The Southgate Blacksand is found on the Southgate River Estuary. The Southgate River flows into the east side of the harbour at the head of Bute Inlet.

The prospect is located on the flat flood plain area near the mouth of the river. Unconsolidated sand occurs throughout the area, in places more than 15.24 metres thick. The sand is composed of white quartz grains, magnetite grains, clay, brown biotite flakes and minor feldspar and epidote grains.

A best assay of 66.4 per cent iron and 0.59 per cent titanium was obtained from a sand sample containing 10.21 per cent magnetite by volume. For an area 1372 by 1219 metres and to an average depth of 16.76 metres, the potential is for 2,222,603 tonnes of magnetite (Property File - Cooke, D.L., 1972).