COMMONWEALTH OF AUSTRALIA

STATE OF

1:250,000 GEOLOGICAL SERIES-EXPLANATORY NOTES

Chinchilla, Qld

SHEET SG/56-9 INTERNATIONAL INDEX COMPILED BY R. F. REISER

Published by the Bureau of Mineral Resources, Geology and Geophysics, and issued under the authority of the Honourable R. W. C. Swartz, M.B.E., E.D., M.P., Minister for National Development 1971. COMMONWEALTH OF AUSTRALIA

DEPARTMENT OF NATIONAL DEVELOPMENT MINISTEll: THE HON. R. W. C. SWAIITZ, M.B.B., E.O., M.P. SECUTUY: L. F. BOTT, D.S.C.

BUREAU OF MINERAL RESOURCES, GEOLOGY AND GEOPHYSICS D1ucroa: N. H. FISH!!&. GEOLOGICAL BllANCH; ASSISTANT DlllECTOR: J. N. CASEY.

STATE OF QUEENSLAND DEPARTMENT OF MINES MINISTl!a: THE HoN. R . L. A. CAKII, M.L.A. UHDE& SEClll!TARY: E. K . HEALEY.

GEOLOGICAL SURVEY OF QUEENSLAND CHIEF GEOLOGIST: J. T . WOODS.

Printed in Australia by the Tasmanian Government Printer, Hobart Explanatory Notes on the Chinchilla Geological Sheet

Compiled by R. F. Reiser

(Geological Survey of Queensland.)

The main centres of population are Chinchilla (population 3300), Miles (population 1500) , and . The southern half of the Sheet area is well served by sealed roads. Chinchilla and Miles lie on the W arrego Highway linking and Roma; from Dalby, a major town to the south of the Sheet area, the Jandowae-Dalby road gives access to the southeast, and the Condamine Highway to the far south and southwest; the gives access to the western edge of the Sheet area. There are few sealed roads in the northern half, but formed roads are generally closely spaced, giving ready access to most areas. Chinchilla, Miles, and Condamine all have regular air services. The Western Railway serves Chinchilla and Miles and a branch line from Dalby runs to Jandowae; the Barakula Tramway runs from Chinchilla to the sawmills of the Barakula area, and a branch line from Miles runs to . The area was mapped during 1967 as part of a regional mapping pro­ gramme of the Surat Basin (Exon, Reiser, Jensen, Burger, & Thomas, 1968) conducted jointly by the Bureau of Mineral Resources and the Geological Survey of Queensland. Rivereau (1966) prepared a photogeo­ logical map of the area before field work began. The heavy clay soil of the alluvial plains of the Condamine River system once supported dense brigalow scrub; this has now been cleared and cultivated for cash and feed crops. The sandy soils developed on the sand­ stone, granite, and metamorphic terrain of the north and west are covered by open forest suitable for cattle grazing. Forest reserves in this area supply several sawmills. In the southwest, where relief is less rugged, sheep are raised. Vine scrub dominated the vegetation of the basalt-covered areas of the southeast; where relief is not too extreme, this scrub has been cleared and the area now supports an intensive dairying industry.

Air photographs at 1:85,000 nominal scale flown by Adastra Airways in 1963 cover the area. A topographic map at a scale of 1:250,000 is currently being produced by the Royal Australian Survey Corps.

3 PREVIOUS INVESTIGATIONS Geological Jack & Maitland (1894) covered the area as part of a geological reconnaissance of inland Queensland. Jack (1896) suggested a Triassic­ Jurassic age for the basalts of the eastern part of the Sheet area, and recorded Palaeozoic rocks in the far north at Cadarga (grid ref. 396756). Coal occurrences at Jimbour ( 424653) and Chinchilla were investigated by Cameron (1910) and Marks (1910) respectively. Walkom (1918) showed the distribution in Queensland of the Walloon Series, which included most of the Jurassic of the Chinchilla Sheet area. Jensen's (1926a) reconnaissance included part of the Sheet area north and west of Chinchilla. He mapped the Upper Triassic Bundamba Series and the Jurassic Walloon Series. Ball (1931) identified fossil plants from Guluguba (296738), and commented on deep weathering effects in this area. Coal at Warra (391657) was examined by Cribb (1944), who also noted fossil vertebrate bones in sand and gravel. These deposits, together with those at Chinchilla and Brigalow, were grouped by Bryan & Jones (1946) with the Pleistocene Diprotodon beds; Woods (1956, 1960) has since shown that these are more probably of Pliocene age. Sturmfels (1954) mapped the Miles-Wandoan area. Isbell (1962) worked on the soils of the brigalow lands of Eastern Australia, including the Chinchilla Sheet area. The Sheet area was mapped at a regional scale by McTaggart (1963a) ; the findings of Exon et al. (1968) agree broadly with those of McTaggart. Webb, Stevens, & McDougall (1967) determined isotopically the age of contiguous Tertiary basalts to the south and east of the Sheet area as early Miocene. Casey, Gray, & Reiser (1968) briefly reviewed the Lower Mesozoic stratigraphy. Geophysical Geophysical surveys by companies and the Bureau of Mineral Resources are listed in Table 1; the surveys are concentrated in the sedimentary areas of the west and south. Bouger anomaly contours shown on the geological map are from a survey by the Bureau of Mineral Resources (Lonsdale, 1965). Aeromagnetic work for Union Oil Development Corporation, which defined the eastern flanks of the Mimosa Syncline, was summarised and interpreted by Aero Service Corporation (1963). Seismic surveys for Union Oil Development Corporation (e.g. Kahanoff, 1962b; United, 1964, 1966) and for Phillips Petroleum Company (Fjelstul & Beck, 1963) showed detailed structure, particularly the faulting on the east flank of the Mimosa Syncline. Seismic surveys in the centre of the Sheet area were completed for Condamine Oil Ltd (McQueen & Warner, 1962; Warner & Klaudt, 1963), and re-interpreted by Companie Generale de Geophysique (1963).

4 TABLE 1.-GEOPHYSICAL SURVEYS IN THE CHINCHILLA AREA

Short Title Survey Organisation Reference

Central and South- Gravity along seismic Bureau of Mineral Darby, 1965 em Queensland lines; far south of Resources Sheet area Southern Queens- Regional gravity Bureau of Mineral Lonsdale, 1965 land Resources NE New South Regional gravity Bureau of Mineral Langron & van Wales, SE Resources Son, 1967 Queensland Surat-Bowen Basin Aeromagnetic Union Oil Develop­ Union, 1960 ment Corp. Moree-Miles Aeromagnetic Union Oil Develop­ Kahanoff, 1962a ment Corp. Moree-Miles Aeromagnetic Union Oil Develop­ Aero Service Corp. ment Corp. 1963 Miles-Dulacca Reconnaissance Union Oil Develop­ Kahanoff, 1962b seismic ment Corp. Yuleba Reconnaissance Union Oil Develop­ Kahanoff, 1963 seismic ment Corp. Chinchilla area Detailed seismic; Condamine Oil Ltd McQueen & small area in Warner, 1962 centre of Sheet Barakula Detailed refraction Burmah Oil Co. Warner & Klaudt, seismic; small area 1963 in centre of Sheet Chinchilla area Reinterpretation of Condamine Oil Ltd CGG, 1963 earlier seismic in central area Western ATP 71P Reconnaissance and Phillips Petroleum Fjelstul & Beck, detailed seismic; Co. 1963 southeast Moonie River Detailed seismic; Union Oil Develop- United, 1964 west ment Corp. Condamine Detailed seismic; Union Oil Develop- United, 1966 southwest ment Corp.

