The Turnbull zone is located west of the Jordan River on the Vulcan No.5 and 6 crown grants, approximately 3.2 kilometres north-northeast of the community of Jordan River.

The area is underlain by basalt of the Eocene Metchosin Volcanics and gabbroic and diabase intrusions related to the coeval Sooke Gabbro. The basalt and gabbroic rocks are sheared, brecciated and altered. Granitic intrusions have formed large breccia zones with hornblendite and pegmatites intruding and filling the brecciated older rock.

Mineralization has been exposed by trenching over a distance of approximately 200 metres and consists of chalcopyrite and pyrite hosted by massive basalts.

In 1921, sampling of trenches yielded: 2.14 per cent copper over 1.65 metres from trench C7; 9.02 and 1.65 per cent copper over 0.6 and 1.8 metres, respectively, from trench C6; 2.15 and 2.2 per cent copper over 1.5 and 1.35 metres from trenches C5B and C5, respectively; 0.48 per cent copper over 14.4 metres from trench C4; 0.93 per cent copper over 2.25 metres from trench C3; 0.45 per cent copper over 1.95 metres from trench T6; 0.36 per copper over 4.95 metres from trench T5; 0.84 per cent copper over 2.25 metres from trench T3 and 0.69 per cent copper over 2.1 metres from trench T1 (Hedley Mascot Gold Mines Ltd. [1921-01-01]: Sunro - Surface Development - Gabbro Claims).

In 1926, re-sampling of trenches yielded: 1.2 per cent copper over 1.5 metres from trench C7; to 4.7 per cent copper over 1.65 metres from trench C6; 1.2 per cent copper over 1.8 metres from trench C3; 0.6 per cent copper over 1.26 metres from trench T5 and 1.1 per cent copper over 1.32 metres from trench T1 (Property File - C.C. Starr [1926-06-01]: Map of Cave and Turnbull Zones - Gabbro Mine).

The area has been explored in conjunction with the nearby Sunro (MINFILE 092C 073) past-producing mine since 1915.