High-pressure metamorphism of stratiform sulphide deposits from the Diahot region, New Caledonia

Stratabound Ore Deposits in the Andes

“…They include the Huaripampa and Carahuacra mines, the genesis of which has been discussed by Lyons (1968), Kobe (1977Kobe ( , 1982, Vera (1983) and Dalheimer (this Vol.). They include the Huaripampa and Carahuacra mines, the genesis of which has been discussed by Lyons (1968), Kobe (1977Kobe ( , 1982, Vera (1983) and Dalheimer (this Vol.).…”

“…In the central Pucara only scarce volcanic activity is recorded, mainly as tuffaceous horizons in the Aramachay Formation (Szekely and Grose 1968;Kobe 1977}, but, in certain areas volcanic material is relatively abundant. In the eastern Pucara only few volcanic and subvolcanic rocks of basic composition, as well as some tuffaceous material, are known intercalated in sediments of Norian to Hettangian age.…”

“…Numerous stratabound ore deposits occur in sediments of the Pucara Group Kobe 1977. They belong to different genetic types.…”

“…Barite occurrences are also known within the carbonate sequence in northern and eastern areas of the Pucara basin. ); the Katy manto near Morococha and, according to (Huaman 1983), parts of the Morococha Mine itself; the Malpaso Mine (Kobe 1977(Kobe , 1982, and perhaps part of the Machcan Mine (Hirdes and Amstutz 1978;Hirdes this Vol.). Vanadium minerals, mainly sincosite [CaV(OHiP0 4 )z·3H 2 0, Schaller 1924, formula according to Ramdohr and Strunz 1978], occur in an 18-m-thick horizon of bituminous shales which contain thin layers of volcanic ash Canepa, this Vol.).…”

The Pyrite-Pyrrhotite Transformation as an Ore-Concentrating Geochemical Barrier

“…Together with sulfide bodies included in them, they were subjected to metamorphism during Oligocene-Miocene time, with high pressures corresponding to the lawsonite-albite and glaucophane (blueschist) facies, during which case, pyrrhotite and very iron-rich sphalerite developed. New generations of pyrite appeared in the ore body and in the aureole [9].…”