Exploratory drilling for petroleum The earliest wells in the area were Murilla Oil Company 1 (Boyanda) near Miles and Condamine Oil Ltd 1 (Speculation): both reported minor shows. In the early 1960's, the Union Oil Development Corporation began prospecting for oil in' an area which included the western part of the Sheet area. Promising results in wells in adjacent areas (gas shows in UKA Buranga 1 and oil in UKA Cabawin 1 and UKA Conloi 1) led to the drilling of fourteen wells in the Sheet area, sited from geophysical evidence on the culmination of small fault-controlled anticlines on the eastern flank of the Trough; they were aimed at the Precipice Sandstone in structural traps or pinchouts in anticlinal flanks. Results are summarised in Table 2.

PHYSIOGRAPHY The physiography of the Sheet area is summarised in Fig. 1. Drainage is to the Condamine, Burnett, and Dawson Rivers. The Condamine River is part of the Darling River System; the Burnett and Dawson Rivers flow

5 into the Pacific. The main stream divide constitutes part of the so-called Great Dividing Range; the name is difficult to justify in the mainly flat western part.

0 10 20 30 KI LOMETRES G 54/A/3 0 10 20 MILES

Boso/I-copped mesas Vnduloling sandy § , l[&J country Rood Rounded hills Vnduloling clayey ~ ~- country --- Roilwoy Sandstone m,so$ Sand ond soil / [TIIJ D plains / Oivide Figure 1. Physiography

The most rugged country in the Sheet area is in the east and north­ east, and relief decreases to the west and south. In the southeast, there are basalt-capped mesas separated by valleys of rich clay soil. The basalts were flows filling valleys developed in the soft Marburg sediments; the sediments have since been extensively eroded to give the present reversed relief; in a few areas, topographic reversal is not complete, and sandstone mesas remain. In the northeast, the granite and metamorphic rocks have weathered to a terrain of rounded hills with V-shaped valleys. Elevation falls to the north, following the Boyne River, from 1500 feet to 700 feet. The topography of the remainder of the Sheet area has resulted from more or less intensive erosion of once extensive pediplain developed during

6 TABLE 2.-EXPLORATORY DRILLING IN THE CHINCHILLA AREA

Total Depth Name of Well Year Drilled Grid Reference (Feet) Hydrocarbon Shows Reference

Murilla Oil Co. 1 (Boyanda) 1935-1953 304691 ?4721 Gas at some levels Condamine Oil Ltd (Specula­ 1948-1963 363713 2885 Some oil and gas shows Mott & Associates, 1963 tion) Union-Kem-AOG (UKA) 1962 300770 10242 Fluorescence in Precipice; UKA, 1964a Burunga 1• (Mundubbera Sheet) traces gas and oil in Kianga tuff 4179'. Back Creek gas shows from 7480' to 8015' UKA Mackie 1• 1963 330656 3969 Gassy fresh water from Pre- Union, 1963 cipice (3754'-3770') Phillips-Sunray-Queensland 1963 378640 3438 No shows Kyranis, 1963 American Kogan 1• (Dalby Sheet) Condamine Oil Ltd Canaan 1• 1964 364715 1635 No shows McTaggart, 1964 UKA Picurda 1• 1964 325656 3995 No shows Union, 1964a -..J UKA Conloi 1• 1964 289718 6005 Production test in Evergreen: Union, 1964b (Roma Sheet) 4313'-4321', 400 bbl UKA Gurulmundi 1• 1964 296718 4784 No shows Union, 1964c UKA Tin Hut 1 1964 3l0723 3467 No shows UKA Weringa 1• 1964 295758 4977 No shows Union, 196S UKA 1 1965 319681 3925 No shows UKA Dogwood 1 1965 310687 4138 No shows Phillips-Sunray Y arrala 1• 1965 416636 2955 No shows Meyers, 1965 (Dalby Sheet) UKA Auburn 1 1966 297703 6114 No shows UKA Binky 1 1966 319728 1978 No shows UKA Bullock Ck 1966 327722 1650 No shows UKA Bulwer 1 1966 318677 3917 No shows UKA Burunga South 1966 304752 8524 No shows UKA Paddy Ck 1 1966 300695 S2S9 No shows UKA Pelham 1 1966 323723 2051 No shows UKA Range 1 1966 296722 4440 No shows

• Subsidised by Commonwealth Government; completion reports of subsidised wells are available for study at the Bureau of Mineral Resources and Geological Survey of Queensland. NOTE.-Summary reports involving some of Union's subsidised wells are also available (Mack, 1964, 1965). Unsubsidised wells are summarised in GSQ, 1960-64, and Queensland Mines Department, 196S, 1966. TABLE 3.-PRE-JURASSIC STRATIGRAPHY OF THE CHINCHILLA SHEET Name Age (Map Lithology Thickness Relationships Fossils• Depositional Major Published Symbol) (Feet) Environment Reference

TRIASSIC aematis Grey to grey-green Up to 1300 Unconformable on (Actritarchs, River and lake Sand- clayey sublabile TRlr spores and deposition, con- stone sandstone; con- pollen grains) temporaneous (TR) glomerate, shale, vulcanism, siltstone some marine episodes

LOWER Rewan Multicoloured vol- Up to 2000 Unconformable on (Spores and Redbed sequence Isbell (19 55); full TRIASSIC Form- canic and lithic Pb in south, and pollen grains) deposited in discussion in ation sandstone, some Puw in north continuously Mollan et al, (TRlr) clayey; conglom- subsiding (1969) crate. siltstone, shallow basin shale from streams I and in lakes 00 @ UPPER VJ Black- Tuffaceous siltstone Up to 2500 Conformable on Pb; (Plants; spores Lakes and PERMIAN water and sandstone, penetrated by wells and pollen swamps; some ~ Group calcareous in part; in northern pan grains) vulcanism < (Puw) abundant tuff to- of Taroom i:Q wards base; car- Trough; cannot bonaceous shale, be differentiated coal from Pb by seismic I data in south and 0 hence not separ- i:Q ated on cross- section

LoWER Back Tuffaccous shale, Up to 5100 Unconformable on (Brachiopods, Varying marine Mollan et al, PERMIAN Creek siltstone, sandstone, P-C pelecypods, and freshwater (1964) . ..I Group conglomerate, gastropods, with contemp- (Pb) minor coal crinoids, corals, oraneous bryozoans, vulcanism spores, pollen, plants) Auburn Hornblende-biotite Part of Auburn Denmead (1938) Granite granite grading Complex; intrudes (Pga) to granodiorite; Lower Permian acid to basic dykes Camboon Andesite to north PERMIAN Granite of Hornblende-biotite Part of Yarraman Unknown Hill & Denme.ad, Yarra- granite grading to Complex; genetic eds (1960, man granodiorite; acid relationship with p. 251) Block to basic dykes contiguous meta­ (Pgy) morphic rocks un­ known, although contact is generally gradational

