshore and offshore (as of December 2011), 

resulting in the discovery of 31 hydrocarbon fields and 

several significant accumulations (GSWA, 2011), mostly 

within the northern onshore part of the basin. 

The southern Perth Basin extends from the Harvey Ridge 

southwards across the south coast of the State, consisting 

of the Bunbury Trough and the Vasse Shelf (Figs 1 and 2; 

Crostella and Backhouse, 2000, fig. 4). Hydrocarbon 

shows have been reported from several wells within 

the Bunbury Trough, including those close to the State 

Acreage Release Area L12-14 (Fig. 2). Wonnerup 1 is the 

closest well. It was drilled on the crest of a north–south 

trending anticline (Crostella and Backhouse, 2000, figs 62 

and 69). This structure extends northward into the Release 

Area, although there were no successful mechanical tests. 

The location has been ranked as the Wonnerup prospect 

(Fig. 2; Ferdinando and Dedman, 2003). 

1 

The only major discovery within the Bunbury Trough has 

been the Whicher Range Gasfield, where significant gas 

flows from the Upper Permian Willespie Formation were 

encountered in five wells (Table 1; Sharif, 2007). This is 

a much larger structure than the one at the Wonnerup 1 

site, and it is estimated to contain an original gas in place 

volume of up to 142.5 Gm 3 (5 Tcf), although attempts to 

develop the field have been unsuccessful so far. A major 

research project has analyzed causes of failure, and has 

proposed new drilling methods and approaches to reservoir 

stimulation (WA:ERA, 2012). 

Location and infrastructure 

State Acreage Release Area L12-14 (716.8 km 2 ) covers 

almost 10.5 graticular blocks within the poorly explored 

northern part of the Bunbury Trough, nearly 170 km 

south of Perth (Figs 1–3). The port city of Bunbury is 

partially within the Release Area, and Busselton is about 

13 km to the southwest (Fig. 3). The Dampier–Bunbury 

Gas Pipeline extends to 7 km north of the area, and the 

BP Kwinana Refinery is 30 km south of Perth. Rising 

demand and proximity to potential industrial consumers 

could facilitate commercialization of even a relatively 

small discovery.

GSWA 

32°00' 

33°00' 

34°00' 

SNA58 

115°00' 

Yallingup Shelf 

Vlaming Sub-basin 

Eastern Mentelle 

Sub-basin 

Leeuwin 

Inlier 

Augusta 

Vasse 

Shelf 

Busselton 

Dunsborough 

Busselton 

Fault 

Vasse 

Shelf 

Harvey Ridge 

Bunbury 

Whicher 

Range 

Gasfield 

Fault 

Darradup Fault 

PERTH 

Mandurah 

Terrace 

Bunbury 

Trough 

Dampier–Bunbury Gas 

Pipeline 

L12-14 

Darling Fault 

Esperance 

Shelf 

116°00' 

2 

Darling Fault 

YILGARN 

CRATON 

Collie 

Sub-basin 

17.07.12 

Figure 1. Location of State Acreage Release Area L12-14 

Offshore/onshore 

Phanerozoic basin 


basement 

Acreage Release Area 


Tectonic boundary 

Coastline 

Fault 

Pipeline 

Town 

Petroleum exploration 

well 

50 km

10 km 

Geology and petroleum prospectivity of State Acreage Release Area L12-14, Southern Perth Basin 

D D' 

LEEUWIN 

INLIER 

0 

Kilometres 

Dunsborough 

Fault 

2 

4 

6 

8 

VASSE SHELF 

34°00' 

Cretaceous 

Jurassic 

Triassic 

Eastern Mentelle 

Sub-basin 

Yallingup 

Shelf 

Chapman Hill 1 

(projected) 

Busselton Fault 

Vertical exaggeration = 2.5 

D 

Permian 

Basement 

SNA57 23.07.12 



Onshore/offshore 

basement 



BUNBURY TROUGH 

Whicher Range 1 

Sabina River 1 (projected) Warnbro Group and 

(projected) 

