Three adjacent areas located in dissected hilly country 70-90 km to the north-west of Oodnadatta were successsively taken up under licence to cover a significant, 8 mGal regional gravity anomaly which could have potential for IOCG type basement-hosted mineralisation. Prior to the involvement of Macallum Group Ltd (MGL) through its owner, grant licensee Christopher Reindler, minimal exploration work had been done on this anomaly, with no drilling into basement; but there had been several phases of regional and local geophysical surveying, including magnetic, radiometric and gravity. These surveys had defined a large dimensioned gravity anomaly near Mount Sarah, with an offset magnetic high. The source of the gravity anomaly was thought to be located ~500 m below the surface. The magnetic high had been defined by regional airborne magnetic and radiometric surveys flown between 1992 and 1994, and its source was thought to be located at about 1500 m below the surface. During the initial year of tenure (of EL 5634 Mount Sarah on its own), licence operator MGL performed a comprehensive literature review of all available public domain geoscientific information previously acquired around the tenement and in the surrounding region, and also acquired a detailed ground gravity survey in November 2015. The survey was designed to define features of the ~5.5 km x 3.5 km extent Mount Sarah gravity high that had been mapped in 2007. A total of 509 new stations were read along east-west lines 400 m apart, using 200m and 100 m station intervals. This coverage resolved that there are two distinct peaks to the anomaly. It also provided a better estimate of the density of geological units which make up the surface topography at Mount Sarah (Mount Sarah Sandstone and Oodnadatta Formation). Once Bouguer and terrain corrections using a density of 1.9 tonnes per cubic metre were applied, the modified gravity profile response became smooth, consistent with a deep compact source, or a shallower, laterally extensive source. During Year 2 of the project, still working just on EL 5634, preparations were made to drill near the eastern peak of the Mount Sarah gravity anomaly. An Aboriginal heritage protection work area clearance survey was conducted in October 2016 with representatives of the Walka Wani Aboriginal Corp. RNTBC, which cleared seven potential drill sites. To assist with funding the first drillhole of this undertaking, a PACE Discovery Drilling Program 2016 Project Proposal Form was completed and lodged with the DSD for appraisal, during April 2016. The drilling project subsidy funding was approved in writing by DSD in August 2016, to the level of $75,000, as PACE Project DPY9-05. This agreement covered the planned drilling of hole MS004, that was programmed as an ~500 m long rotary mud precollar through Great Artesian Basin sediments, and then a 300 m long HQ diamond cored tail within Proterozoic basement rocks, which were expected to be granitic equivalents of the Peake Metamorphics and Wirriecurrie Granite similar to what had been encountered by past drilling done at Mount Carulinia closer to Oodnadatta. During Year 3 of the project, hole MS004 was drilled vertically to a total depth of 811.3 m in July 2017. At a depth of 461 m it encountered Neoproterozoic basement rocks which consisted of variably brecciated and variably haematite-chlorite-sericite-carbonate altered metasedimentary units that continued through to TD. Some anomalous geochemistry was detected within the breccias, featuring sulphur, selenium and tellurium plus the gold pathfinder elements antimony, arsenic and bismuth [for a full discussion of the drillhole data, see PACE Year 9 collaborative drilling project DPY9-05 final report, held separately in Env 13064]. Because there appeared to be an insufficient density contrast between the breccia and the cover rocks to account for the ~26 square km Mount Sarah gravity feature, MGL decided to acquire passive seismic (PS) and magnetotelluric (MT) ground geophysical surveys over the prospect that were aimed at more widely defining the depth to basement below the Great Artesian Basin sediments and at looking for one or more MT conductors within the basement that could represent sulphides associated with an IOCG or other style of mineral system. The PS survey which was conducted in November 2017 on an 10 km x 14 km grid did help to define the depth to the cover-basement unconformity, which has a first order similarity to the shape of the Mount Sarah gravity anomaly as well as the dominant surface topographical features, and a conductor was detected by the MT survey of 106 stations performed in December 2017-January 2018 on the same grid, which coincides with the western peak of the large and unaccounted-for gravity high. Therefore plans were made to drill at least one more vertical, 1500 m deep exploratory hole to target this MT conductor and coincident gravity high, which it was interpreted could represent a large, strongly altered and