PERMIAN· ~ (P-C) (in- Diverse rock types Subsurface only; TO CARB- ~ eludes older than Back relationships with ONIFER· ~ Camboon Creek Group in outcropping Car­ ous Cll Andesite oil wells: welded boniferous rocks l:Q< of Mun- tuff, andesite, unknown dubbera dacite, and basalt IO_ ....u Sheet flows, agglomerate, 2 area) sandstone 0 CARBON· (C) Basic to acid pyro- At least Lower contact not Solitary corals, Deep. to shallow IFEROUS ~ elastics and lavas; 1000 seen beyozoans, marine with tuft', sandstone, bracbiopods contemporan­ p..~ siltstone and shale, eous vulcanism; oolitic sandstone, locally terres­ calcarenite lenses trial and recrystallised limestone, massive conglomerate

PALAEOZOIC Meta- Schist, gneiss, foli- Generally ·grad­ morphic ated granodiorite; ational contact rocks of minor phyllite; with Pgy Yarra- acid to basic man dykes; grade of Block metamorphism (Pzm) increases to the north

• Names in brackets indicate fossil types found only outside Sheet area. the formation of a deep weathering profile on the Mesozoic sediments. Sandstone mesas separated by wide shallow valleys have developed where the crust of the deep weathering profile has remained as a capping on ridges. More vigorous erosion has reduced the more resistant material to a few small mesas in a landscape of undulating sandy country. Undula­ ting clayey country has formed where extensive stripping of deep weather­ ing mantle has exposed relatively unaltered siltstone, mudstone, and labile sandstone. Dominating the central and southern parts of the Sheet area are the sand and soil plains of the Condamine River. The Durong Plain, a slightly elevated northeastern extension of this alluvial plain, probably represents an old course of the Condamine River.

STRATIGRAPHY The stratigraphy is summarised in Tables 3, 4, and 5. The major published references to stratigraphic names are included in the tables. Pre-Jurassic geology is illustrated in Fig. 2.

Pre-Jurassic Rocks (Table 3) Palaeozoic granite and metamorphic rocks of the Yarraman Block represent the southernmost extension of the South Coastal Structural High (Hill, in Hill & Denmead, eds, 1960, p. 3), which forms the eastern boundary of the Middle Devonian to Lower Permian Yarrol Basin. Con­ tacts between the granite and metamorphic rocks appear gradational; the genetic relationship is unknown although the granite is thought to be younger (Permian according to Webb & McDougall, 1968) . Rhyolite dykes cut the granite of the Yarraman Block and are presumably late stage differentiates. The Auburn Granite is part of the Auburn Granitic Complex (Hill & Denmead, op. cit., p. 3), which bounds the Yarrol Basin on the west. The intervening outcropping Carboniferous sediments are part of the Yarrol Basin sequence, and the sparse information from exploratory drilling suggests that the undivided Carboniferous-Permian rocks (Map symbol P-C), which constitute basement over much of the Sheet area, are also part of that sequence. Basic dykes are common in the Auburn Granite, and have also intruded the Carboniferous sediments and the granite of the Yarraman Block.

The unconformably overlying sequence of marine and freshwater sediments of the Permian Back Creek and Blackwater Groups and the Triassic Rewan Formation and Clematis Sandstone is part of a southward extension of the Bowen Basin, a Permian-Triassic basin which crops out extensively to the north; the sediments are preserved in this area only in the Taroom Trough underlying Surat Basin sediments. The sequence is broadly conformable, although there is evidence of breaks in deposition at the bases of the Rewan Formation and Clematis Sandstone.

10 TABLE 4.-SURAT BASIN SEDIMENTS IN THE CHINCHILLA AREA

Age Name Lithology Thickness Environment of Major Published (Map Symbol) (Feet) Fossilst Deposition Reference

§ LoWER ~ Coreena Siltstone, mudstone, 300-500 (Lower Albian belem- Shallow marine, Vine et al., CRETACEOUS 5 Member* fine sandstone, nites and pelecypods; strand-line (1967) '-" Klc glauconitic in part foraminifera; spores ~ and pollen of Kld-K2a "' zones) i Doncaster Mudstone, siltstone, 300-400 (Aptian shelly fossils; Deltaic and near-shore Vine & Day .a Member* fine sandstone, spores and pollen of (1965) -:; Kld glauconitic in part Klb-c zones; plants) Vine et al., ~ (1967) Bungil Form­ Siltstone; clayey quartz­ 250 (Neocomian-Aptian Lake and stream in Exon & Vine ation* ose to lithic sandstone, pelecypods and bele­ lower part, brackish (1969) Kly glauconitic in part; mnites; spores, pollen, to marine in upper mudstone and microplankton of Kla-c zones). Plants Mooga Clayey, fine quartzose 250 Spores and pollen of Stream and lake Reeves (1947) Sandstone to lithic sandstone, Kla zone; plants Klm siltstone

JUitASSIC TO Kumbarilla Clayey labile to quartz- 2000± Spores and pollen of Stream, delta and lake; Exon & Vine LoWER Beds* ose sandstone; silt- J5-6, Kla-c zones; minor marine near (1969) CRETACEOUS J-Kk stone, mudstone; plants top minor claystone, coal and polymictic con­ glomerate

Ul'PER JURASSIC Orallo Form­ Clayey lithlc sandstone, 500-800 Plants; microfossils of Stream and lake, Day (1964) ation* siltstone and minor ~ J6 zone explosive volcanic Juo mudstone and clay- material and lithic stone; minor benton- , detritus from volcanic ite, polymictic con- rocks glomerate Gubbera­ Cross-bedded quartzose Up to 200 Spores and pollen of Fast-flowing streams Reeves (1947) munda to sublabile sandstone; J5-6 zones; plants Sandstone conglomerate, silt- stone, fossil wood

MIDDLE TO lnjune Creek'' Calcareous lithic sand­ 1500-2000 (Plants); spores and Meandering streams, Exon (1966); U PPER JURASSIC Group Ji stone, siltstone, and pollen of J4-6 zones back swamps and Power & Devine (includes mudstone; bands of lakes, favouring (1968) Springbok coal common through­ formation of coal Sandstone out; abundant ande­ and sitic volcanic detritus Birkhead Formation) Hutton Sand­ Quartzose to sublabile 800± Spores and pollen of N and NE-flowing Reeves (1947); stone* sandstone, some J2-4 zones streams eroding gran­ Mollan et al. nh clayey, some pebbly, ites and sediments; (in prep) thinly bedded siltstone channel sands, with point-bar and over­ bank deposits l..oWER JURASSIC Evergreen Mudstone, siltstone, Generally Plant fragments; Lake and low-energy Evergreen Shales Formation minor sandstone 500-600 spores, pollen, and stream Whitehouse (basinal thinner acritarchs of J1 and (1952) Mollan et facies) where 2 zones al. (in prep.) ne overlies basement (e.g. 284 in UKA Bull­ ock Ck 1) Siltstone and fine 130-200 Plant fragments, some Sluggish streams, with feldspathic to sub- leaf impressions; widespread back labile micaceous sand- spores and pollen of swamps stone; well-bedded, J2 zone with cross-laminations and ripple marks Fine lithic sandstone, 30-70 Acritarchs: spores and Marine or brackish · siltstone, and mud­ pollen of J2 zone quiet standing water stone; concretionary ironstone, part· oolitic

