Terra Uranium (ASX: T92) has commenced exploration at the historic Spire and Horizon projects on the eastern rim of Canada’s Athabasca Basin, under an option agreement with ATHA Energy.

The company has mobilised to the site for an initial work program comprising airborne geophysics – including gravity, magnetics and radiometrics surveys – and ground reconnaissance work to follow up on historic mineralised boulder samples.

Exploration will target basement-hosted, near-surface uranium deposits along prominent structural corridors and is expected to be completed within the week.

Option agreement

Terra’s exploration is being conducted in accordance with the terms of an option agreement signed in October with ATHA Energy, which requires Terra to spend $820,000 on Spire and Horizon before the end of December.

A total of five staged exploration expenditures totalling $5.19 million will be required until 2028.

Terra and ATHA will form a joint venture over Spire and Horizon projects after the third expenditure, whereby Terra will hold a 50% participating interest and ATHA will retain a 50% free-carried interest.

Once Terra has met the fourth and fifth expenditures, its equity will increase to 70% and ATHA will retain a 30% participating interest.

Exploration history

Spire and Horizon comprise 12 mineral claims over 610 square kilometres within the Needle Falls Shear Zone (NFSZ), with associated cross-cutting regional-scale Tabbernor faults known for hosting uranium mineralisation.

The projects were first explored in 1963 for zinc and silver, with the last known exploration the reconnaissance work including lake sediment sampling and scintillometer-driven prospecting and soil sampling conducted in 1980 by Marline Oil.

Historic grab samples returned a highlight assay of 2,103 parts per million uranium (0.25% uranium oxide), while the best uranium grades for boulder samples were 6,034ppm (0.71% uranium oxide) and 30,000ppm (3.53% uranium oxide).

Shallow targets

ATHA’s maiden exploration program in 2023 identified approximately 144km of cumulative conductors associated with the NFSZ and regional cross-cutting structures, demonstrating that Spire and Horizon could have a high concentration of shallow targets prospective for uranium and copper mineralisation.

Terra’s new field program has been planned and will be executed by recently-appointed exploration manager Troy Marfleet, who has considerable experience working on greenfield uranium deposits across the Athabasca and Thelon basins.

He will be supported by local Canadian company Axiom Exploration.