An area of 304 square km was taken up by SAPEX to allow it to evaluate afresh known sub-bituminous coal measures in the Permian Mount Toondina Formation that constitute the Weedina coal deposit. This deposit, located ~90 km north-east of Coober Pedy, was discovered by Getty Oil Development Co. Ltd in 1984, but later on its tenure was acquired by Cyprus Australia Coal Company. Until 1990, past exploratory drilling for delineating and evaluating the deposit had involved a total penetration of 24,222 m in 92 holes. This work showed that the deposit comprises a 150 m thick coal bearing zone which includes 6 major and several minor coal seams, which occurs within a north to northwest trending syncline. The seams, which occupy the upper part of the Mount Toondina Formation and are interbedded with siltstones, carbonaceous mudstones and minor sandstones, range in thickness between 2 m and 8 m, with a maximum cumulative total thickness of 35 m. The shallowest seam lies at depths between 114 m (hole 8503) and 181.3 m (hole 8601), and the deepest seam occurs at 328.1 m (hole 8528). Individual seams are typically uniform in thickness and coal quality. In the Williams Bore area, the typical stratigraphic sequence as drilled comprises of 60-90 m of impermeable Early Cretaceous marine Bulldog Shale, underlain by 60-70 m of water-saturated Cretaceous to Middle Jurassic sands (Cadna-owie Formation and Algebuckina Sandstone), which then unconformably overlie the Mount Toondina Formation which is host to the generally almost flat lying coal measures, showing a westwards dip of only around 1 degree. 72 drillholes had historically been drilled in the vicinity of EL 3326 by Cyprus Australia Coal Company and Getty Australian Coal Company during the period 1984 to 1986. Seven of these holes located in the south-central part of the licence area had been cored, and useful coal quality test data had been obtained from them, while the other 65 were rotary mud holes. The spacing of these holes is irregular: the 7 cored holes are 1.5 km to 5.5 km apart, while the other holes are much further apart. During the first two years of tenure, no work was done by the licensee. During licence Year 3, activities comprised making a detailed review of previous exploration reports and data for the licence area, the generation of a drillhole database, the digitising of pre-existing well log data, and undertaking informed calculations necessary for upgrading the resource status of the Weedina coal deposit to JORC compliancy. An initial Inferred Mineral Resource estimate that was prepared for SAPEX by consultancy group Geos Mining stated that the deposit contains 1.0 Gt of sub-bituminous steaming coal in 6 seams (H to M) in the south-central area, whilst EL 3326 as a whole could contain an exploration target of 2 Gt of similar coal. Of this exploration target, 950 Mt exists in three additional seams, designated N, O and P, at the bottom of the Permian coal-bearing sequence - these seams are less continuous compared to the above inferred resource seams. Because geophysical logs were available for only 22 out of the 92 previously drilled holes, SAPEX had them digitised and then was able to compile representative north-south and east-west cross sections through the deposit to aid in visualisation of the geometry of the coal seams. All of the newly built database on the deposit is appended herein, as is an internal report prepared by SAPEX for a study it made of Arckaringa Basin coal seam gas potential. During licence Year 4, in December 2007, Linc Energy Ltd signed a farm-in agreement with SAPEX and committed to drill 20 closely spaced resource definition holes at the Weedina deposit. The aim of this drilling was to better characterise the upper Mount Toondina Formation coal seams by creating drill coverage at a nominal 1 km hole spacing, thus providing for a more accurate geological model and resource estimate, and also to provide additional information on coal properties and suitability for gasification. Hole locations and the relevant clearances and approvals were obtained. However, the drilling program was subsequently cancelled when Linc Energy merged with SAPEX in October 2008, because of an apparent lack of experienced drilling and logging contractors to undertake the work. This hurdle was illustrated by significant issues which had arisen in the drilling and geophysical logging done nearby on EL 3325 East Wintinna (see Env 11254). A desktop review of the Cyprus Australia / Getty Oil mine feasibility study was undertaken by SAPEX to update the financial model in terms of the expected cost of an equivalent modern day operation, along with the likely increased value of the product, the options now available to transport a product to market, and to identify any additional data that might be required to validate such a plan. From an early stage, it was apparent that the commerciality of the open pit mining proposal still had significant merit, but much risk hinged on the slope stability of the pit and the rate of dewatering in the overlying Cadna-owie and Algebuckina Sandstones. Based on more recent work done in the basin, it was felt that the rate of dewatering had been significantly underestimated and that a detailed hydrogeological study including pumping tests would be required to complete the review, given the effect that this would have on the economics. The study also raised some concerns regarding the original set of rock strength data, which would impact the slope design of any open pit, with a subsequent knock on effect to the economics. During licence Year 5, in a letter sent to PIRSA dated 9/4/2009, Linc Energy advised that the proposed work program for that year would be to revise the exploration plan for EL 3326 and as a priority determine a location for drilling just one cored geotechnical hole in the first quarter of 2010. This drilling would be part of a proposed 8-well campaign spread across several SAPEX tenements in the Arckaringa Basin. The hole would be designed to evaluate the prospectivity of the Mount Toondina Formation coal measures in the north of the licence area, and also assess their engineering geological suitability for being subjected to economical and environmentally acceptable mining practices. In actuality, due to the onset early in December 2009 of extreme weather conditions (storms and flooding), the drilling as scheduled had to be postponed. Working instead at the office, useful historical data such as seismic line and borehole data collected in the 1980s by Cyprus Australia Coal Company and Getty Oil Development Company Ltd were formatted by SAPEX and uploaded into the company's Vulcan 3D mining software package. An Arckaringa Basin geological and lithostratigraphic ‘super model’ was produced, and contour plots of the units' structure, thickness and midburden were created, along with cross-sections, and these were then examined to validate seam names given to coal intersections. The captured data were also intended to be used to help develop a mining feasibility study, where inputs to be gained from the planned geotechnical hole will establish values for important physical parameters which previously were merely assumed. During licence Year 6, the first of replacement EL 4501 issued over the same area as before, no work was done. An aboriginal heritage protection work area clearance survey was performed, and the reconnaissance of field logistics in preparation for planned drilling. During licence Year 7, Linc Energy undertook the drilling in July 2011 of a single vertical rotary mud hole, Crossland Hill 1, to a total depth of 470.6 m, the hole being terminated within the Mount Toondina Formation 50 m below the last coal intercept. The results of this hole enabled correlation between the Weedina and East Wintinna coal deposits, by delineating the full, 23.54 m thick sequence of coal seams in the northern, deepest part of the Weedina deposit, north of the previously drilled resource area. The hole was geologically logged from 1-metre depth interval drill cuttings samples, and was geophysically wireline logged using a density-gamma ray-sonic velocity-resistivity-magnetic deviation tool combination. During licence Year 8, no field work was done. In May 2012, SAPEX engaged Xenith Consulting to complete a full review of all exploration data for the East Wintinna coal deposit for the purpose of calculating an updated JORC Measured and Indicated resource figure for the identified seams. In February 2013, SAPEX engaged Agapito Associates to undertake a geotechnical rock mass Fatal Flaw Analysis for guiding any future instance of underground longwall mining of the deposit. In May 2013, an aboriginal heritage protection work area clearance survey was performed, and the reconnaissance of field logistics in preparation for planned further drilling. During licence Year 9, no work was done. An application to fully surrender EL 4501 was submitted by SAPEX to DMITRE on 3/6/2014.