Thick-bedded and 400-1000 Spores and pollen of Initially fast-flowing cross-bedded arkose; J1 zone streams eroding base­ coarse to pebbly felds- ment highs; subse­ pathic sandstone, quently meandering calcareous in part; streams some well-bedded siltstone and mudstone Marburg* Well-bedded micaceous 1000-1200 Spores and pollen of Generally fast-flowing Staines (1964) Sandstone feldspathic to sublabile Jl and J2 zones; streams eroding fairly Jlm fine to medium sand­ plants youthful topography stone, with some on Y arraman Block clayey qmrtzose and pebbly sandstone; minor siltstone, and mudstone; some low angled cross­ bedding and ripple marks; minor pelletal ironstone

Precipice Cross-bedded, pebbly, Up to 550 Spores and pollen of Initially fast-flowing Whitehouse Sandstone quartzose clayey sand­ Jl zone streams, with energy (1952, 1954); JJp stone becoming finer gradually decreasing Mollan et al. towards the top; finely towards top (in prep.) interbedded micaceous siltstone becoming more common to­ wards the top

* Area of deeply weathered sediments shown on maps by stipple over normal colour and symbol. t Names in brackets indicate fossil types found only outside Sheet area; zones erected by Evans (1966). F.p. 11. Surat Basin Sequence (Table 4) The Surat Basin sequence is conformable throughout; the sequence developed in the Mimosa Syncline* is typical of the Surat Basin proper. On the stable shelf to the east, which includes most of the Chinchilla Sheet area, most of the Lower Jurassic part of the sequence was deposited from fast-flowing streams in basin-margin conditions. The basal Surat Basin unit, the Precipice Sandstone, is present only in the west in the subsurface (Fig. 2); it is generally thickest in the Mimosa Syncline and wedges out against basement to the east. Away from the basin margin in the west and south, a typical Evergreen-Hutton succession is developed in the subsurface. There the Evergreen Formation is a dominantly silty sequence interrupted by a well defined band containing several layers of oolitic ironstone, and the Hutton Sandstone is quartzose to sublabile sandstone.

In outcrop west of the Yarraman Block, a comparable Evergreen­ Hutton succession can still be recognised. The oolitic member (Jlo), the silty upper Evergreen member (Ile2), and the Hutton Sandstone are similar to their counterparts within the basin; the basal Evergreen member

(Ile1), however, is a coarse-grained arkosic sequence. To the south and southeast of the Yarraman Block the Marburg Sandstone of the Clarence­ Moreton Basin covers the same stratigraphic interval; here rare pelletal beds replace the oolites and no silty interval comparable with the upper Evergreen Formation is consistently developed. Northward the basal

Evergreen Member (Jle1) merges with the Jurassic sediments of the Mulgildie Basin.

The Injune Creek Group crops out poorly, and outcrop is confined to the northwest of the Sheet area. Elsewhere it is covered by Tertiary and Quaternary sediments, but exploratory drilling has delineated a roughly west-northwesterly strike. Where the Springbok Sandstone, the upper part of the Injune Creek Group, is deeply weathered in the Chinchilla area, it is indistinguishable from the Kumbarilla Beds and becomes part of that unit. The Gubberamunda Sandstone, which overlies the Injune Creek Group in the Mimosa Syncline, thins and grades laterally into the basal Orallo Formation on the east flank of the syncline, so that in outcrop in the northwest of this Sheet area, the Orallo Formation directly overlies the Injune Greek Group. The Lower Cretaceous Mooga Sandstone and Bungil Formation and the Doncaster and Coreena Members of the Wallum­ billa Formation are mappable only on the western margin of the Sheet area, and even here exposure is very poor. The Kumbarilla Beds are an out­ crop unit equivalent to the stratigraphic interval from the Springbok Sandstone to the top of the Bungil Formation. Poor outcrop, the obscuring effect of intensive deep weathering, and a lack of lithologically diagnostic • The Mimosa Syncline is a broad fold which reflects the main downwarp of the Taroom Trough. The axis of the syncline is in the Roma Sheet area to the west, and has a meridional trend.

11 TABLE 5.--CAINOZOIC ROCK UNITS

Name Thickness Environment of Major Published Age (Map Symbol) Lithology (Feet) Fossils Deposition Reference

QUATERNARY Qa Low level sand, silt, Deposition by present­ mud, gravel and soil day streams Qpc Clayey residual soils, Up to 150 Abundant invertebrate Deposition by ancestral Woods (1960) generally forming remains in the south: streams of present alluvial plains Diprotodon and other stream system mammals, birds, rep­ tiles, and fish

Qs General sand and soil Deposition by earlier cover streams of present stream system

CAJNOZOIC Cz Poorly consolidated, Sheet erosion from unbedded, very poorly topographic highs of sorted sandstone, pre-existing sediment conglomeratic sand­ stone, breccia, silt­ stone -N Czg Granite wash; felds- Up to 70 Mechanical disaggrega­ pathic sandstone with tion and sheet erosion angular quartz and of granite, with some euhedral feldspar local transport by grains streams

PLIOCENE Chinchilla Weakly consolidated 110 Abundant vertebrate Deposition from fore- Woods (1960) Sand labile sandstone grad­ fo::1ils: Euryz.ygoma runner of Condamine Tpc ing to grit and con- dunense and other River glomerate, and to mammals, crocodiles, s1ndy clay; minor tortoises, goannas. thin, well-lithified, fishes, and birds calcareous beds T Thick-bedded and 40 Sheet erosion and local cross-bedded sand- fluviatile deposition stone with minor pebbly sandstone and siltstone

MIOCENE Tmb Mainly olivine basalt 400 Extrusive and explosive Webb, Stevens, & in at least three sep- vulcanism McDougall arate flows with sub­ ( 1967) ordinate tuff and agglomerate features have rendered the sequence indivisible in terms of the formations established farther west. These formations are still recognisable by wire­ line log characteristics in the subsurface, mainly by the presence of porous intervals in the sequence which can be correlated with more westerly sand­ stone formations. Most of the Surat Basin sequence has been affected by deep weathering (see Table 4), a process requiring long tectonic and climatic stability, following the development of a pediplain. The process involves more or less complete reconstitution of the labile fraction of the rock, extensive mobilisation of existing iron, and the formation of a crust of resistant, iron­ cemented material at the top. The resulting profile consists of quartz and remnant labile grains in a tough clay matrix with mottled iron staining. It has been shown that the main period of deep weathering was pre-Miocene (Exon, Langford-Smith, & McDougall, in press). The youngest rocks affected in the Surat Basin are Lower Cretaceous. Cainozoic (Table 5) Tertiary volcanics reach a thickness of 400 feet in the southeast. They consist of extensive basalt flows, with associated tuff and agglomerate beds up to 100 feet thick. Isolated patches of volcanics, probably including some vents, are present throughout the eastern third of the Sheet area. Basalts to the south and east, with which the main basalt body is contiguous, have been dated as early Miocene by K/Ar methods (Webb et al., 1967). The Pliocene Chinchilla Sand, which is characterised by the presence of vertebrate fossils, crops out poorly as it is only weakly consolidated; outcrop is localised along the Condamine River near Chinchilla. The former exposed extent of the unit was probably much greater, as vertebrate remains from wells suggest that sediments of the same age extend at least as far as Dalby, 50 miles to the southeast. Occurrences of vertebrate fossils of Pleistocene age indicate that Pleistocene alluvium blankets much of the eastern part of the Sheet area. The plains around Durong are included in this unit, although the bulk of the alluvial deposits at depth are probably pre-Pliocene, deposited before the extrusion of the basalt.

