The Reed Trench vein is a major structure within the Cadillac-Larder Lake-Kirkland Lake break system that hosts the gold mines between Kirkland Lake and Val d'Or. The following combined features indicate that is a structure having high gold potential:

• Another major east-west quartz vein,
• healed fault breccia,
• thin unconsolidated gouge,
• favourable wall rock alteration, and
• the Fe-carbonate that has filled the fractured breccia contains pyrite mineralization

For scale above, the pictured measuring tubes are divided into ten 10 cm increments.

This quartz vein is highly fractured to brecciated. The vein is fully healed by Fe-carbonate that hosts pyrite. A four cm healed fault breccia occurs along one edge of the vein.

Note the contact between the Fe-carbonate altered fault breccia at the top of this photo, and the heavily fractured vein beneath it, with the Fe-carbonate infilling. This is what the sub-crop surface looks like after exposure and cleaning.

This cut sample comes from the Reed Vein, and shows the breccia in detail. The reddish material at the top of this photo is a smooth slip face, and the quartz vein can clearly be seen at the bottom. Separating them is the fault breccia. It consists of angular to well-rounded fragments having different compositions. This suggests fault milling or open-space, fluid-flow milling occurred. This milling process is consistent with structures that may be conduits for ore-forming fluids.