RE: Molopo Farms Update2 Apr 2021 13:50
In plain English Corby I believe it means there is no Nickel Sulphide present in the third hole
Earlier for the third hole KKME reported that "Coring started from 15.8m. The rock intersected is an apparently monotonous ultramafic, probably a serpentinised dunite. It is much less fractured than the rock in the first two holes. No pyroxenite or obvious harzburgite was seen. The rock is fresh from about 91m."
Serpentinization is a processes whereby rock (usually ultramafic) is changed, with the addition of water into the crystal structure of the minerals found within the rock. A common example is the serpentinization of peridotite (or dunite) into serpentinite (the metamorphic equivalent).
Metamorphic processes usually involve the addition of heat and pressure: a rock is buried, heats up and is squeezed, and the minerals change in an attempt to regain equilibrium with the new environment (like shale to slate, or limestone to marble).
In the case of peridotite to serpentinite, the process actually involves a reduction in heat and pressure. Peridotite starts out as a sub-crustal, upper mantle rock. If tectonic forces move it nearer to the surface, the reduction in T&P cause the minerals (usually olivine and pyroxene) to destabilize and change into the mineral serpentine. No, I'm not mixing up rocks and minerals. Serpentinite is a rock which is composed of the mineral serpentine and formed by a process called serpentinization
The pyroxenes (commonly abbreviated to Px) are a group of important rock-forming inosilicate minerals found in many igneous and metamorphic rocks. Pyroxenes have the general formula XY(Si,Al)2O6, where X represents calcium, sodium, iron (II) or magnesium and more rarely zinc, manganese or lithium, and Y represents ions of smaller size, such as chromium, aluminium, iron (III), magnesium, cobalt, manganese, scandium, titanium, vanadium or even iron (II).