Daniel Parvaz

Department: Camborne School of Mines
Discipline: Geology
Research Centre/Unit: Economic Geology

Project Summary

Project Title

Development of geochemical and mineralogical methods for targeting lower environmental impact secondary copper deposits in the Troodos Massif, Cyprus

Project summary: The Troodos Massif, Cyprus has been mined since the Bronze Age and contains around 90 copper deposits. Mining has mainly concentrated on the primary, volcanogenic massif sulphide-type deposits containing pyrite and chalcopyrite, with lesser sphalerite. However, the mining of secondary deposits formed from their weathering offers environmental benefits as copper in secondary minerals is more amenable to acid leaching rather than crushing and smelting necessary for sulphide ores. Secondary copper minerals form mainly as a result of oxidation of primary pyrite by percolating meteoric fluids which causes a reduction in pH of the fluids and subsequent dissolution of chalcopyrite. Much of the Cu enters the fluid phase and is precipitated at deeper levels as either oxides, above the water table, or as sulphides below it.

Key project objectives:

The aim of the project is to develop new exploration tools for secondary Cu deposits by testing the hypotheses that: gossans (oxidised surficial sulphide deposits) can be classified, using mineralogical and geochemical criteria, into different types and that these gossan-types can be used to predict the existence of potentially economic secondary copper deposits at depth. Five gossans will be studied: the Phoenix and Three Hills deposits, with known secondary Cu mineralisation; two ‘barren’ gossan sites, to be identified during fieldwork; and the West Apliki prospect, which is as yet undeveloped, with the objective of testing this exploration method.

 

A classification scheme for gossans known to be formed from high- and low-Cu protoliths will be devised on the basis of the presence/absence of relict minerals and replacement textures and the mineralogy and elemental composition of weathering phases, including clays. The extent and nature of the weathering in gossans from high-Cu protoliths will be assessed by carrying out mass balance calculations using bulk and mineral geochemical data.  

Supervisory Team

Dr. Ben Williamson – (Camborne School of Mines)

Dr. Richard Herrington – (Natural History Museum)

Dr. Jon Naden – (British Geological Survey)

Wider Research Interests

Volcanogenic Massive Sulphide (VMS) formation

Supergene processes forming secondary Cu deposits

Provenance of alluvial gold in the UK and Britsh Columbia

Ore deposit generation in relation to magmatic activity