Bunbury Basalt 

Sabina Sandstone 

50 km 

3 

Main unconformity 

115°00' 116°00' 

Leeuwin 

Inlier 

Augusta 

Gas discovery 

Vasse 

Shelf 

Busselton 

Bunbury 

Sabina River 1 


Dunsborough Fault 

Vasse 

Shelf 

Busselton 

Sabina 

Fault 

Fault 

Sub-basin boundary 

Bunbury 

Trough 


Wonnerup 1 

Whicher 

Range 

Gasfield 

Darradup 

Fault 

Petroleum exploration well, dry 

Other petroleum exploration wells 

Town 

Cattamarra Coal Measures 

Lesueur Sandstone 

Stockton Group 

Sue Group 

Fault 

(717 km ) 

2 

Darling Fault 

D’ 

YILGARN 

CRATON 

Wonnerup 

prospect 

Section line 

D D’ 

Gasfield 

YarragadeeYILGARN 

Formation CRATON 

Figure 2. Schematic geological cross-section of the Bunbury Trough (from Crostella and Backhouse, 2000; Ferdinando and 

Dedman, 2003) 

Darling Fault

GSWA 

33°15’ 

33°30’ 

BUSSELTON 

33°45’ 


SNA59 

Vasse 

Shelf 

Vlaming Sub-basin 

Wonnerup 



Basement 

115°30' 

Wonnerup 1 

5 

Ruabon 

Sabina River 1 

Whicher 

Range 

Gasfield 



Bunbury 

Trough 

BUNBURY 

1 2 

MR68-AL 

Capel 

Binningup 

MR68-AM 

10 km 

Tectonic boundary 

Coastline 

Fault 

Seismic line 

Highway 

Railway 

Pipeline 

4 


A61-049 1 

2 

MR68-AN 

3 

H69-Y 

6 7 8 

Railway 

Bunbury 

Trough 

115°45' 

Jarrahwood 

Mandurah 

Terrace 

Harvey Ridge 

Dampier– 

Bunbury 

Gas Pipeline 

Roelands 

Burekup 

3 4 

Dardanup 

GSWA 

Donnybrook 

DNB 3 

Donnybrook 

Quindalup Line 

Newlands 

YILGARN 

CRATON 

4 

Boyanup Line 

GSWA 

Boyanup Donnybrook 

DNB 4 

Gwindinup GSWA 

Donnybrook 

DNB 5 

9 

DARLING FAULT 

DARLING 

FAULT 

Picton Line 

Kirup 

17.07.12 

Town 

Whicher Range 1–5 wells 

Petroleum exploration well, dry 

Water bore 

Hydrogeological bore 

Figure 3. Seismic coverage, highways, railways, and locations of the GSWA water and hydrogeological 

boreholes (from Commander, 1982)

Topography 

Release Area L12-14 extends eastward over a coastal 

system of dunes, limestone ridges, and wetlands, and 

spans the relatively featureless Swan Coastal Plain, which 

is bounded by the Whicher Range in the eastern and 

southeastern parts of the area. The range contains eroded 

Lower Cretaceous rocks, rising to a maximum elevation of 

160 m, and is bounded by the Whicher Scarp. The scarp is 

a curved erosional feature extending parallel to the coast 

about 15 km inland. The more prominent Darling Scarp 

is located farther east and joins the Whicher Range to the 

northeast of the area (Freeman and Donaldson, 2006). The 

Whicher Range is a part of the Blackwood Plateau, covered 

with native eucalypt forest. The Darling Scarp is associated 

with the position of the Darling Fault, which defines the 

eastern boundary of the Perth Basin (Figs 1 and 2). 

Wells and seismic coverage 

Twelve deep (>1000 m) stratigraphic and exploration 

wells have been drilled within the Bunbury Trough, all to 

the south of the Release Area (Table 1). Fair to good gas 

shows were encountered within the Willespie Formation 

in most wells, including Sabina River 1. The latter 

was drilled 7 km southwest of Wonnerup 1 to test the 

hydrocarbon potential of Permian sandstones within the 

Sue Group, though the well may not have tested a valid 

trap (Crostella and Backhouse, 2000). 

