Phosphate

The Epenarra Project comprises ten licenses (EL27027, EL26818, EL26775, EL26776, EL27085, ELA27555, EL27554, EL27636, ELA27635 and EL27382) which cover an aggregate area of 5756 km². The Epenarra phosphate project is within close proximity and shares the same geological setting as the Minemakers Wonarah deposit, which is Australia’s largest undeveloped phosphate resource.

Australia’s largest phosphate deposits are confined to the shallow marine Cambrian aged sediments of the Georgina Basin. These deposits include the Phosphate Hill deposit (1400Mt @ 17.5% P₂O₅) in Queensland, which is currently being mined and Wonarah (330Mt @ 18.9% P₂O₅) and Arruwurra (131Mt @ 18.6% P₂O₅) in the Northern Territory (NT), which are currently undergoing pre-feasibility studies. Other deposits in the NT within the same stratigraphic horizon include Highland Plains (56Mt @ 16% P₂O₅), Alexandria (15Mt @ 10% P₂O₅), Alroy (5Mt @ 20% P₂O₅) and Buchannan Dam (8Mt @ 20% P₂O₅).

Interest
Northern Uranium has a 100% interest in the Epenarra Phosphate Project.

Location
The Epenarra project area lies approximately 150 km east and south east of Tennant Creek. Access to the project area is via the Barkly Highway and local pastoral tracks. The project is in reasonable proximity to existing rail and road infrastructure.

The Target
The target is near surface high grade rock phosphate deposits associated with Early to Mid-Cambrian sediments.

Project Geology
The flat-lying phosphatic sediments of the central Georgina Basin are underlain by Precambrian basement and Early Cambrian volcanic rocks. The distribution and relief of the subsurface basement topography has been defined by drilling, magnetic and gravity data, and is believed to the primary control of phosphate deposition in the Central Georgina Basin. The phosphatic sediments and phosphorites of the central Georgina Basin are concentrated and deposited in shallow marine environments along the flanks of the basement highs and are contained within the Mid Cambrian Wonarah Beds and Gum Ridge Formation.  

Exploration Potential
Regional magnetic and gravity data indicates the presence and continuity of Precambrian basement structures, which are considered favourable environments for economic grades of phosphate mineralisation. The Epenarra tenements are along strike and adjacent to the known phosphate deposits in the central Georgina Basin, including Wonarah (330Mt @ 18.9% P₂O₅), Arruwurra (131Mt @ 18.6% P₂O₅), Alexandria (15Mt @ 10% P₂O₅), Alroy (5Mt @ 20% P₂O₅) and Buchannan Dam (8Mt @ 20% P₂O₅) deposits.

Favourable Mid-Cambrian sediments of the Wonarah Formation (which host the well known Wonarah deposit) outcrop and underlie the project area. A desktop review of historical exploration has shown the tenements to be relatively untested for phosphate mineralisation.

Work Program
Improved quality NT Government airborne geophysical data (specifically gravity data) over the central Georgina Basin become available in 2009. The new data provides greater detail of depth to basement and assists in identifying potential shallow marine environments which are favourable for hosting phosphorite deposits.

• Reprocessing of central Georgina Basin gravity raw data to generate new geophysical images
• Geological reconnaissance and sampling to follow up several outcrops mapped in the area as Wonarah Formation
• Generate drill targets based on the geophysical interpretation and geological site inspections
• Wide spaced RAB or Aircore drilling of target areas