The geomorphic feature known as the Ooldea Range, a prominent Eocene dune formed at the limit of the marine transgression on the eastern margin of the Eucla Basin, has now been taken under licence by WA-based company Iluka Resources to explore for possible buried economic occurrences of zircon-rich heavy mineral sands (HMS) that may have been formed along palaeo-beach and shoreface strandlines during the five marine incursions that occurred from the Middle Eocene to the Pliocene. The Ooldea Range flanks the Nullarbor Plain in SA, and is elevated 40 m to 150 m above adjacent terrain. It varies in width from 10 km to 20 km. Within the body of the range, winnowed sandy sediment horizons of the Hampton Sandstone and Ooldea Formation are the target host strata for mineral sands deposits. Work undertaken by previous explorers between the mid-1980s and early 1990s addressed these targets, but with only limited drilling success, when National Mineral Sands were able to outline a small resource named the Immarna deposit, that contains two zones of HMS mineralisation that were thought to represent two different ages of deposition. Tenure here was later allowed to expire due to perceived factors of the depth of overburden, lack of concentrated mineralisation, and low rutile content in the sampled HMS. All of the subject licence lies within the Yellabinna Regional Reserve, which is 2.5 million ha of bushland representing a remnant 17% of the total South Australian Mallee vegetation cover that existed at the time of colonial settlement. Yellabinna’s remoteness and almost pristine condition give it very high wilderness value. During the first licence year, Iluka made a reconnaissance visit to the Ooldea region to collect surface samples of heavy minerals and to explore access for future drilling. 3 soil grab samples were collected and analysed in Iluka's Geraldton laboratory. The heavy mineral concentrate initially obtained from these soil samples by the desliming, dissolution and sieving process routinely used for cleaning drillhole samples in Iluka's Narngulu laboratory was next separated into magnetic and non-magnetic grain fractions, which were then further separated by heavy liquid media into 9 specific gravity range fractions. Lastly, XRF spectrochemical assaying was conducted on each fraction. It was found that the HMS mineral assemblages are low in trash species but high in zircon and altered ilmenite. Mineragraphic examination of the magnetic trash grains showed a high proportion of leucoxene. This observation was confirmed by high Ti02 in the XRF analysis. Geophysical data processing contractors Pitt Research were commissioned to perform a depth to magnetic basement study, which gave promising results. Using this study Iluka were able to compile an interpreted basement topographic map which clearly showed evidence of buried old coastlines. A review made of the processed aeromagnetic survey data revealed some 1-2 nT linear anomalies located near to the old coastlines that it was inferred could be strands, and they remain untested. These anomalies appeared only in areas of magnetically quiet basement, such as the northern portion of the Ooldea tenement. Pitt Research used regolith filters to look for similar magnetic anomalies in higher magnetic response areas in the south, using Iluka's basement topography map as a guide, but no anomalies of note were evident. Iluka decided that on EL 2900 there were several magnetic anomalies worthy of drill testing in the vicinity of the company's modelled target elevation of 130-160 m. A Declaration of Environmental Factors was prepared and submitted to PIRSA and DEH, which proposed a 5000 m exploratory drilling programme to be undertaken during 2003. During licence Year 2, the commencement of drilling was delayed for two main reasons, viz. the SA Government's late approval of Iluka's DEF (December 2003), and the delay in grant of some nearby tenements also located within the Yellabinna Regional Reserve (because the subject EL 2900 was just a small part of a much larger exploration play sought by Iluka in the Eucla Basin). Iluka's logical and preferred plan was to drill these other tenements concurrently. Consequently, no work was done on Ooldea for this year. During licence Year 3, a regional HMS exploration drilling program was conducted between September and November 2004, when 245 vertical aircore/RC NQ open holes were drilled along five traverses spaced 2.5 km apart which were located partly within the EL 2900 area, for a total penetration there of 9375.5 m. The traverses were aligned in a NE-SW direction across the Ooldea Range. Drillholes were collared at 400 m intervals along the traverses, with infill holes positioned to define any mineralisation. Sampling of the holes occurred at 1.5 m depth intervals, with a representative 1 to 1.5 kg split of the recovered drill cuttings taken by rotary splitter to submit for laboratory heavy mineral analysis. All samples were panned and were lithologically logged on site by a geologist. The ease with which clays were liberated from a sample was logged on