The Canning Basin is the largest sedimentary basin in Western Australia, and the second largest basin in Australia. Excluding the seaward extension of the basin on the Rowley Shelf, and the southern part of the basin, south of Lat. 24° S, which are unknown, its area is 175,000 square miles, roughly the size of Spain. The sediments overlie a Precambrian basement, which in most areas consists of crystalline rock (gneiss, schist), and in the north-eastern part of unaltered sedimentary rocks. The Bureau started field work in the Canning Basin in 1947 and continued every year up to 1958. This work was carried out by geological parties equipped with land vehicles (1947-56) and with a helicopter (1957), by seismic and gravity parties, by an airborne magnetic party, and by a stratigraphical drilling party (1955-58). All work was based on air photographs, at a scale of 1:50,000, prepared by the R.A.A.F. This bulletin incorporates the results of all these surveys. The main published material is: Traves, Casey, & Wells (1957),* Guppy, Lindner, Rattigan, & Casey (1958), and Brunnschweiler (1954 and 1957). Geophysical work is described in unpublished records. Fossils collected by Bureau parties in the Fitzroy Basin have been the subjects of several monographs, which have been published by the Bureau. The first study of plant fossils from the Canning Basin is by White (Appendix 6). 4-mile geological series maps and explanatory notes have been published for Derby, Lennard River, Mount Anderson, Noonkanbah, Yarrie, Anketell, Paterson Range, and Tabletop; and maps and explanatory notes of Mount Bannerman, Billiluna, Lucas, Cornish, and Stansmore will be published shortly. Other major reports on the area are included in McWhae, Playford, Lindner, Glenister, & Balme (1958), Reeves (1951), and the numerous papers published by Teichert (1941, 1947, 1949, and 1950). The first attempt at compiling a geology of the Canning Basin was made by Reeves (1949, unpubl.). Photographic cover extends to 24° S, and the examination of the basin south of 24° S is postponed until air photographs are prepared. This Bulletin thus deals with the (greater) part of the Canning Basin that lies north of 24° S.

Between February and April 1961 the Bureau of Mineral Resources, Geology and Geophysics made a seismic survey in the Rosedale area of the Latrobe Valley, partly at the request of the State Electricity Commission of Victoria to provide more information about the brown coal measures in this area, and partly in order to test the Bureau's latest seismic recording equipment. One traverse, combining both reflection and refraction profiling techniques, was run south from the A.P.M. No.1 bore at Rosedale as far as Merrimans Creek, and a second traverse was run west from the bore as far as Toongabbie. Results show that the maximum thickness of the Tertiary sequence is about 3000 ft and that it thins gradually to 1000 ft at Toongabbie and rapidly to about 750 ft on the Baragwanath Anticline. It is shown that early Tertiary deposits were laid over the whole area but have been uplifted and partly eroded in late Tertiary or post-Tertiary times in the Toongabbie and Baragwanath areas, but the main syncline sank and accumulated thick Tertiary sediments. Results show alao that on the northern flank of the Baragwanath Anticline where crossed by the seismic lines the Tertiary and Jurassic sediments are steeply folded but not necessarily faulted. No positive information was obtained below 4500 ft but long refraction shots suggest that a high-velocity basement does not exist at a depth less than 12,000 ft.

Samphire Marsh No. 1 Well was drilled to a total depth of 6664 feet as a stratigraphic and structural test in the South Canning Basin. The drill passed through 120 feet of Quaternary silt and limestone, 2124 feet of Mesozoic sandstone and siltstone, 1811 feet of Permian marine beds, partly of glacial origin, and 2541 feet of Lower Ordovician shale with sandstone at the base. The drill encountered Precambrian granite at 6610 feet, confirming the geophysical estimate of depth to basement. None of the sediments present in the well are considered likely to be a source for hydrocarbon accumulations. No signs of hydrocarbons were seen in this well.

