The Hel area is underlain by Upper Cretaceous to Paleocene coarse clastic sediments consisting of chert-grain sandstone, conglomerate and minor shale. These are overlain by trachytic and rhyolitic flows and pyroclastic rocks of the Early Eocene Sloko Group. To the east are Upper Triassic Stuhini Group volcanci rocks and to the south are Lower Jurassic to Middle Jurassic Hazelton Group volcanic rocks.

Uranium occurs as saleeite and torbernite within the upper conglomerate unit, over several metres along strike in a zone up to 30 centimetres thick. Mineralization is also associated with inter-layered oxidized sandy layers and organic material. A trench sample assayed 0.397 per cent uranium (Assessment Report 7708). A bulk sample over a 2 metre strike length and 20 centimetre thickness assayed 0.0843 per cent uranium (Geological Survey of Canada Paper 82-1A).

The uranium was likely derived from overlying felsic volcanics transported by means of downward percolating groundwaters, and fixed by organically dominated material.