Some stratigraphic data are available from hydrogeological 

bores within the Release Area (Fig. 3; Commander, 1982). 

Four of these are between 1000 m and 1200 m deep. Five 

others are located close to the southern border of the area, 

four of which are over 1000 m deep (Wharton, 1981). 

Several of the bores appear to have terminated within the 

Cattamarra Coal Measures, although only two (Q2 and 

Q3) intersected the Sue Group. They are located to the 

west of the Wirring Fault in the Vasse Shelf, between 10 

and 15 km west of Busselton (Wharton, 1981). 

Seismic coverage is sparse, except for the southwestern 

part of the Release Area (Fig. 3). Line H69-7 (Harvey 

SS, 1969) extends into the Release Area from the north 

and terminates at its southern border. Line A61-049 

(Ambergate SS, 1980–81) also extends from southwest 

into the area. Three lines of the Margaret River seismic 

survey (1968) lie entirely within the area. From north to 

south, these are MR68-AM, MR68-AL, and MR68-AN. 

The quality of vintage data can be an issue for effective 

exploration (Luck, 1990; WA:ERA, 2012), although 

reprocessing may significantly improve the data quality. 

Regional geology and 

prospectivity 

The Bunbury Trough is an asymmetrical full-graben, 

nearly 150 km long and up to 50 km wide, extending 

offshore (Fig. 2). It is tilted toward the east across a series 

of longitudinal normal faults between its bounding faults, 


5 

the Darling and the Busselton Faults (Iasky, 1993, fig. 10). 

The Darling Fault has an estimated cumulative throw of 

up to about 11 km in the eastern part of the Release Area 

(Iasky, 1993). It has had a longer history of reactivation 

than the Busselton Fault, probably going back to early 

Proterozoic (Wilde and Nelson, 2001). The Darling Fault 

has also exerted fundamental control on the development 

of the Perth Basin and its pattern of subsidence (Dentith 

et al., 1994). By comparison, the Busselton Fault is a 

Middle–Late Mesozoic normal fault. 

The structural configuration of the Perth Basin is a 

product of a multi-phase process of oblique rifting, which 

commenced in the Early Permian and terminated with the 

breakup of Australia from Greater India during the Early 

Cretaceous (Harris, 1994). In the southern Perth Basin, 

two phases of transtension and transpression followed by 

another phase of extension have been recognized between 

the Dunsborough and the Darling Faults (Iasky et al., 

1991; Iasky, 1993, fig. 14). In the first phase, right-lateral 

movement along the Darling Fault along with northeast– 

southwest compression resulted in north-northwest 

trending folds during the Late Permian to the Early 

Triassic. In the second phase, left-lateral movement along 

the Dunsborough Fault took place along with northwest– 

southeast compression during the Jurassic. Finally, normal 

faulting along the Darling and the Dunsborough Faults 

and right-lateral movement along the Harvey Ridge led 

to continental breakup during the Early Cretaceous. 

Therefore, wrench-induced en echelon folds — such as 

those drilled in the Whicher Range Gasfield and Wonnerup 

1 (Crostella and Backhouse, 2000) — may have been 

dissected by the dominantly extensional phase of faulting 

during the Early Cretaceous. 

Folding may have been augmented along the Bunbury 

Trough by the presence of two rigid crystalline blocks 

to the east and west (Iasky, 1993). The Leeuwin Inlier 

extends northward offshore and joins the Southern Turtle 

Dove Ridge, which defines the western boundary of the 

central Perth Basin (Iasky and Lockwood, 2004). Further 

faulting and fault reactivation during the Early Cretaceous 

and the absence of regional or effective marine seals can 

have serious implications for seal integrity in the sandrich 

and faulted Upper Permian to Lower Cretaceous 

succession of the Bunbury Trough. However, not all of the 

folds have been dissected and other types of traps are also 

possible (Crostella and Backhouse, 2000). 