a scale of very easy to impossible, and the percentage of clay (“slimes”) was also recorded. The presence and type of cemented fragments (“rock”) was recorded, with an estimate of percentage. The ease with which the drill bit penetrated the ground was recorded on a scale of 1 to 5 (“hardness”). Sediment colour, dominant grain size, max grain size and degree of sorting were also recorded. All hole collar positions were surveyed by GPS. The drilling proved to be successful, giving confirmation of the existence of well developed Eocene beach sand sequences along the western edge of the Ooldea Range, and within this stratigraphic setting, making the discovery, just 3 weeks after the start of drilling, of two zircon-rich HMS placer strand deposits, called “Jacinth” and “Ambrosia” by the licensee. To facilitate prompt evaluation of these deposits via proposed delineation drilling, a second DEF was compiled and approved for EL 2900 that would allow Iluka to conduct grid-based drilling to 200 m line spacing, and to construct a field accommodation camp at Jacinth accessed by a new track built to link with the Yalata to Ooldea Siding road. 1908 prepared drill cuttings samples were assayed for their HM content at Iluka’s laboratory in Hamilton, Victoria. These samples were dried, weighed, and attritioned, then wet screened to remove the slime (-53 microns) fraction. The samples were again dried, weighed, and screened to remove the fraction greater than 2 mm (oversize), and an approximate 100 g homogenous sub-sample was obtained for assay. The samples were further screened at 710 microns and the remaining sub-sample of the -710um +53 um fraction underwent HM separation using LST (a solution of lithium poly tungstates) at a specific gravity of 2.85. The weights of the separates were then used to calculate percent slimes, percent oversize and percent HM for the entire sample. Backup samples of the oversize and sand fraction plus the separated HM fractions have been retained to allow further analysis. As part of the 2004 drilling programme on EL 2900, samples of frequently occurring calcrete were assayed for gold, but no anomalous values were returned. The two newfound deposits, Jacinth and Ambrosia, lie at the base of the western side of the Ooldea Range, within a 'J'-shaped palaeoshoreline bay feature. Jacinth is arcuate in plan, probably due to the bay shaped morphology of the basement. Both deposits lie on top of granite or sandstone basement rocks, and appear to have formed in bay-like traps that were separated by headlands located along the ancient shoreline. The sandstone basement has altered to hard purple ironstone, which may be either a cemented base of the original strand, or an older sandstone unit separated by an unconformity. The deposits have classic HM beach placer morphology, including a high grade strand at the base overlain by lower grade dunal sand. Jacinth outcrops for up to one third of its length. Where it does not outcrop it is covered by barren Ooldea dunal sand, which in turn is overlain by up to 2 m of calcareous Quaternary sands. As of end November 2004, Jacinth and Ambrosia had been drilled at a nominal 1 km infill traverse spacing, with holes placed every 50 to 100 m. This hole coverage indicated that the Jacinth deposit has an approximate size of 4.5 km in length and a width of 500 m to 1 km. The footprint of Ambrosia is somewhat smaller than that for Jacinth, it having a length of ~4 km and a width of 200 m to 1 km. Both deposits contain a valuable HM assemblage that on average consists of 55% zircon and 7% rutile, plus between 14 and 22% ilmenite. The sand average slimes content is 11.2%. Preliminary, JORC Code - compliant Inferred Resource figures were calculated by Iluka for each deposit, based on a HM cutoff of 1%. It was estimated that Jacinth contains 108 Mt of material grading an average 6% HM, for 6.5 Mt of HM, while Ambrosia contains 54 Mt of material grading an average 3% HM, for 1.6 Mt of HM : the combined total resource thus being 162 Mt with 8.1 Mt of contained HM. During licence Year 4, Iluka performed HM resource delineation drilling along traverses spaced 400 m apart, later stepping down to a 200 m x 50 m grid spacing, at the Jacinth and Ambrosia deposits, as well as 1.5 km x 400 m sterilisation drilling of the adjacent areas. A total of 1519 BQ aircore/RC open holes for 46,937 m were completed over three campaigns. In addition, a number of field data-gathering components of a mining pre-feasibility study were undertaken by specialist contractors. No regional exploration was done. The additional deposit drilling data obtained for Jacinth informed the calculation of an initial Indicated Resource of 114.7 Mt of material grading an average 5.3% HM, for 6.129 Mt of HM, using a 1% HM cut-off grade. Sinclair Knight Merz engineers were commissioned by Iluka to oversee an evaluation of the means and economics of mining the two deposits, and to undertake environmental risk management research, initially through performing baseline environmental surveys of flora, vegetation, fauna, pedology and hydrogeology. As