At the Thompson Mine zones of wide and high-grade mineralization are spatially correlated with dilation zones within multiple faulted/drag folded flatter lying stratigraphic sequences within P2. The ore occurs as distinct semi-massive sulphide breccias within these faulted zones as:

* Semi-conformable en echelon and anastamosing sub-vertical vein sets; and
* Flatter lying veins that have infilled dilatant drag folds.

These dilation zones occur at all types of scales, from true widths exceeding 300 feet (100 m) to microscopic scale. Massive sulphide occur locally and less frequently at varying orientations within tension gashes.

Late brittle structures do occur at Thompson Mine but are usually narrow and have limited strike length. Although they can have a negative affect on local ground conditions, they rarely affect the ore zone geometry. The exception is the large brittle 1D fault system that is locally referred to as the Davy’s Fault. It is prevalent within the Pipe formation in the 1D upper and portions of the 1D lower orebodies. In general, the fault crosses the ore zone at a very shallow angle from the south west or in several locations parallels the ore. Depending upon orientation and host rock type the fault can range from a vuggy quartz – carbonate breccia zone up to 100 ft (30 m) across down to graphitic shear zones on scale of a few millimetres. The fault zone affects the local rockmass stability and necessitates use of seve ........

Mine production is sourced from two underground mines: the Birchtree Mine and the Thompson Mine. Mining methods primarily use Vertical Block Mining (VBM), a Slot-Slash Method, with vertical blocks averaging 100 ft in height, and Cut and Fill mining. The ore is crushed underground to -15 cm and shipped to the concentrator.

Since the second half of 2018, Vale has started sending the majority of the nickel concentrate from Thompson to be processed in Sudbury. Since the second half of 2021, Vale has started sending most of the nickel concentrate from Thompson to be processed at the Long Harbour facility, however the material will sometimes be directed to Sudbury, pending the requirements of the operations.