The northern and southern parts of the basin have 

similar stratigraphic histories (Fig. 4). For example, both 

parts contain thick intervals of coal measures within 

the Permian and Jurassic sections. However, viable 

objectives younger than Permian may be less likely in 

the Bunbury Trough (Crostella and Backhouse, 2000), 

as thermal maturity modelling suggests that only the 

Permian–Triassic section is within the oil window 

(Iasky, 1993). This is probably because of a lower rate 

of heat flow, which might be due the thick and relatively 

‘cool’ continental crust of the trough (Iasky, 1993). The 

Dandaragan Trough, which is the main depocentre and 

kitchen of the northern part of the basin with a comparable 

sedimentary fill to that of Bunbury Trough, has an 

average geothermal gradient of 2.5°C/100 m (Crostella,

GSWA 

Table 1. Petroleum wells up to 35 km south of State Acreage Release Area L12-14 and within the Bunbury Trough 

TD age Year Operator Status1 Status2 Gas show Oil show 

Total depth 

(m) 

Rig elevation 

(KB m, ASL) 

Name Class Latitude (S) Longitude(E) 

Chapman Hill 1 NFW 33°46'15.9" 115°18'54" 36.45 1 350 Jurassic 1992 Discovery Dry P&A Nil Nil 

Sabina River 1 NFW 33°39'53.3" 115°24'40.3" 13.24 4 309.3 Permian 1982 BP Dry P&A Poor Nil 

Whicher Range 1 NFW 33°50'07.9” 115°22'28.0" 153.16 4 653.08 Permian 1968 Union Gas P&A G Good Nil 

Whicher Range 2 EXT 33°50'26.3” 115°23'02.0" 159.19 4 330 Permian 1980 Mesa Gas P&A G Good Nil 

Whicher Range 3 EXT 33°52'15.0” 115°23'39.2" 137.58 4 496 Permian 1982 BP Gas P&A G Excellent Nil 

Whicher Range 4 EXT 33°50'22.3” 115°22'06.4" 140.12 4 575 Permian 1997 Pennzoil Gas SUSP G Excellent Nil 

Whicher Range 5 EXT 33°50'54.3” 115°21'36.8" 134.3 4 307 Permian 2003 Amity Gas P&A G Good – 

Wonnerup 1 NFW 33°50'54.3” 115°21'36.8" 24.38 4 727.45 Permian 1972 Union Dry P&A Fair Nil 

Amity Southern Amity Inc. 

BP BP Petroleum Development Australia Ltd 

Discovery Discovery Petroleum NL 

Mesa Mesa Australia Ltd 

Pennzoil Pennzoil Exploration Australia Inc. 

Union Union Oil Development Corp. 

P&A Plug and abandoned 

G Gas 

SUSP Suspended 

– No data 

NOTES: ASL Above sealevel 

TD Total depth 

NFW New field wildcat 

EXT Extension (as of December 2007) 

Wells in bold font are the most relevant and are discussed in detail. 

6 

1995). The corresponding rate for the Bunbury Trough 

is 1.9°C/100 m, despite the Early Cretaceous thermotectonic 

event, which resulted in widespread injection 

(and flows) of doleritic rocks in the Bunbury Trough 

(Iasky and Lockwood, 2004), including the Release Area 

(Commander, 1982; Iasky and Lockwood, 2004). Thus, 

a burial depth of more than 3 km is required for source 

rock maturity in the Bunbury Trough, as modelled for 

Wonnerup 1 and Sabina 1 (Iasky, 1993, figs. 38–41), 

although with increasing depth, reservoir quality is also 

likely to deteriorate (Crostella and Backhouse, 2000, 

fig. 30). It is also likely that contact metamorphism may 

have some local detrimental effect on reservoir quality 

(Sharif, 2007). Igneous intrusives are known from the 

Willespie Formation in Wonnerup 1, and the Lesueur 

Sandstone and the Yarragadee Formation in Whicher 

Range 2 (Crostella and Backhouse, 2000). 

Stratigraphy 

Geophysical studies suggest that the northern part of the 

Bunbury Trough is likely to contain a Permian section 

that is more than 6 km thick (Crostella and Backhouse, 

2000, fig. 12). The section consists of the Stockton Group, 

directly overlain with the coal-bearing Sue Group (Fig. 4). 