STRUCTURE The Chinchilla Sheet area includes part of the northeastern margin of the Jurassic-Cretaceous Surat Basin. The Surat Basin sequence over­ lies Palaeozoic basement rocks in the eastern three-quarters of the Sheet area, and Bowen Basin sediments in the Taroom Trough in the western quarter (see Fig. 2). The surface of the eastern basement block dips southwest at less than 1 °, away from· outcrop in the north and east. . Outcropping rocks are metamorphics and granite of the Yarraman Block (Hill & Denmead,

13 151°30' "«"~=== ",~=-r.--:-c~-:r--r:-:-:--,-,;-- c--,.=..._..,===·-::---:-:= = ==._---::---"7- :--:---c--i 2s•oo'

0 10 20 lO KILOME:'TRES G 56 /A/4 10 20 MILES

Cttntovr o n lio•• of Jur oull: f f••1 b•Jow Cl 1moti1 Sondtto n , CI] HO /•l'•/) ~ Rewan Formotio n Oulcrop 9,0109/col bovttdoty Sv /,crop 1>o r1n dorr b •low pr• Jr1rou/c ~ 81ock""orcr Gro 11 p r1nconformily Foult 8 ocl-, Crut( Group ~ £0S1, m li'm/J of d•po•ilitM of Pr ,eip/c, Yonol Botln sediments & volc«:ll'lic,, } Sondslon• Er] a r1lol1d 11.1 1>,urfoc, P.rmlol\ ond ~to'l)' 1)'"1.bob Corb0Nlero111 rocll.t lndicol• Tinhvl w,npos /Ji on wilh dfpllt bolow n u ,• .,,, ofPI• 01.11 c ,op 1131' JutOISic 1111conlormi tf [1j Polo•oiolc 9ro"ite. , chi•t.ol\4 Qt'l1lu 0 Principol l~M Compd•d f rom oufet op , #Kplorotory ,,,,,,11,wot,r l>Orf ond u ,sml , dolo Figure Z. Pre.Jurassic palaeogeology and structure contours on base of Jurassic

1960, p. 251) in the eastern third of the area, a small tongue of the Auburn Granite to the west, and Carboniferous Yarrol Basin sediments in a graben in between. The western side of the Yarrarnan Block is faulted in places, and there is strong linear jointing in the granite, parallel to the faulting (see geological map) . McTaggart (1963a) referred to this feature as the Yarrol Thrust, and plotted its continuation in the subsurface by the study of basement types encountered in water bores to the south of the area of outcrop. Evidence of thrusting is lacking, and this feature is better regarded simply as a line of demarcation between the Yarrol Basin and a basement block which may or may not be faulted. It also approximates the zone

14 of change from Jurassic sediments of Surat Basin type to those of Clarence­ Moreton Basin type. Relationship of the feature to Yarrol Basin tectonics will only be known with further mapping to the north, so that no formal nomenclature is justified at this stage.

The western quarter of the Sheet area has been the site of active subsidence at least since the Permian and a tongue of Bowen Basin sediments is preserved in the meridional Taroom Trough (Exon, in press) which was subsiding during the Permian and Triassic. Only the eastern flank of the trough is in the Chinchilla Sheet area. The Taroom Trough sequence is overlain by a somewhat thickened Surat Basin sequence, preserved in the Mimosa Syncline. The eastern limb of the trough shows complex block faulting (Kahanoff, 1962b; United, 1964, 1966) which has affected the whole of the sedimentary pile and is visible in some places at the surface, either as faults or as strong lineaments which are probably major joints.

The regional dip of the Jurassic and Cretaceous sediments is partly the result of continuing basin subsidence; it is probably also partly due to differential uplift in the east associated with the extrusion of the basalts of the Main Range Volcanics, as dips up to 10° have been recorded in Marburg sediments onlapping the granites in the east (e.g., at grid ref. 444697).

GEOLOGICAL IDSTORY In the Carboniferous, Yarrol Basin sediments were deposited over most of the Sheet area; metamorphic rocks of the Yarraman Block probably formed topographic highs to the east. Great thicknesses of polymictic gravel, lithic sand, silt and mud, and both pyroclastic and effusive volcanics were deposited in conditions which were in part marine; limestone reefs formed in some areas. I~ response to east-west compression the sediments were strongly but openly folded to form the Yarrol Basin, and granite was intruded in the east and central north, probably during the Permian. Uplift of basement blocks continued into the Lower Mesozoic, resulting in the formation of a graben to the north floored by the Carboniferous sediments. Rhyolite dyke swarms invaded the upper levels of the eastern granite, probably in the Permian. Abundant basic dykes cut the Auburn Granite; a few penetrated the granite and the Carboniferous sequence in the east.

In the Lower Permian, andesitic and dacitic tuffs and flows (Camboon Andesite) were laid down in the north and west of the Sheet area. The downwarping of the Taroom Trough began in later Lower Permian time and thousands of fe.et of both marine and freshwater elastics (Back Creek Group), with some pyroclastics, were deposited. The sea finally receded in the Upper Permian, although downwarping of the trough continued and

15 the coal measures and tuffaceous elastics of the Blackwater Group were laid down; conditions in this area were then almost entirely continental until the Lower Cretaceous.

A long period of aridity and steady subsidence in the Trough allowed the accumulation of over 10,000 feet of red beds (Rewan Formation) during the Triassic. Climatic changes, and possibly uplift of source areas, caused rejuvenation of the drainage system and coarse stream sediments of the Clematis Sandstone were deposited. Uplift at the close of the Triassic allowed extensive bevelling of pre-existing sediments.

Deposition resumed in the south and west in early Lower Jurassic times, when the clean quartzose sands of the lower Precipice Sandstone were laid down from fast-flowing streams eroding granitic terrain in the north and east; gradients lessened in late Precipice time, and several hun­ dred feet of silty back-swamp deposits were laid down over a wide area. Similar deposition continued into lower Evergreen time in areas remote from the basin margin; with further decline of the energy of the depositional environment, silt became the dominant sedimentary type, deposited in swamps and lakes.

At the basin margin, arkoses of the lower Evergreen and basal Marburg were deposited directly on Palaeozoic basement. The Yarraman Block remained a topographically high area throughout the Lower Jurassic, so that there was continuous deposition in the southeast of feldspathic sands (Marburg Sandstone) from a fairly vigorous stream system. To the west, uplift ceased, energy in the depositional environment decreased, and con­ ditions were then fairly uniform throughout the area of deposition of the Evergreen Formation; a marine incursion, or at least establishment of brackish water conditions, allowed the formation of oolites and the prolifera­ tion of acritarchs in a sequence of fine-grained sand and silt. In upper Evergreen times in the area west of the Yarraman Block, silt and very fine sand were deposited by a system of meandering streams. Faster-flowing streams in Hutton times led to the deposition of quartzose sand in the west, while deposition of feldspathic sands of the Marburg Sandstone continue.i m the east. In the Middle Jurassic a coal-measure sequence including lithic sand, silt, and mud (lnjune Creek Group) was laid down by streams, and in lakes and swamps. Andesitic vulcanism provided much of the detritus. In the Upper Jurassic, there was continued deposition east of the Mimosa Syncline from streams and lakes, with some andesitic ash falls, resulting in about 500 feet of labile sand and silt (Orallo Formation). In the Mimosa Syncline, a rejuvenated stream system deposited several hundred feet of cleaner sand­ stone (Gubberamunda Sandstone); stream gradients then declined once more, and the "fine-grained sediments of the Orallo Formation were deposited in this area too.

