The Union Hill Mine lies within the northern extremity of the Central Maldon Shear Zone, located within the central part of the Bendigo Zone of the Lachlan Fold Belt.

The stratigraphy is composed of substantial volumes of strongly and complexly deformed (folded and faulted), thick-bedded turbidites of the Ordovician Castlemaine Group which have undergone metamorphism to lower greenschist facies and have been intruded by Devonian granites, producing contact metamorphic aureoles up to a few hundred metres wide.

The host rocks consist of Ordovician (Lancefieldian) turbiditic metasediments of the Castlemaine Group (490-450 million years, Cas and VandenBerg, 1988) which have undergone several major deformational events, reflecting a regional thin skinned style tectonic history. The dominant regional structures are tight, isoclinal, north-south trending asymmetric F2 folds with a pervasive axial planar cleavage and occasional small parasitic folds. Regional greenschist facies metamorphism was contemporaneous with F2 folding.

Maldon Project The Maldon Gold Operation is centred around the town of Maldon and consists of exploration and mining licences overlying the historic Maldon, Wehla, Amherst and Dunolly Goldfields.

Centennial mining licence MIN5146 contains the Union Hill Mine and overlies the Maldon town site and most of the main producing reefs of the Maldon Goldfield, which between 1856 and 1926 produced over 1.7 million ounces of gold.

The metasedimentary sequence and reef systemswere intruded by the Late Devonian sub volcanic Harcourt Batholith, which comprised at least three separate, dominantly granodiorite intrusive phases.

Quartz porphyry, diorite and basaltic lamprophyre dykes also intrude the Ordovician sequence. A quartz porphyry dyke appears to have intruded at east one of the major reef systems at Maldon. Evidence of post-granitic deformation includes reverse and strike-slip faulting, some of which is associated with the intrusion of an ultramafic dyke.

Orogenic Gold deposits in the Western Lachlan Fold Belt, including the Bendigo Zone, which hosts the Maldon Goldfield and MIN5528, typically occur in quartz vein systems occupying brittle ductile structures concentrated in regional anticlinoria. The distribution of some gold deposits is also thought to be controlled by deep first order faults.

Development of the main Decline from approximately the 1080 level commenced at the Union Hill Mine mid-way through the June Quarter after several weeks delay waiting for the necessary approvals to recommission the underground explosives magazine.

The run-of-mine trucked to the Porcupine Flat Processing Facility to date is from where the Alliance South Shoot was intersected at right angles by the 1060 Level waste cross cut from the Decline.

Typically, the mineralisation is between 1m and 3.5m in width. Strike driving on the 1060 Level will enable the higher grade areas of the shoot to be identified and selectively mined using narrow long hole stopes.

Centennial completed review of historical data and from that review was able to plan the re-opening of Union Hill Mine, as a trial, to potentially add a second ore source for the Porcupine Flat Mill.

- 130,000 - 150,000 tpa CIP gold processing facility with additional crushing capacity.
- Permitted and Operational:
- Generally operating to expectations;
- Adding crushing capacity to achieve +160ktpa.
- Additional 3 year tailings capacity already permitted.
- Fresh water supply from mine.
- State Grid Power.
- Main Road Access.
- Viable cartage distance to all of Centennials deposits.