The latter group includes thermally mature source rocks, 

and potential sandstone reservoirs. The Permian section 

has an overburden up to 4 km thick, mainly consisting of 

Triassic and Jurassic continental clastic facies. These are 

likely to be overlain with up to about 400 m of the Lower 

Cretaceous Leederville Formation in the central-northern 

and eastern parts of the Release Area. A veneer of late 

Cenozoic sediments not more than 30 m thick may cover 

the Swan Coastal Plain, mainly along the Whicher Scarp. 

The Upper Jurassic Yarragadee Formation and the Lower 

Cretaceous Bunbury Basalt and the Leederville Formation 

may be exposed along, and to the east of, the axis of the 

Capel Anticline, in the central to northwestern parts of the 

Release Area (Commander, 1982). 

Since the southern part of the Perth Basin was probably 

emergent during most of the Permian and Mesozoic 

(Norvick, 2004), regional or effective marine seal and 

source rocks — such as the Lower Triassic Kockatea 

Shale or the Middle Jurassic Cadda Formation — are 

unlikely to be present in the Bunbury Trough (Fig. 4). 

Thus, blanketing of the Permian synrift reservoirs by a 

thick post-rift and shale-rich Lower Triassic succession 

did not extend to the south. For the same reason, good 

quality shallow marine reservoirs may be missing from 

the Permian section in the south (Crostella and Backhouse, 

2000, fig. 26). 

Permian 

Deposition in the southern Perth Basin began in the 

Early Permian with the Stockton Group, consisting of 

fluviolacustrine argillaceous sandstone and siltstone of the 

Mosswood Formation and a basal diamictite unit (Fig. 4). 

This formation grades up to the Sue Group, consisting

of poorly sorted feldspathic sandstone with subordinate 

intervals of conglomerate, siltstone, shale, and sporadic 

thin or lenticular sub-bituminous to bituminous coal. The 

Sue Group consists of two intervals of coal measures 

and three sandstone-rich units in the Vasse Shelf area 

(Crostella and Backhouse, 2000). However, none of the 

wells in the Bunbury Trough has completely penetrated 

this succession. 

Wonnerup 1 penetrated 623 m of the Willespie Formation 

at the top of the Sue Group (depth of 4104–4727 m, 

Crostella and Backhouse, 2000, appendix 3), including 

two doleritic sills 2 m and 13 m thick. Analyses of wireline 

logs show that porosity ranges between 29% and 43% and 

permeability between 32 mD and 650 mD, whereas water 

saturation varies between 38% and 74% in this formation 

(Crostella and Backhouse, 2000, table 6). These values 

are well above those normally given for a tight sand 

reservoir (0.1 mD; WA:ERA, 2012). Sabina River 1 also 

penetrated 469 m of the Willespie Formation, showing 

porosity of 9.5% to 16%. This well may have failed to test 

a valid trap, and it is likely that subseismic faulting has 

compromised trap integrity in Wonnerup 1 (Crostella and 

Backhouse, 2000). 

Triassic 

The Triassic section consists of the fluvial Sabina 

Sandstone and the Lesueur Sandstone (Fig. 4). The 

Sabina Sandstone consists of moderately sorted, poorly 

consolidated and micaceous green-grey sandstone with 

disconformable contact with the Willespie Formation, 

and grading up to the Lesueur Sandstone. The Sabina 

Sandstone is 226 m thick in Sabina River 1 and 461 m 

thick in Wonnerup 1. This unit may become over 500 m 

thick in the northeastern part of the Bunbury Trough 

(Crostella and Backhouse, 2000, fig. 13), containing 

thicker or more frequent layers of shale, claystone, and 

siltstone with increasing distance from the Vasse Shelf. 

The Lesueur Sandstone is likely to be more than 1700 m in 

the Release Area (Crostella and Backhouse, 2000, fig. 14). 