16 During the Lower Cretaceous freshwater sediments of the Mooga Sandstone were covered by a marine transgression marked by the strand­ line deposits of the Bungil Formation. Marine mud of the Doncaster Member and coastal silt and sand of the Coreena Member were then deposited.

After Lower Cretaceous time, there was a period of prolonged tectonic and climatic stability, in which the Jurassic and Cretaceous sediments were deeply weathered. The Condamine River at this time probably flowed north and then northeast to the sea and deposited the sediments which now underlie the Durong Plain. This drainage system was disturbed during the period of instability associated with the exten­ sive extrusion of the basalts of the Main Range Volcanics in the early Miocene, resulting in the reversal of flow of the Condamine's northern extension and the establishment of the Boyne as an independent river system. The Yarraman Block was probably uplifted and tilted slightly at this time. As erosion proceeded, the stream divide migrated to its present position. The Chinchilla Sand was deposited by the Condamine River during Pliocene times. Pleistocene sediments were deposited in an extensive area, north of the present river channel, in the east. The granite mass in the east continued to erode and arkosic sediments were deposited near­ by. Throughout the area, the deeply weathered material has been exten sively stripped by late Cainozoic and Recent erosion. Ferruginization of weathered sediments still persists in much of the area.

ECONOMIC GEOLOGY Water Surface water supplies are inadequate, except where the Condamine River provides a reliable source of stock water, and supports some local irrigation. Other streams generally flow intermittently. Throughout most of the Sheet area, earth tanks and dams are the principal mode of water storage. Rainfall is light and unreliable, so that underground supplies are utilized extensively. Aquifers in arenites throughout the Jurassic sequence are tapped, the main supplies coming from the Hutton Sandstone. Bores are generally shallow (seldom more than 1000 feet deep) and subartesian; the average rate of production is much less than is typical for the deeper bores of the Surat Basin proper, which tap the same aquifers. Bentonite A deposit of good quality bentonite was discovered in a sca.rp north of Miles on the Leichhardt Highway (grid ref. 299725). The discovery was reported in detail by Exon & Duff (1968). Five beds up to 5 feet thick crop out in the scarp and the road cutting; three beds up to 2 feet thick were encountered over the same interval in shallow drill holes

17 (BMR Chinchilla I, 2, and 2a) 500 yards south of the scarp. The bentonites are derived from ash falls which have been preserved only in back swamp deposits; they occur in the uppermost Injune Creek or lowermost Orallo Formation. Chemical and physical analyses show that the bentonite is sodium montmorillonite and has potential as a base for drilling mud and possibly for pelletising iron ore. A mining company is currently evaluating the deposit. Clay A brickworks at Chinchilla uses clay from a deep weathering profile developed on Orallo or lnjune Creek sediments (grid ref. 357683); a report by Hueber & Holland (1952) concluded that the clay was suitable for the manufacture of extruded and wire-cut bricks and agricultural pipes. In the same investigation, clay from deeply weathered (probably Evergreen) sediments on Waterloo Creek near Durong and deeply weathered Ever­ green clay from Burra Burri were examined; the former was found suitable for bricks, the latter for bricks and pottery. Coal Coal occurs commonly throughout the lnjune Creek Group; in general the seams are fairly thin (mostly less than l O feet thick) and consist of finely interbedded bands of coal and shale. Several attempts have been made to establish coal mines in the southern part of the Chinchilla Sheet area, along the Western Railway (see Cameron, 1910; Marks, 1910; Cribb, 1944), but these have failed because of the lack of continuous seams of adequate thickness. The coal is high in volatiles, as shown by the numerous reports of occurrences of occluded coal gas (see, for example, Gray, 1967); however, occurrences are scattered, and the volumes of gas are not commercially significant. Construction materials The Wambo Shire Council quarries basalt for road metal in the south­ eastern corner of the Chinchilla Sheet area at Kings Pit north of Bell (grid ref. 453660) and Malakoff Quarry east of Kimbour (grid ref. 431654). The basalt in this area was extruded onto an irregular surface in at least three flows, with intervening periods of weathering; the vertical extent of unweathered basalt varies erratically, and consequently the amount available for economic quarrying is small compared with the total area extent of the flows. The valley and course of the Boyne River contain extensive unworked sand and gravel deposits. Iron ore An investigation of the potential of the oolitic ironstone member of the Evergreen Formation was carried out by Consolidated Zinc Pty Ltd in the adjacent Mundubbera Sheet area (Urquhart, 1962) . The iron content

18 of the oolitic limonite itself averaged 40 per cent. Beneficiation tests were not successful and the deposits were considered uneconomic. As Urquhart had reconnoitred the Chinchilla Sheet area before concentrating on the area to the north, it is unlikely that economic deposits exist here. Just west of the Yarraman Block (grid ref. 416751) two seams of ironstone three feet thick and ten feet apart are present in a scarp. Copper There is copper mineralisation in Carboniferous rocks (mainly sheared sediments in tuff) in the far north of the Chinchilla Sheet area (grid ref. 417760). Remains of old workings are still to be seen, but the Queensland Department of Mines has no record of copper mining there. A sample of green sandstone and siltstone, veined with quartz and sheared, from a locality at grid reference 416764, gave, on analysis, 6900 parts per million of copper (D. Bennett, Appendix in Exon et al., 1968). Tin Alluvial tin mining on Rocky Creek (grid ref. 428766), begun in 1903, was carried on sporadically for many years. Reports by Ball (1904, 1912) and Morton (1924) show that the deposits are very small and generally uneconomic. Rocky Creek erodes the Yarraman Block granite whence the tin is derived. Petroleum Eighteen exploratory wells have been drilled in the Sheet area. Gas shows were reported from the two earliest holes (Table 2) but these probably represented occluded methane gas in coal of the Injune Creek Group. The only other hydrocarbon show was gassy water from the Precipice Sand­ stone in UK.A Mackie 1 in the south of the Sheet area. Prospects are discouraging; most promising structures in the Mimosa Syncline have been drilled unsuccessfully, and in the shelf area close proximity to areas of outcrop would probably have allowed hydrocarbons to migrate and escape at the surface.

