Wardell Armstrong International
Steve McRobbie, BSc, MSc, ACSM, MAusIMM, Regional Director (Russia)
Steve is an experienced professional exploration and project manager, he is hands-on and has project managed in a variety of demanding overseas environments. He has a proven track record in exploration and resource management in adding value to projects and possesses a wide range of technical and managerial skills and competency. Steve is also a Competent Person as defined by the JORC code (2012). Steve has nearly 30 years’ experience in mining and exploration geology for gold, base metals, diamonds and uranium, and has held senior management roles and local directorships in Africa and the CIS. Has a broad range of operational experience specialising in porphyry deposits having worked on a number of high-profile development projects in Central Asia and Russia involving copper-gold and molybdenum deposits. Steve also has diverse experience geographically, in Africa on gold, base metal and diamond projects in Tanzania, RSA, West Africa, Angola and Botswana. Steve is a strong communicator on the ground and at board level and is not afraid to reassess and challenge preconceived views on projects and bring fresh ideas, looking to add value to projects.
Implication for new exploration techniques from studies of fluid-flow pathways and alteration in porphyry copper systems using examples from Central Asia
Global grades of large prospective porphyry copper targets worldwide are decreasing <<0.4%Cu with pressure to increase plant throughputs >50mtpa.
Lower grade systems will be the norm for exploration which will not have the comfort of steady, uniform disseminated grade envelopes of the 20thC models. Instead higher grade valuable core elements, Cu, Au, Mo will be much more selective in their distribution and closely related to mineralogy, structure and fluid-flow pathways driving the hydrothermal system. There will be a need to best capture distribution of these elements during a definition phase study particular as gold and molybdenum do not always follow copper and can 'make or break' the economics of a project during early years production.
The Geology Research Group at the University of St Andrews in Scotland is currently undertaking field research on using anisotropy in out-of-phase magnetic susceptibility (AMS) of sulphide minerals to investigate if there is a distinct footprint that provides a vector of sulphide mineralisation. This vector may be different from the main structural fabric allied to porphyry emplacement but directly related to fluid flow and selective high grade mineralisation. It is hoped that the AMS response, coupled with hyperspectral mapping of alteration, may prove a powerful tool in mapping relevant fluid-flow and directing search parameters for evaluation and exploration of porphyry systems.