It is divided into two informal members, the Wonnerup 

and the Yalgorup (formerly the Myalup), in ascending 

order. The Wonnerup Member is 1004 m thick at its type 

section in Wonnerup 1, consisting of homogenous, poorly 

sorted, coarse to very coarse-gained and feldspathic, lightgrey 

sandstone. The Yalgorup Member is 1158 m thick in 

Wonnerup 1, consisting of dark-grey sandstone, probably 

grading up to the Eneabba Formation rather than the 

Cattamarra Coal Measures. The boundary between the two 

members of the Lesueur Sandstone is a regional seismic 

marker, although they were both probably deposited as 

channel deposits in fluviatile environments. 

Jurassic 

The Jurassic section consists of predominantly continental 

deposits in the Perth Basin, except for the relatively 

thin marine Cadda Formation, which is restricted to the 

northern part of the basin (Fig. 4). The Lower Jurassic 


7 

Cattamarra Coal Measures may be over 1200 m thick in 

the Release Area (Crostella and Backhouse, 2000, fig. 15), 

given that it is 1271 m thick in Wonnerup 1 and thins out 

to 850 m in Sabina River 1 (Crostella and Backhouse, 

2000). Thickness of the coal measures may increase from 

429 m in bore 1 of the Boyanup Line near the coast to 

as much as 635 m in bore 1 of the Picton Line, east of 

Bunbury (Fig. 3). The upper contact with the Yarragadee 

Formation appears to generally deepen from the west 

to the east across the Release Area (Smith, 1984). As 

noted above, the distinction between the Cattamarra Coal 

Measures and the Eneabba Formation is not clear in the 

Bunbury Trough. 

The Cattamarra Coal Measures contain coarse-grained 

quartz sandstone, interbedded with dark and carbonaceous 

fine-grained clastic rocks and coal seams. The coal seams 

are good seismic markers, although they cannot be 

correlated over a large distance because of the lenticular 

nature of the seams (Crostella and Backhouse, 2000). The 

sandstone units are interpreted to have been deposited in 

distributory channels within a fluvial braided and paludal 

complex. Coaly intervals indicate deposition in a marshy 

embayment, showing a conformable contact with the 

overlying Middle–Upper Yarragadee Formation. 

The Yarragadee Formation is about 800 m thick in the 

Sabina River 1 and Wonnerup 1, becoming up to about 

850 m thick in Picton Line bore number 4 (PL 4) near 

the Darling Fault (Fig. 3; Wharton, 1980). This unit has a 

comparable thickness of 700 m to 800 m in bores BL 2, 

BL 3, and BL 4 along the Boyanup Line, although its 

thickness is reduced to about 500 m near the coast in 

bore BL 1 (Smith, 1984). The formation consists of fine 

to coarse-grained, poorly sorted feldspathic sandstone, 

showing a conformable contact with the overlying 

Parmelia Group. Thin beds of shale, siltstone and coal may 

be also present with the formation, which is predominantly 

of fluvial origin, with minor overbank or swamp deposits. 

Along the Quindalup Line (Fig. 3), the Mesozoic section is 

dissected by the Darradup Fault between bores QL 5 and 

QL 6 (Wharton, 1981, fig. 3). The top of the Cattamarra 

Coal Measures deepens eastward between QL 4 and QL 9, 

and the overlying Yarragadee Formation thickens in the 

same direction, becoming over 1200 m near the Darling 

Fault. These trends are in general agreement with those of 

seismic interpretation (Iasky, 1993), confirming that the 

thickness of the Mesozoic section increases from west to 

east across the Release Area. 

Cretaceous 

The Cretaceous sedimentary section is divided into a 

number of units within the Bunbury Trough (Crostella 

and Backhouse, 2000). The Bunbury Basalt and the 

Leederville Formation are most widely intersected in 

hydrogeological bores, covered by no more than a few 

tens of metres of Cenozoic sediments, mainly near the 

coast and the Whicher Range. The Leederville Formation 

and the basalt may crop out in the northwestern part of the 

area (Commander, 1982).