The Innamincka No. 1 test well, drilled by Delhi Australian Petroleum Ltd, Frome Broken Hill Company Pty Ltd, and Santos Limited, in the north-east corner of South Australia, penetrated the strata below the surface in the deeper portion of the Great Australian Artesian Basin to a total depth of 12,637 feet. The test was begun late in March, 1959, using a National 130 drilling rig operated by Delta Drilling Company. The operation, under supervision of drilling, engineering, and geological personnel of Delhi Australian Petroleum Ltd, involved an extensiveprogranune to obtain technical data relative to the occurrence of hydrocarbons in the strata cut by the drill bit, as well as stratigraphical information concerning the geological history of the area. Included in the operation was a full complement of logging, coring, and testing programmes provided and conducted by the operating Company and their Contractors. Innamincka No. 1 established the presence of at least 6,723 feet of Mesozoic sediments, as well as 5,914 feet of sediments of Palaeozoic age at the wellsite. Several minor showings of hydrocarbons were encountered within the Mesozoic sequence below 3,928 feet in nonmarine sediments; however, after thorough examination and testing, the shows proved inconsequential. Several zones within the interval 4,390 feet to 7,050 feet evidenced physical qualities such that the rock could be classified as mechanically favourable as reservoir type rock, but an analysis of the sediments suggested that their origin was not favourable as hydrocarbon source rocks. The intervals 0 feet to 4,390 feet and 7,050 feet to 12,637 feet did not suggest qualities of either source-bed or reservoir type rocks. The well was completed in late November, 1959 as an artesian water well from the Blythesdale Formation through perforations between 4,390 feet to 4,560 feet.

The Betoota No. 1 well was drilled by Delhi Australian Petroleum Ltd, Frome-Broken Hill Company Pty Ltd, and Santos Limited, in far southwest Queensland to a total depth of 9,824 feet. Drilling was commenced on 22nd December 1959 and the well was completed on 18th April 1960 as a dry hole. The rig used was a National 130 owned by Delta Drilling Company. Delhi Australian Petroleum Ltd, as the operating company, supplied the supervisory, engineering, and geological personnel. A comprehensive programme to obtain all data relative to the hydrocarbon potential of the strata penetrated by the drill bit and stratigraphic information concerning the geological history of the area was diligently carried out. The operation also provided for a complete programme of electric and mud logging, testing and coring, carried out by the operating company and their contracted service companies. The Betoota No. 1 well established the presence of 5,757 feet of Mesozoic strata overlying 4,067 feet of sediments of probable Palaeozoic age at the site of the bore hole. Several showings of hydrocarbons were detected in sediments between 4,400 feet and 5,757 feet. Mter testing and examination of all evidence, they were considered to be noncommercial. From 3,450 feet to 5,757 feet some zones exhibiting very good porosity were encountered, but all were found to be water-bearing. Shales of both marine and brackishwater origin, regarded as suitable source rocks, occurred in the well between 1,350 feet and 3,245 feet and between 5,000 feet and 5,757 feet. The rest of the section penetrated was composed of sediments whose origin did not suggest conditions of accumulation likely to foster the generation of fluid hydrocarbons.

Thangoo No. lA well was drilled as a result of mechanical difficulties encountered at the drilled depth of 3 ,475 feet in Thangoo No. 1 well which were insurmountable and prevented further operations on this well. Total loss of circulation at 3,475 feet in Thangoo No. 1 well resulted in unexpected total collapse of the hole below the 10 3/4" casing in a section of friable sandstone and conglomerate (Grant Formation). In Thangoo No. lA well these formations were cased off. A lost circulation zone was tested for potential hydrocarbon production and found to contain water only. The well was drilled to 5,429 feet into basement rocks (programmed depth 4,500 feet). Excellent hole control was maintained to total depth by drilling below the 16" conductor shoe with high pH, low shear and waterloss, freshwater mud. The 1,366 feet of Mesozoic and 1,377 feet of Permian section in Thangoo No. lA closely resemble that of Thangoo No. 1. The Ordovician section is 2,318 feet thick, consisting of 695 feet of Goldwyer Formation (new name) and 1,623 feet of Thangoo Limestone (amended name). Basement, consisting of Precambrian phyllite , was encountered at 5,100 feet in Thangoo No. lA. Traces of oil were observed throughout the Ordovician section. Oil shows are confined predominantly to vuggy veins of coarse crystalline dolomite. A minor show was also observed in the sandstone of the basal unit of the Thangoo Limestone. A porous zone within the Thangoo Limestone, causing some lost circulation, appeared at about 3,670 feet in Thangoo No. lA. A formation test of this zone recovered only brackish water (11,999 ppm. total salts) with no signs of oil or gas. It is possible that the small shows of oil in the Thangoo Limestone are retained by the impervious Goldwyer Formation, as no shows were present in the Roebuck Bay and Dampier Downs wells, where porous Permian rocks directly overlie the Thangoo Limestone. The correlation of the sections of the Thangoo Limestone in all the exploratory wells on the Broome Platform indicates that the Thangoo No. lA well occupies a low structural position. Consequently the objectives of testing the structure in the Ordovician and Permian Grant Formation were not achieved. The chances of finding commercial oil accumulations in the Ordovician section of the South Canning Basin in the vicinity of Thangoo Nos. 1 and lA are very small at this time, because of the low source rock potential and flushing by meteoric waters of the Thangoo Limestone, the lack of porosity in the Goldwyer Formation, and the difficulties experienced in resolVing the structure of the Ordovician with present seismic methods.

