Exploration & Mining Glossary

Sericite - Is an alteration mineral of micas (generally formed of muscovite or paragonite). It is formed by the hydrothermal alteration of orthoclase or plagioclase feldspars. Sericite alteration is closely associated with pyrite alteration, and they're a common alteration to halo the chalcopyrite and pyrite stockwork/stringer veins in the footwall which feed the (possible) massive sulphide lenses.

Shear-hosted - Shearing is the deformation of brittle-ductile or ductile rocks (the deformation of brittle rocks usually results in faulting) caused by compressive stress. Areas of rock which have undergone significant shearing may be refered to as 'shear zones'. Shear zones may host mineralisation, as hydrothermal fluids will use this deformation as conduits to flow through; forming 'shear-hosted' mineralisation.

Silicification - The accumulation or replacement by silica such as fine grained quartz, chalcedony, or opal, which can replace existing minerals or fill pore spaces.

Siltstone - Is a fine-grained clastic sedimentary rock. It is typically composed of predominately silt sized grains and formed in low energy marine/fluvial/lacustrine/glacial environements. Within Peel Mining's projects, siltstones are commonly seen within turbidite sequences (a marine environment).

Silver (Ag) - Is a precious metal which generally occurs within Galena, where it substitutes for the lead in the mineral's atomic structure. Is is a soft, white, lustrous metal, which exhibits the highest electrical conductivity, thermal conductivity and reflectivity of any metal.

Sphalerite - A mineral that is the chief ore of zinc. It consists largely of zinc sulphide in crystalline form but almost always contains variable iron. When iron content is high it is an opaque black variety, marmatite. It is usually found in association with galena, pyrite, and other sulphides along with calcite, dolomite, and fluorite. Miners have also been known to refer to sphalerite as zinc blende, black-jack, and ruby jack.

Stoping - The process of extracting the desired ore or other mineral from an underground mine, leaving behind an open space known as a stope. Stoping is used when the country rock is sufficiently strong not to collapse into the stope, although in most cases artificial support is also provided.

Strike - The direction of the line that is formed by the intersection of the plane of the rock bed with a horizontal surface. Strike indicates the attitude or position of linear structural features such as faults, beds, joints, and folds.

Stringer - A stringer lode is one in which the rock is so permeated by small veinlets that rather than mining the veins, the entire mass of ore and the enveined country rock is mined. It is so named because of the irregular branching of the veins into many anastomosing stringers, so that the ore is not separable from the country rock.

Structurally controlled - A geological structure is the three-dimensional distribution of rock units with respect to their deformational past, these include; faults, shears, breccias etc. Structurally controlled refers to the mineralisation taking advantage of these structures, either as a conduit or space to accumulate in (see shear hosted).