Uranium occurs in a variety of deposit types. It is present in all rocks in small amounts, but is present in elevated background amounts in rocks such as granites. Rocks with high background uranium content usually provide the ultimate source of uranium that is then concentrated by physical or chemical processes into the various styles of uranium deposits. These can range from particular phases of granites, such as at the Company's Kalabity and Charley Creek projects, to near surface precipitates of secondary uranium minerals like carnotite, in limestone-filled desert drainage channels (calcrete deposits), as may occur beneath the Charley Creek plains.
The Crossland management and technical team is particularly experienced in what are now known as Unconformity-Related Uranium Deposits (URD), particularly in the style that occurs in northern Australia. The URD are a particularly important style of deposit:
- URD have provided most of Australia's uranium production, commencing with Rum Jungle in 1953, extending to the present with the Ranger Mine, currently the nation's largest producer.
- URD also provide all of Canada's current production, and the largest portion of the world's production.
- URD often contain grades of several kilograms of uranium per tonne, or even percentage values. The Cigar Lake and McArthur River deposits in the Athabasca Basin of northern Saskatchewan have average grades exceeding 20% U3O8.
- The higher grades are sometimes enough to enable small tonnage deposits to be worked profitably, for example those in the South Alligator Valley in the Northern Territory.
Crossland believes that the spectrum of grades and tonnages that characterise URD represent more realistic targets for near-term development by junior explorers than some other deposit styles. The URD type of deposit is the target at Crossland's Chilling project.
Crossland sees the possibility that the Chilling project area is the western mirror image of the Alligator Rivers Uranium Field (ARUF) which contains deposits such as Jabiluka, Ranger, and Koongarra on the east side of the Pine Creek Orogen. Crossland's holdings in the Chilling project cover a similar geological setting and are large enough to include the entire Jabiluka-Ranger-Koongarra corridor that has production and reserves that exceed 300,000 tonnes of U3O8.
In Crossland's view, there are three essential ingredients for formation of uranium deposits. These are:
- A suitable source of uranium
- A suitable mechanism to transport it
- A suitable site for deposition
These ingredients are essential for all types of uranium deposits, and the specific criteria differ between deposit styles