19 BIBLIOGRAPHY • Operation subsidized under Petroleum Search Subsidy Acts; copies available for inspection and copying at the Bureau of Mineral Resources, Caoberra, and the Geological Survey of Queensland, Brisbane. t Unpublished internal company report, on open file at the Geological Survey of Queensland, Brisbane. •AERO SERVICE CORPORATION, 1963-lnterpretation report on airborne magnetometer survey of the Surat-Bowen Basin areas, Eastern Australia (unpubl.). ALLEN, R . J., 1962-62-year search for oil in Queensland is still unavailing but .... Oil Gas J., 60(35), 144-7. BALL, L. C., 1904-The late discovery of tinstone, Burnett district. Qld Govt Min. J., 5(2), 62. BALL, L. C., 1912-Occurrence of tinstone in the Burnett district. Ibid. 13(3), 107-11. BALL, L.C., 1928a-Report on search for oil. Ibid., 29, 394-7. BALL, L. C., 1928b--Report on a visit to Roma and district. Ibid., 29, 398-9. BALL, L. C., 1931-Report on search for oil (Guluguba). Ibid., 32, 89-90. BALL, L. C., 1945-Oil shales in Queensland. Ibid., 46, 74-5. BASTIAN, L. V., 1965-PetrologicaJ report on the basement to Lower Jurassic sections of some subsidized wells in the Surat Basin. Bur. Miner. Resour. Aust. Ree. 1965/120 (unpubl.). BASTIAN, L. V., and ARMAN, M., 1965-Petrographic notes on some Triassic sediments in UKA Wandoan No. 1 well and in adjoining areas. Ibid., 1965/227 (unpubl.). BRYAN, W. H., and JoNES, 0. A., 1946-The geological history of Queensland. A stratigraphic outline. Dep. Geol. Univ. Qld Pap., 2(12), 1-103. BRYAN, W. H., and WHITEHOUSE, F. W., 1926-Later palaeogeography of Queensland. Proc. Roy. Soc. Qld, 38, 103-14. BMR, 1965-Bouguer anomalies, Chinchilla 1 :250,000 Sheet area, Queensland. Bur. Miner. Resour. Aust. Map G55/B2-9. BURGER, D., 1968-Stratigraphy and palynology of Upper Mesozoic sections in the Surat Basin, Queensland. Bur. Miner. Resour. Aust. Ree. 1968/24 (unpubl.). CAMERON, W. E., 1910--Coal near Dalby. Geol. Surv. Qld Pub/. 235(2). tCGG, 1963-Seismic re-interpretation of the Chinchilla area PPP 708, Comp. Gen. Geophysique (unpubl.). CASEY, D. J., GRAY, A. R .. and REISER, R . F., 1968-Comparison of the Lower Jurassic strata of the Surat and Moreton Basins. Qld Govt Min. J., 69. CRIBB, H. G. S., 1944-Coal occurrences at Warra. Qld Govt Min. J., 45, 155. tCuNDILL, MEYERS and AsSOCJATEs, 1966-Geological report on ATP 112P, Surat Basin, Queensland. For Condamine Oil Ltd (unpubl.). DARBY, F., 1965-Gravity readings along seismic traverses, central and southern Queens­ land, 1963. Bur. Miner. Resour. Aust. Ree. 1965/91 (unpubl.) . DAY, R. W., 1964-Stratigraphy of the Roma-Wallumbilla area. Geol. Surv. Qld Pub!. 318. DE JERSEY, N. J., and PATEN, R. J., 1963-Palynology of samples from the Cadarga Creek area, Surat Basin (southern Queensland). Geol. Surv. Q/d Ree. 1963/4 (unpubl.). DE JERSEY, N. J., and PATEN, R. J., 1964-Jurassic spores and pollen grains from the Surat Basin. Geol. Surv. Qld Pub/. 322. DENMEAD, A. K., 1938-The Cracow gold.field. Qld Govt Min. J., 39, 368-76. EVANS, P. R., 1966a-Mesozoic stratigraphic palynology in Australia. Aust. Oil Gas J., 12, 6. EVANS, P. R., in pres-Upper Carboniferous and Permian palynological stages and their distribution in eastern Australia. Proc. First /nt. Sym. Gondwana Strat. and Palaeont. Mar del Plata, Argentina, 1967. ExoN, N. F., 1966-Revised Jurassic to Lower Cretaceous stratigraphy in the south­ east Eromanga Basin, Queensland. Qld Govt Min. J. , 67, 232-8. EXON, N. F., in press--Roma, Qld-1:250,000 Geological Series. Bur. Miner. Resour. Aust. exp/an. Notes SG/55-12. 20 ExoN, N. F., and DuFF, P. G., 1968- Jurassic bentonite from the Miles district, Queens­ land. Bur. Miner. Resour. Aust. R ee. 1968/49 (unpubl.). ExoN, N. F., LANGFORD-SMITH, T. W., and McDOUGALL, I., in press-The age and geomorphic correlations of deep-weathering profiles, silcrete and basalt in the Roma-Amby region, Queensland. J. geol. Soc. Aust. ExoN, N. F., MILLIGAN, E. N., and DAY, R. W., 1967-Age of the duricrust in southern Queensland. Aust. J. Sci. , 30(3), 110. EXON, N. F., and VINE, R. R., 1969-Revised nomenclature of the 'Blythesdale ' sequence. Qld Govt Min. /., 70. ExoN, N. F., REISER, R . F., JENSEN, A. R., BURGER, D., and THOMAS, B. M ., 1968- The geology of the Chinchilla 1 :250,000 Sheet area, southern Queensland. Bur. Miner. Resour. Aust. Ree. 1968/53. *FJEL