GSWA 

Cretaceous 

Jurassic 

Triassic 

Permian 

AGE 

Cenozoic 

65 

145 

200 

252 

Lower M U L Middle Upper Lower Middle Upper Lower 

Upper 

259 

Carboniferous 

Devonian 

Silurian 

OrdovicianPrecambrian 

S N 

STRATIGRAPHY 

Source 

Coolyena Group 

Warnbro 

Group 

Bunbury 

Basalt 

Sue 

Group 

Stockton 

Group 

Sabina 

Sandstone 

Poison Hill 

Greensand 

Leederville Fm 

South Perth Shale 

Willespie Fm. 

Redgate C.M. 

Ashbrook Ss. 

Rosabrook 

Coal Measures 

Woodynook Ss. 

Mosswood Fm. 

Parmelia Group 

Yarragadee 

Formation 

‘Cullens Diamictite’ 

laterite 

Kings Park Shale 

Gingin Chalk 

Molecap Greensand 

Osborne Formation 

Dandaragan Ss. 

NOT PENETRATED 

Lancelin 

Formation 

Cattamarra 

Coal 

Measures 

Lesueur 


Eneabba Formation 

Beekeeper 

Fm. 

basement 

Quaternary units 

Gage Sst. 

Cadda Formation 

Woodada Fm. 

Kockatea Shale 

Dongara Ss. 

Otorowiri Fm. 

Irwin River Carynginia Fm. 

Coal Measures 

High Cliff Sandstone 

Holmwood Shale 

Nangetty Formation 

Tumblagooda 


8 

Gage Roads 1 

Gingin 1 Warro 1, Bootine 1, 

Ocean Hill 1, 

Gingin West 1 

Mt Horner/North Yardanogo 1 

Walyering 

Houtman 1/Ocean Hill 1/ 

Erregulla 1/Walyering 1 

Erregulla 1 

Agonis 

Dongara/Mt Horner 

Dongara* Whicher Range 

Evandra 

Woodada/ 

Hovea Beharra Springs 

Yardarino Arrowsmith 1 

Dongara 

† 

Cliff Head 

* also Xyris, Tarantula, Apium, 

Mondarra (now depleted), 

Corybas 

† 

also Beharra Springs N, 

Jingemia, Eremia 

AJM777a 18.06.12 

Dominant lithology 


Carbonate– 

shale, marl 

Secondary lithology 


Shale 

Basalt 

Shale 

Mixed siliciclastic 

and coal 

Carbonate 

Basement Diamictite 

Wagina 

Fm. 

Gas show 

Oil show 

Oil and gas 

show 

Oilfield 

Gasfield 

Reservoir 

Seal 

Oil and gas field 

Gas and condensate 

field 

Fm. Formation 

Ss. Sandstone 

C.M. Coal Measures 

Hydrocarbon 

fields and 

significant shows 

Figure 4. Comparative stratigraphy of the northern and southern parts of the onshore Perth Basin 

Unconformity 

Disconformity

Conclusions 

A Permian section over 6 km thick is likely to be present 

in the Release Area. The section should contain mature 

source rocks, as its overburden is more than 3 km thick. 

Some intervals of the Willespie Formation may have a 

porosity and permeability greater than 0.1 mD, which is 

the limit of a tight sandstone reservoir. The presence of gas 

may also inhibit silicification of the sandstone. 

Structural trends of the Wonnerup prospect and the 

Whicher Range Gasfield appear to extend northward into 

the area, where the Mesozoic section is gently folded near 

the coast. North–south trending normal faults may also 

dissect the pre-Cretaceous succession in the area. 

Early Cretaceous igneous intrusives have been 

encountered in many water bores within the area. 

Interpretation of aeromagnetic data also suggests that the 

intrusives are widely distributed in the northern part of 

the Bunbury Trough. Significant intervals of intrusives 

have also been encountered in the Willespie Formation 

(Wonnerup 1), Lesueur Sandstone, and Yarragadee 

Formation (Whicher Range 2). It is not known if the 

associated heat pulse had any effect on maturity of the 

post-Permian to pre-Cretaceous organic-rich intervals, 

such as the Jurassic coal measures. 

References 

Commander, DP 1982, The Bunbury shallow drilling groundwater 

investigation: Geological Survey of Western Australia, Report 12, 

p. 32–52. 

