Summary:
Atlas Geology
The Atlas resource is a continuous body of mineralisation approximately 15km long and up to 150m wide with an average thickness of 6m. The southem 12km is planned to be mined with HM grade decreasing to the north.
The sedimentary package that hosts both the Atlas and Campaspe deposits is typical of most other mineral sands deposits in the Murray Basin, comprising:
• Woorinen Formation (recent dunes);
• Shepparton Formation (terrigenous fluvio-lacustrine deposits); and
• Loxton Parilla Sand (littoral marine sediment) hosting the mineralisation.
A consistent high-grade domain, denoted Domain 1, occurs along the length of the deposit which is typically less than 100m wide. The deposit is overlain on average by 26m of overburden which consists of a thin 1-3 m layer of the Woorinen sandy clay Formation and approximately 20m of Shepparton Formation, which consists of sandy clays and minor sand beds with mildly indurated zones.
Geological interpretation splits the high-grade Domain 1, which is defined by a 5% HM grade cut-off, into two sub-domains, 1A and 18. Domain 1A has an average HM grade of 25.2%, with 17.2% rutile and 11.4% zircon in the HM. Domain 18 typically lies below and to the east of Domain 1A, has an average HM grade of 14.0% and contains 14.6% rutile and 7.7% zircon in the HM. Domain 2 is a lower grade envelope defined by a 1% HM grade cut-off.
The orebody dips 39m over 10km, before being faulted up near the northern extent of the ore reserve.
Campaspe Geology
The Campaspe mineralisation is over 20km long and averages 420m wide, defined by 1% HM grade cut-off. The mineralisation averages 12m in thickness. The deposit is shallowest at the south-eastern end, averaging less than 10m of overburden, but deepens to the north with an average overburden depth of 25m. The current plan is to restrict mining to the southem 13.5km of the deposit, up to the fault position at 21500mN. North of this position the mineralisation deepens significantly.
The resource estimate is in part Measured (100m and 200m spaced drilling) and Indicated (400m spaced drilling) south of the 21500mN fault position, and all Inferred (800m spaced drilling) north of that position, none of which is considered in the current lifeof mine plans.
The overburden consists of a 1m to 6m layer of the Woorinen Formation, consisting of clayey, poorly sorted sands, and an averageof 20m of the Shepparton formation consisting of interbedded clays, sands and silts. The thickness of the overburden increases northwards. The Loxton Parilla Sand, hosting the mineralisation, is a fine-to mediumgrained, very well sorted beach sand that averages only 2% clay.
The mineralised domains across the deposit are quite variable and represent past beaches and dunes. Domain 1, located on the westem side, is the highest-grade beach. Domain 1 is approximately 60m wide and 6m thick, with an average grade of 12.4% HM containing 11.4% rutile and 14,6% zircon. Domains 1 to 4 are broadly based on a 5% HM grade cut-off, whereas Domain 5 is a higher-grade dune with a 3% HM grade cut-off. These high-grade domains can be traced along the length of the deposit. Domain 6is the halo of low-grade mineralization defined by a 1% HM grade cut-off.
The deposit is at surface at the southern end and is predominantly above the water table. The deposit dips northward with the baseof deposit dipping below the water table.
The most obvious post-depositional structural modification is a significant down-throw of the stratigraphy and mineralisation by approximately 30m at 21500mN. The current mine plan ends at this northem down-throw.