Remobilization, syn-tectonic processes and massive sulphide deposits

The hydrothermal system of Central Jebilet (Variscan Belt, Morocco): A genetic association between bimodal plutonism and massive sulphide deposits?

“…'Chalcopyrite disease' (Wiggins and Craig, 1980;Barton and Bethke, 1987) is generally present in sphalerite. (b) Brittle behaviour is displayed by pyrite and arsenopyrite that constitute the high strength minerals in the deposits (Graf and Skinner, 1970;Clark and Kelly, 1976;Pedersen, 1980;Marshall and Gilligan, 1993). The small pyrite and arsenopyrite grains are anhedral or subhedral crystals while the coarser grains are typically subhedral to euhedral (Fig.…”

Understanding Mineral Deposits

“…Marshall and Gilligan (1993) have discussed several guidelines, the application of which ''require a thorough geometric and kinematic analysis on all scales," and the task is a difficult one. Both are capable of yielding the same or similar geometric relationships, fluid inclusion data, fluid chemistry, and metal and sulfur sources.…”

Zn and Pb mobility during metamorphism of sedimentary rocks and potential implications for some base metal deposits

“…The extraction of base metals, especially Pb, from deeper crustal levels has been previously suggested and is supported by fluid inclusion data and isotope signatures (Beaudoin et al 1992ab;Costagliola et al 1999). The recognised high solubility of Pb and Zn at high temperatures (e.g., Helgeson 1969;Hemley et al 1992) provides the thermodynamic base for models in which metamorphosed base metal deposits lose Pb and Zn to the metamorphic fluids that then potentially deposit these metals into late-metamorphic structures (Marshall and Gilligan 1993;Tomkins et al 2007). Nevertheless, it has proven difficult to quantify the amounts of dissolution of base metals in these and similar source region environments.…”