sulphide-mineralised breccia pipe. Two additional Project licences EL 6018 and 6129 were granted to MGL in September 2017 and March 2018 respectively, increasing by four times the area of ground it held across the G2 lineament swath in the Mount Sarah vicinity. During Year 4 of the project, activities occurred predominantly on EL 5634, where new work included the drilling of 2 vertical exploratory holes, MS005 (abandoned at 323 m) and MS006 (TD 1209.1 m). This drilling targeted both the western peak of the Mount Sarah twin peak gravity high and a coincident MT conductor, with the aim of testing these features for disclosing a possible iron oxide - associated copper-gold (IOCG) mineralised system. MS005 was abandoned within cover sediments of the Great Artesian Basin (GAB) due to encountering difficult drilling conditions. MS006 was collared 9 m away to the north of MS005, and was rotary mud precollared to 313 m depth before the hole was cased and pressure cemented off. Once it had penetrated beyond that point by diamond coring to beneath the base of the sediments of the GAB at 475 m, MS006 entered a thick sequence of fine-grained, variably laminated pyritic black shales and siltstones believed to be of Neoproterozoic to Cambrian age, with a likely correlation to the Warburton Basin. Downhole geophysical logging and subsequent interpretation indicated that the black pyritic shale accounts for the targeted western gravity high and MT conductor. No anomalous downhole sample assay geochemistry or XRF spectrometric scanning results were detected within the shale, and no signs of an IOCG type system were seen in the drill core. In early 2019, as part of a wider project addressing 11 of the company's tenements in South Australia, available aeromagnetic survey data for the subject licences were reprocessed for Copper Search Australia Pty Ltd (CSA) by South Australian geophysical consultancy Archimedes. Firstly, a 3D model of magnetic point data was generated across the project area which was carried down to a depth of around 4 km. This model of magnetic susceptibilities was then viewed as a series of vertical slices in various orientations, and zones of high to very high magnetic susceptibility were defined as polygons. Importantly, several approximately vertical pseudo-structures that may be indicative of IOCG style breccia pipes were identified from the review of these data. During Year 5 of the project, work was confined largely to the commissioning by CSA of a review carried out by research personnel from CSIRO of geophysical, geological and geochemical data that had been generated by the drilling and surveys done at Mount Sarah between 2015 and 2018. The main areas that were studied by personnel from CSIRO were: - A re-interpretation, constrained by wireline petrophysical measurements, of the geophysical data models, particularly the MT and gravity inversions that had shown discrete, coincident anomalies that had been targeted by drillhole MS006 in 2018. - A geochemical analysis of the shale that had comprised a very thick package in MS006 below the Eromanga Basin cover. - A review of passive seismic, DEM, radiometric and drilling data over the project in an attempt at modelling cover thickness and the location of possible faults. The conclusions arrived at were: - That the geophysical survey results were consistent with the conductive, dense carbonaceous shale that was found beneath the Eromanga Basin sediments in MS006. - Physically, temporally, chemically and electrically the black shale in MS006 shows many similarities to the Neoproterozoic Pertatataka Formation that is found in the Amadeus Basin in the Northern Territory. This may indicate that parts of the Officer Basin underlie the Eromanga Basin / GAB sediments. The Officer and Amadeus Basins once formed part of the Centralian Superbasin that covered a large part of central Australia. - Possible faults identified at the surface were inferred from radiometric and DEM data. These features may be surface expressions of deeper structures that go through to the basement, and could provide a focus for exploration activities in the future. - A cover thickness model was produced that included inputs from downhole sample geology logs, wireline geophysical logs, and passive seismic survey data. The inferred faults identified in the analysis of DEM and radiometric data were also incorporated into the final model. The results of this Bayesian modelling were presented as graphical examples of what could be done with a set of data. No actual digital DEM surface was delivered. In March 2020, CSA allowed tenure of EL 6129 Todmorden to lapse at expiry of its second year. The lack of mineralisation or significant alteration in pre-Mesozoic drillhole samples from MS004 and MS006, together with the conclusions of their K-Ar age dating and the CSIRO review, all led to CSA deciding to cease exploration on EL 5634 Mount Sarah and not to seek a renewal of that licence for a second five-year term after 22/6/2020.