Crostella, A 1995, An evaluation of the hydrocarbon potential of the 

onshore northern Perth Basin, Western Australia: Geological Survey 

of Western Australia, Report 43, 67p. 

Crostella, A and Backhouse, J 2000, Geology and petroleum exploration 

of the central and southern Perth Basin, Western Australia: Geological 

Survey of Western Australia, Report 57, 85p. 

Dentith, MC, Long, A, Scott, J, Harris, LB and Wilde, SA 1994, The 

influence of basement on faulting within the Perth Basin, Western 

Australia, in The Sedimentary Basins of Western Australia edited 

by PG Purcell and RR Purcell: Petroleum Exploration Society of 

Australia; Western Australian Basins Symposium, Perth, WA, 1994, 

Proceedings, p. 791–799. 

Ferdinando, D and Dedman, R 2003, Review of 2002 exploration, 

production and development activities in Western Australia: 

Department of Industry and Resources, Petroleum in Western 

Australia, April 2003, p. 6–24. 

Freeman, MJ and Donaldson, MJ 2006, Geology of the southern Perth 

Basin and Margaret River wine district, southwestern Western 

Australia: Geological Survey of Western Australia – a field guide, 

Record 2006/20, 38p. 

Geological Survey of Western Australia (GSWA) 2011, Summary 

of petroleum prospectivity, Western Australia 2011: Amadeus, 

Bonaparte, Bight, Browse, Canning, Officer, Perth, Southern 

Carnarvon, and Northern Carnarvon Basins: Geological Survey of 

Western Australia, Perth, Western Australia, 42p. 

Harris, LB 1994, Structural and tectonic synthesis of the Perth Basin, 

Western Australia: Journal of Petroleum Geology, v. 17, p. 129–156. 


9 

Hocking, RM 1994, Subdivisions of Western Australian Neoproterozoic 

and Phanerozoic sedimentary basins: Geological Survey of Western 

Australia, Record 1994/4, 84p. 

Iasky, RP 1993, A structural study of the southern Perth Basin, Western 

Australia: Geological Survey of Western Australia, Report 31, 56p. 

Iasky, RP and Lockwood, AM 2004, Gravity and magnetic interpretation 

of the southern Perth Basin, Western Australia: Geological Survey of 

Western Australia, Record 2004/8, 32p. 

Iasky, RP, Young, RA and Middleton, MF 1991, Structural study of 

the southern Perth Basin by geophysical methods: Exploration 

Geophysics, v. 22, p. 199–206. 

Luck, GR 1990, Hydrocarbon potential of the Perth Basin: Geological 

Survey of Western Australia, Record 1995/5, 26p. 

Norvick, MS 2004, Tectonic and stratigraphic history of the Perth Basin: 

Geoscience Australia, Record 2004/16, 30p. 

Sharif, A 2007, Tight gas resources in Western Australia: Department of 

Industry and Resources, Petroleum in Western Australia, September 

2007, p. 28–31. 

Smith, RA 1984, Geology and hydrogeology of the Boyanup bore line, 

Perth Basin, in Professional Papers for 1982: Geological Survey of 

Western Australia, Report 12, p.72–81. 

Western Australian Energy Research Alliance (WA:ERA) 2012, Whicher 

Range tight gas sands study: Geological Survey of Western Australia, 

Report 112, 405p. 

Wharton, PH 1980, The geology and hydrogeology of the Picton 

borehole line, in Annual Report of the Year 1979: Geological Survey 

of Western Australia, Perth, Western Australia, p. 14–19. 

Wharton, PH 1981, The geology and hydrogeology of the Quindalup 

borehole line, in Annual Report of the Year 1980: Geological Survey 

of Western Australia, Perth, Western Australia, p. 27–35. 

Wilde, SA and Nelson, DR 2001, Geology of the western Yilgarn Craton 

and Leeuwin Complex, Western Australia – a field guide: Geological 

Survey of Western Australia, Record 2001/15, 41p.

Area Summary L12-14 - Department of Mines and Petroleum

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