A reconnaissance seismic survey, subsidised by the Commonwealth of Australia, was made for Phillips Petroleum Company of Bartlesville, Oklahoma, D.S.A. and Sunray Mid-Continent Oil Company of Tulsa, Oldahoma, D.S.A. by Petty Geophysical Engineering Company of San Antonio, Texas. This survey was located within Authority to Prospect 72P in the Quilpie-Thargomindah-Charleville area of South-western Queensland. The purpose of the survey was to obtain information on the regional geology beneath the Mesozoic formations of the Great Artesian Basin north and west of the Eulo Shelf. Three deep structural basins beneath the sub-Mesozoic unconformity are indicated.

The Barlee No. 1 Well was drilled with WAPET's National 100 rig to the total depth of 8101 feet. Below a thin cover of the surface sand, 1562 feet of Mesozoic sediments were encountered, and drilled to the depth of 1594 feet. These sediments are represented by the Broome Sandstone (Lower Cretaceous) and Jurassic rocks, consisting of Jarlemai Siltstone, Alexander Formation, and Wallal Sandstone. The Jarlemai Siltstone interval which is 850 feet thick, is the thickest section of this formation which has been drilled in the Canning Basin. Unconformably below Mesozoic sediments, a uniform section of Carboniferous rocks was encountered and drilled to the total depth. All 6507 feet of the Carboniferous section are included in the Anderson Formation, to which an Upper Carboniferous age is tentatively assigned. In the lower part of the formation (7825 - 7856 feet) an intrusive body of dolerite was encountered. Some induration was observed in rocks adjacent to the intrusion. The well was abandoned in moderately porous sandstone beds of the Anderson Formation. Average dips of 20 degrees were observed in cores and recorded by the dipmeter survey in the Carboniferous section. The dipmeter survey shows that the well was located on the northern flank of the Barlee Anticline. Some very slight shows of gas were present in the sandstone beds of the Anderson Formation. Below 5600 feet some sandstone beds contained impregnations of black, rubbery bituminous material - very probably oil residue. No signs of live oil were observed in the well. The drilling results indicate that the Barlee No. 1 Well (like Fraser River No. 1) is located in the deep Fitzroy Trough on a structure originated by an igneous intrusion. The prospective beds of Ordovician, Devonian, and Lower Carboniferous rocks are buried under the thick cover of the unprospective Upper Carboniferous sediments and probably are intruded by igneous rocks. It seems likely that the sediments of the Fitzroy Trough in the Barlee area extend south as far as the Darnpier Fault; thus the Dampier Fault in the western part of the Canning Basin may replace the Fenton Fault, which dies out before reaching the Dampier Land area. The concept of the Jurgurra Terrace still remains valid, but only for the eastern part as shown on Plate .No. 1.

This report refers to seismic work carried out in the Puri area of Papua by Seismograph Service Ltd. for Australasian Petroleum Co. Pty. Ltd. during the period 6th May - 15th December, 1959. The objective ofthe survey was to determine the structural pattern of the Tertiary limestones in order to define any closed structures that may have economic oil accumulations. Altogether some 75 miles of continuous reflection traverses were observed and also a single refraction in-line profile of two spreads. An anticlinal feature was observed along one line but as there was no evidence of any significant pitch reversal along the strike line it seems there is no structure worth drilling in the area south of the Puri and Kereru Anticlines. The overall quality of the reflection data was poor but was considered adequate to disprove the presence of any major closed structures.

This report covers gravity survey work conducted by Mines Administration Pty. Limited for Associated Freney Oil Fields N. L. during the period 20th June to 31st July 1959. The survey was conducted in conjunction with the seismic survey carried out by the Bureau of Mineral Resources. The purpose of the work was to define at depth the limits of the Cooroorah Anticline, Central Queensland. Gravity values were observed and plotted over the whole of the Cooroorah area, and, in particular, over the Cooroorah Anticline. These values indicate a broad gravity '''low'' south of the Mackenzie River and west of Bluff. This is confirmed by the previous regional gravity survey of 1958. Over the Big Churchyard Culmination of the Cooroorah Anticline the gravity gradient reverses. The axis of this reversal is displaced approximately 1 1/4 miles north-west from the axis of the Cooroorah Anticline. The seismic survey shows that the structure at depth is closely conformable with the surface structure so it appears from this displacement of gravity and geological axes that the gravity "high" is due to some deep-seated density variation.