The use of mineral exploration drilling to kickstart hydrogeology data collection for pre-feasibility mining studies and beyond (2021)
Kym L Morton
KLM Consulting Services Pty Ltd, PO Box 119, Lanseria, 1748, South Africa,
Abstract
Valuable groundwater information becomes available as soon as drilling starts, particularly during early mineral exploration campaigns. Often the information is not collected as the value does not become evident until the exploration sites become a mine. This paper describes what information can be collected very inexpensively during exploration drilling and how drill holes can be used to create an early monitoring network for the collection of water levels across the site. Examples of logging sheets, daily drill records and construction designs for monitoring boreholes are provided.
During drilling and logging of exploration coreholes the emphasis is all on characterising the orebody. Drilling methods include rotary, air percussion and core drilling. All encounter water and, with very little effort, the information on water intersections, drilling fluid circulation losses, basic water chemistry and rest water levels can be collected by the drilling contractor and the site geologist, under direction from the project managers.
If the basic information is captured, then this significantly reduces the cost of the initial hydrogeological study for the pre-feasibility reports. Some of the holes can be equipped for use as water level monitoring boreholes or preserved for use at a later stage. Old core holes that are not sealed can create conduits for underground inflows when the mine is developed.
Decision criteria are provided for the use of the hole after drilling to optimise information from all drillholes and reduce risk when mining commences.
Keywords: Water, Mine Design, Inflow, Flood, Precipitation, PFS
Morton, K.L. (2021) ‘The use of mineral exploration drilling to kickstart hydrogeology data collection for pre-feasibility mining studies and beyond’, International Mine Water Association Annual Conference, Wales, 2021.