Low density geochemical mapping and mineral exploration: application of the mineral system concept

Abstract

The mineral exploration industry is used to very high sample densities (100s to 1000s of samples/km 2 ) for geochemical exploration in order to define drill targets. Lately, geoscience organizations in many countries have been geochemically mapping increasingly larger areas at progressively lower sampling densities (1 site/100 to 1 site/18 000 km 2 ). A single ore body is too small a target and cannot be expected to be discovered at such low sample densities; indeed numerous deposits could be hidden within a 100 × 100 km grid cell. However, mineral systems, which include all geological ingredients and processes necessary for the generation of mineral deposits, form much larger targets that could be identified even at such low sampling densities. Examples from some European low density geochemical surveys where patterns emerged that may have implications for mineral exploration are shown and discussed. It is concluded that low density geochemical mapping holds great promise in the early stages of mineral exploration programmes in guiding subsequent effort into the more fertile regions. Interpretation of these maps, however, may need a different approach than that used in classical, high density mapping exercises, where only 'high values' of certain metals are the traditional target.

Environmental Status of Italian Coastal Marine Areas Affected by Long History of Contamination

“…A regular and systematic sampling strategy for the sediment characterization, according to the same principle used for geochemical mapping (Reimann et al, 2010(Reimann et al, , 2015, adaptable to the features (type and extension of the study area) and environmental settings (i.e., industrial plants), was adopted ( Figure 2). The sampling scheme was organized in grids of variable size (from 50 × 50 m to 450 × 450 m), according to the complexity of the site, and transects to cover the remaining areas.…”

Current and emerging analytical techniques for geochemical and geochronological studies

“…The major objective of geochemical exploration in an area is to detect anomalous concentrations of elements that constitute an expression of mineralization. Accuracy is not so important in these initial stages, but the required sensitivity together with precision are extremely important as the method should have the ability to detect and reproduce the subtle geochemical anomalies above background or threshold values (Reimann, Berger, Birke, & Caritat, 2016). The following partial digestion procedure was utilized successfully in geochemical exploration work for base metals in certain parts of Rajasthan, India for the determination of base metals such as Cu, Fe, Zn.…”

Recognition of geochemical footprints of mineral systems in the regolith at regional to continental scales

“…The mineral systems approach is gaining in popularity as a useful concept (e.g. Blewett, 2014;Huston et al, 2016;Jaques, Jaireth, & Walshe, 2002;McCuaig, Beresford, & Hronsky, 2010;Murphy et al, 2011) and is a practical link for the application of (low-density) surface geochemical mapping to mineral exploration (Reimann, Ladenberger, Birke, & Caritat, 2016).…”