21 LANGFORD-SMITH, T., D URY, G. H., and McDouGALL, I., 1966--Dating the duricrust in southern Queensland. Aust. J. Sci., 29(3), 79-80. LANGRON, W. J., and VAN SoN, J. R. H. , 1967- Regional gravity survey, northeastern New South Wales and southeastem Queensland, 1960-1961. Bur. Miner. Resour. Aust Ree 1967/12 (unpubl.). LoNSDALE, G. F., 1965--Southem Queensland contract reconnaissance gravity survey using helicopters, 1964. Bur. Miner. Resour. Aust. Ree. 1965/251 (unpubl.). MACK, J. E., Jnr, 1963-Reconnaissance geology of the Surat Basin, Queensland and New South Wales. Bur. Miner. Resour. Aust. Petrol. Search Subs. Acts Pub/. 40. tMACK, J. E., Jnr, 1964--Subsurface geology of the Undulla Nose, ATP 57P, Queens­ land, Australia. Union Oil Devel. gen. Rep. 16 (unpubl.) . tMAcK, J. E., Jnr, 1965-Geological report on subsidized drilling operations UKA Giligulgul No. 1, UKA Weringa No. 1, Miles Wandoan district, Bowen-Surat Basin, ATP 57P. Queensland, Australia. Ibid. 17 (unpubl.). McQuEEN, A. M. , and WARNER, D. F., 1962-Final seismic survey report of the Chin­ chilla area PPP 708, State of Queensland, by Austral Geo. Prospectors. Condamine Oil Ltd (unpubl.). MCTAGGART, N. R., 1963a- Geology of the northeastem Surat Basin. Aust. Oil Gas J., 9(12), 44-52. McTAGGART, N. R., 1963b--The Mesozoic sequence in the Lockyer-Marburg area, southeast Queensland. Proc. Roy. Soc. Qld, 73 (7), 93-104. *MCTAGGART, N. R., 1964-Condamine Canaan No. 1 by W. D. Mott and Associates. Completion report. Condamine Oil Ltd (unpubl.). MARKS, E. 0 ., 1910-Coal near Chinchilla. Geol. Surv. Qld Pub/. 235. *MEYERS, N. A., 1965-Phillips-Sunray Yarrala No. 1. Completion rep. (unpubl.). t MEYERS, N . A., 1966--Geological report on ATP 112P, Surat Basin Queensland by Cundill, Meyers and Associates. For Condamine Oil Ltd (unpubl.). MoLLAN, R. G., DICKINS, J. M., ExoN, N. F., and KIRKEGAARD, A. G., 1969-The geology of the Springsure I :250,000 Sheet area, Queensland. Bur. Miner. Resour. Aust. Rep. 123. MOLLAN, R. G., FORBES , V. R. , JENSEN, A. R., EXON, N. F., and GREGORY, C. M ., in press-Geology of the Eddystone and Taroom 1:250,000 Sheet areas and the western part of the Mundubbera l :250,000 Sheet area. Bur. Miner. Resour. Aust. Rep. MoLLAN, R . G., KIRKEGAARD, A. G ., EXON , N. F., and DICKINS, J. M., 1964--Note on the Permian rocks of the Springsure area and proposal of a new name, Peawaddy Formation. Qld Govt Min. J., 65, 576-81. MORTON, C. C., 1924-Rocky Creek Syndicate's Prospecting area, Rocky Creek. Qld Govt Min. J., 25 (9), 325-9. Mon, W. D., 1952-0il in Queensland. Qld Govt Min. J. , 53, 848. tMorr, W. D., and Assoc1ATES, 1963-Condamine Oil Ltd Speculation No. 1 well. Completion rep. (unpubl.) tOLSoN, K. A., 1963--Surface geolo,gy and shot hole drilling in the Charley's Creek area, ATP 71P, Queensland. Phillips Petroleum Co. (unpubl.). PATEN, R. J., 1967-Microfloral distribution in the Lower Jurassic Evergreen Forma­ tion of the Boxvale area, Queensland. Qld Govt Min. J., 68, 345-9. PowER, P. E. , and DEVINE, S. B., 1968--Some amendments of the Jurassic stratigraphic nomenclature in the Great Artesian Basin. Qld. Govt. Min. J., 59, 194-8. QUEENSLAND MINES DEPT, 1965-0il drilling in Queensland, 1965. Ann. Rep. Qld Mines Dep., 1965. QUEENSLAND MINES DEPT. 1966-0il drilling in Queensland, 1966. Ibid. 1966. REEVES, F., 1947-Geology of Roma district, Queensland, Australia. Bull. Amer. Ass. Petrol. Geol., 34, 1341-71. REID, J. H., 1929-Marginal formation of the Great Artesian Basin in Queensland. Rep. 5th Interstate Con/. artesian Water, Sydney, 1928, 30-32. RtVEREAU, J. C., 1966--Report on photo-interpretation of Mitchell (southern half), Roma and Chinchilla 1 :250,000 scale sheets, Queensland. Bur. Miner. Resour. Aust. Ree. 1966/100 (unpubl.). tSCKNEEBERGER, W. F ., 1951-Report on the geology of the Cracow-Prospect Creek area and the Monto-Yarrol Basin. Shell (Qld) Devel. Pty Ltd Rep. (unpubl.). 22 ScoRER, J. D. T., 1966-A summary of pressures and fluid data from wells drilled in the Surat Basin, with a preliminary discussion of the hydro-dynamics of the basin. Bur. Miner. Resour. Aust. Ree. 1966/102 (unpubl.). tSQ~ 1952-General report on investigations and operations carried out by the l.:ompany in the search for oil in Queensland, 1940-1951. Shell (Qld) Devel. Pty Ltd (unpubl.). STAINES, H. R. E., 1964-Stratigraphic nomenclature of Bundamba Group in the Ipswich area. Qld Govt Min. J., 65, 33-5. tSTURMFELs, E. K., 1954-0il potentialities of PPP No. 682 near Miles, Queensland. Murilla Oil Ltd (unpubl.). TlssoT, B., 1963a-Correlation of the Jurassic and Middle-Upper Triassic in the Bowen­ Surat Basin. IFP Mission in Australia Prog. Rep. 5, AUS/66 (unpubl.). nssoT, B., 1963~orrelations of the Permo-Triassic in the Bowen-Surat Basin. Ibid. 8, AUS/80 (unpubl.). UK.A, 1964-Summary of data and results Surat Basin, Queensland: UK.A Wandoan No. 1, UK.A Burunga No. 1. Bur. Miner. Resour. Aust. Petrol. Search Subs. Acts Publ. 53. UNION, 1960-Final report and interpretation of airborne magnetometer survey of Surat Basin, Queensland, Union Oil Devel. Corp. (unpubl.). UNION, 1963-UKA Mackie No. I, Preliminary Final Rep. Ibid. (unpubl.). UNION, 1964a-UKA Picurda No. 1. Ibid. (unpubl.). UNION, 1964b--UKA Conloi No. 1. Ibid. (unpubl.). UNION, 1964c-UKA Gurulmundi No. 1. Ibid. (unpubl.). UNION, 1965-UKA Weringa No. 1. Ibid. (unpubl.). UNITED, 1964-Final report on seismic survey of the Moonie River area. United Geophys. Corp. for Union Oil Devel. Corp. (unpubl.). •UNITED, 1966-Final report on Condamine seismic survey. Ibid. (unpubl.). t URQUHART, G., 1962-Report on low grade bedded ironstone deposits in the Marburg­ Bundamba strata of Queensland. Consol. Zinc Pty Ltd (Geol. Surv. Qld A.uth. Rep. 840) (unpubl.). V1NE, R. R ., and DAY, R . W., 1965--Nomenclature of the Rolling Downs Group, northern Eromanga Basin. Qld Govl Min. J., 66, 416-21. Y1NE, R. R., DAY, R. W., MILLIGAN, E. N., CASEY, D. J., GALLOWAY, M. C., and ExoN, N. F., 1967-Revision of the nomenclature of the Rolling Downs Group in the Eromanga and Surat Basins. Q/d Govt Min. J., 68, 144-51. WALKOM, A . B., 1918-Mesozoic floras of Queensland, Part II. Geol. Surv. Qld Pub/. 262 . . •WARNER, D. F., and KLAUDT, B. J., 1963-Final report on Barakula seismic survey, PPP 708, State of Queensland. B. 0. C. Australia Ltd (unpubl.). WEBB, A. W. and McDOUGALL, I., 1968- The geochronology of the igneous rocks of eastern Queensland. J. geo/. Soc. Aust., 15(2), 313-47. WEBB, A. W., STEVENS, N. C., and McDOUGALL, I., 1967-Isotopic age determinations on Tertiary volcanic rocks and intrusives of southeast Queensland. Proc. Roy. Soc. Qld, 79 (7). WHITE, MARY E., 1967- Report on 1967 collection of plant fossils from the Surat Basin. Bur. Miner. Resour. Aust. Ree. 1967/162 (unpubl.). WHITEHOUSE, F. W., 1928-The correlation of the marine Cretaceous deposits of Australia. Aust. Ass. Adv. Sci. Rep. 18, 275-80. WHITEHOUSE, F. W., 1952-The Mesozoic environments of Queensland. Ibid., 29. 83-106. WHITEHOUSE, F. W., 1954-The geology of the Queensland portion of the Great Australian Artesian Basin. Appendix G in Artesian Water Supplies in Queensland. Dept Co-ord. Gen. Public Works, Qld. WOODS, J. T., 1956-The skull of Thylacoleo carni/ex. Mem. Qld Mus., 13, 177-93. WOODS, J. T., 1960-Fossiliferous ftuviatile and cave deposits. J. geol. Soc. Aust., 7, 393-403.

23 T. 1. HuoHES, Government Printer, Tasmania. (15315 14)