part of the groundwater assessment, several water bores were drilled to source water for the primary purpose of road construction and maintenance. A total of 3 vertical rotary mud holes for 520 m were drilled in August 2005 by Underdale Drilling. Of the three bores, one collapsed during drilling and was abandoned, one hole was dry, and the other was completed and is supplying water at the rate of approximately 0.75 litres/second to a turkeys nest dam built adjacent to the bore. A groundwater sample taken from this hole was dispatched to Amdel for full water analysis. Also, 125 composite samples of the drill cuttings were submitted for multi-element analysis. During licence Year 5, regional exploratory drilling was resumed on EL 2900, with 133 holes for 6004 m completed. The drillholes located to the north of the Jacinth and Ambrosia deposits in general did not reveal any notable HM occurrences. Only a single hole, YE1127 on line 48750N, encountered a significant mineralised intercept of 11.3% HM. However, from drilling located to the south-east of Jacinth, an interpreted aeolian sediment-hosted HMS prospect ("Typhoon") was discovered. This prospect has an apparent length of 800 m and is up to 13 m thick, and contains mineralised horizons carrying up to 10% HM (2.7% average). Holes YE1284, YE1285 and YE1287 located on the same traverse had intercepts of >1% HM over intervals of >4 m, with grades ranging between 1% and 7% HM. Resource delineation drilling at Jacinth and Ambrosia was completed during the year, with a further 206 holes for 6554.5 m drilled, again on a 200 m x 50 m grid spacing. Iluka undertook an evaluation of certain low cost geophysical surveying methods such as ground penetrating radar, microgravity, and airborne electro-magnetic (Hoist-EM) for their utility as HM occurrence targeting tools, but the results were inconclusive. The trial Hoist-EM survey was conducted in December 2005 along east-west flight lines spaced 2 km apart, by contractor GPX Airborne. The microgravity survey was run during November-December 2006, when 933 detail gravity stations were read by contractor Haines Surveys on three irregular grids designated as RAB lines (5 of), Jacinth (3 lines) and Ambrosia (2 lines). During licence Year 6, under tenure of renewed Ooldea Range EL 3742, Iluka continued work on the prefeasibility study for the proposed Jacinth mine, for which more than $12M had already been spent during 2006. As part of the study, Iluka undertook sterilisation drilling around and near the proposed sites of mine infrastructure, a necessary process in order to avoid building infrastructure over areas of mineralisation. Further holes were also drilled at Jacinth and Ambrosia for orebody edge definition. A combined total of 223 new vertical aircore/RC holes were drilled during June-July 2007 to satisfy these aspects. Other drilling (18 shallow aircore/RC holes) was undertaken in November 2007 for the purpose of locating suitable extractive materials that could be excavated via borrow pits to use for road building. Ongoing environmental impact assessments that were made for the prefeasibility study during 2007 included the conduct by consultant experts of threatened species, vegetation, indigenous heritage, air quality, noise abatement, surface hydrology, borefield aquifer geology, soil type mapping and open pit mine design excavation geotechnical engineering surveys. For regional HM exploration within EL 3742, a minor amount of target drilling (17 vertical aircore/RC open holes for 559.5 m) was conducted to the south of Jacinth and Ambrosia to investigate a possible basement headland/re-entrant HM trap. Several low grade HM intercepts were made, the highest being 9 m @ 1.7% HM in hole YE1609. During October 2007, surface soil sampling was undertaken over the Typhoon prospect, where 54 grab samples were collected for heavy mineral analysis. Grades for these samples ranged from 0.4% to 3.9% HM. During licence Year 7, additional sterilisation drilling of 9 vertical aircore/RC holes for 343 m was performed over the Jacinth and Ambrosia deposits, where the Measured Resource estimates currently stand at 111 Mt @ 5.5% HM and 86 Mt @3.0% HM respectively. Importantly, over the period March to June 2008, the mining feasibility study for the Jacinth and Ambrosia deposits was completed, and was submitted to the Iluka board of directors for approval. It was rapidly approved, and consequently activities at Jacinth and Ambrosia were advanced into the early stages of mine development. In July 2008, a mining lease (ML 6315) was granted to Iluka covering both Jacinth and Ambrosia. Mine production has been forecast to commence in 2010. Resource delineation drilling of 85 vertical aircore/RC holes for 4357.3 m was undertaken on the Typhoon prospect over the period August to November 2008, with the aim of developing an Inferred Resource estimate. During July-August 2008, some further regional HM exploratory traverse drilling (39 vertical aircore/RC open holes for 1849 m) was conducted near Ambrosia with 400 m hole spacing, to follow up a possible HM anomaly.