The Goderich Salt Mine is located near the east edge of the Michigan salt basin. The stratigraphy consists of a sedimentary rock sequences which includes salt evaporates (or halites) contained within the Silurian-age Salina formation. The Silurian dolomites, shales, and evaporites are overlain by the dolomites and limestones of Devonian-age and underlain by Ordovician limestones and shales. The Salina group is classified into units in ascending order from A to G.

The sediments of the Salina formation approach 3,000 ft (900 m) maximum thickness near the basin depositional center thinning out to several hundred meters or less on the basin margins where the salt is absent. The aggregate thickness of the salt in the Salina formation can exceed 2,000 ft (600 m) in the thickest sequences in the depositional center of the basin, thinning out to zero at the basin margins. The salt strata are highly continuous over the basin, and most of the major salt units can be traced for hundreds of kilometers.

In the Goderich area, the aggregate thickness of the Salina formation is about 1,000 ft (300 m), of which approximately 40% consists of salt beds, with the B unit salt being the dominant salt bed.

The geological interpretation assumes that the A-2 evaporite salt bed is continuous and potentially thickens to the west towards the center of the Michigan basin. The regional stratigraphic sequence is well understood from many wells drilled across the basin and l ........

Salt is mined using the room and pillar method via development mining using continuous miners (each a “CM”) with tungsten carbide teeth shear the salt from the rock face. Production mining is completed using CMs in production panels. Once a panel has been mined, the back is scaled and bolted on a 6’ x 4’ pattern with 7’-6” point anchored mechanical bolts. Continuous miners (CM) are manufactured by Joy Global, a Komatsu company. Once mined, rock salt is loaded immediately onto a flexible conveyor train (“FCT”) that is located at the rear of the CM or by bulldozer (if needed). From the FCT, the rock salt is offloaded to the main underground belt conveyance system where it is then transported to underground crushers and the mill. The general method of mining employed at the Goderich Mine is known as room and pillar mining. In utilizing room and pillar mining, salt is recovered in a horizontal plane, creating a horizontal network of rooms and pillars at multiple stacked levels, analogous to the bays in a parking garage. To do this, "rooms" of salt are extracted via the mining process while "pillars" of untouched material are left to support the overlying roof, also of salt. In salt recovery at Goderich, rooms are mined in multiple lifts or “benches” due to the extensive height of the room. Certain mining units at the Goderich mine are equipped with both a CM and a flexible conveyor train (“FCT”), a dynamic move-up unit and a belt storage unit. On these mining units, the CM cu ........

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