Smart Exploration: from legacy data to state-of-the-art data acquisition and imaging
A. Malehmir, G. Donoso, M. Markovic, G. Maries, L. Dynesius, B. Brodic, N. Pecheco, P. Marsden, E. Bäckström, M. Penney and V. Araujo
Journal name: First Break
Issue: Vol 37, No 8, August 2019 pp. 71 - 74
Special topic: Legacy Data
Info: Article, PDF ( 615.82Kb )
During the last decade, and possibly in years to come, miner-al exploration geophysics has strongly pushed itself towards developing new instruments and hardware solutions capable of addressing the ever challenging near-mine and brownfield explo-ration issues. New data will be acquired but higher noise levels and restricted access due to mining activities and infrastructure increase the challenge of acquiring data of sufficient quality to answer key geologic questions and define additional resources. Companies that value their existing data and reassess them rigorously and continuously are likely to benefit. However, new generations of geophysicists and mineral explorationists tend to prefer modern data from new instruments than the so-called ‘legacy data’. Legacy data by definition are those that have been acquired in the past, but their revival requires a significant amount of time and money, and still it may not always be possible to yield rewarding results. These data often suffer from bad documentation, inaccurate co-ordinates, and are stored on devices (e.g., tapes or hard copies) that makes it difficult to access or they may have partly been corrupted. However, legacy data are still valuable, especially if they are from brownfield or near-mine exploration sites and can be revived and reworked. Legacy data have the advantage of: • being less contaminated by noise from mining activities and infrastructures, • being acquired in places that now might be inaccessible (i.e., logistical challenges), • being cheaper to reprocess and reinterpret than to collect new data as data acquisition often makes up the bulk of a survey’s cost. Legacy data can also provide a first assessment if new and advanced data acquisition would lead to new knowledge and discoveries. Smart Exploration, an H2020-funded project involving 27 partners from nine European countries and six exploration sites was launched in late 2017. Its goal is to address some of these challenges concerning legacy data, to develop new geophysical instruments for a wide range of applications and to generate new targets at the explo-ration sites while training new generations of young professionals for these purposes. Here, we focus on re-evaluating the potential of some of the legacy data available from the exploration sites and together with new instruments developed during the project present how in-mine and brownfield mineral exploration can advance utilizing existing mining infrastructure. For example, we show the importance of legacy data from a 1996 dataset enabling imaging of a world-class +150 Mt massive sulphide deposit at depth as well as another case study showing that additional iron-oxide resources may be present downdip and under the known mineralized bodies. The development of a GPS-time system and an E-vibrator helped to then acquire a semi-3D tunnel-surface seismic dataset utilizing exploration tunnels in the Neves-Corvo mine.