Halo Technology™ (Halo) is a next-generation scientific technology with over 20 years of development and evaluation in our Australian labs. Halo powers our Geochemical Exploration Program, which is available to Australian and international mining and exploration companies. 

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Scientific Background

Most of the ore bodies with surface or near-surface expression have already been discovered. The next generation of exploration targets will be below cover and over 100m deep. Over 60% of Australia is covered by overburden to an extent that makes it geochemically sterile to conventional exploration methods.

Unparalleled depth detection
Halo has been used to detect sub-cropping, buried and blind, base metal mineralization at depths of approximately 165m. Conventional geochemistry cannot be relied upon to identify any buried and blind ore bodies below deep cover as any potential anomaly is likely to not be distinguishable from background, using this protocol.

Highly sensitive process
Halo employs a biochemically based leaching protocol that dissolves hydromorphically deposited elements from only the surface of soil grains. The analytical process functions with exceptionally low detection limits, which improves the possibility of finding the surface signature of a sub-cropping buried or blind orebody.

Composition of soil particles
Soil particles generally consist of a core of un-weathered primary rock material of variable thickness and a layer of weathered and degraded secondary material surrounding this core. Surrounding this is an extremely thin (picometres to nanometres) tertiary coating of deposited salts from evaporated solutions that have originated at depth and have migrated to the surface by capillary action and evapotranspiration.

Mineral salt leaching
Mineral salts are leached from rocks by circulating subterranean water migrating to the surface. These salts are derived from both mineralised and un-mineralized sequences and will reflect the geochemistry of the rocks they are leached from. Consequently, the evaporated coatings of soil grains at or near the surface will reflect the sub-cropping geochemistry and any mineralised sequence of rocks or orebodies that exist below the surface under the superimposed soil cover.

Pathfinder element leached from orebody
If a migrating solution passes through an orebody on its way to the surface, it will leach metals that are uncharacteristic of any normal lithological sequence and will leach enhanced levels of so-called pathfinder elements reflecting the mineralization. Consequently, on evaporation of the migrating solution, soil particles are coated with these pathfinder elements at elevated levels. Although composing a relatively small part of the soil particle, if these elements can be preferentially leached they will give a significant anomaly that will be capable of improving the geochemical signature of the orebody at the surface. It is this coating that Halo targets.

Sampling

  • Leaching is performed on a dried soil sample using screened particles (<300 μm diameter).
  • Halo targets and extracts elements from primarily the outer deposited coating on the soil particle.

Comparison to chemical leaching and conventional geochemistry

The graph below illustrates comparative data from an actual exploration traverse in deep cover showing the enhanced sensitivity of the Halo service, and the obvious differences in the magnitude of an anomalous region over a deep-seated orebody, that can be achieved using this technology.

Halo uses state-of-the-art Inductively Coupled Plasma Mass Spectrometry (ICP-MS) to achieve high levels of precision and accuracy and extremely low detection limits. 

ICP-MS is used to determine analyte concentrations down to parts per trillion. This low level of detection means that even very low analyte concentrations can be determined with a high level of precision, giving greater confidence in using a multi-element interpretational approach to identify the possibility of sub-cropping mineralisation.

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Using traditional chemical leaching and geochemistry, many geochemical exploration initiatives will fail to identify potential economic mineralization because they cannot distinguish between background and the suppressed response over anomalies associated with buried and blind ore bodies.

Click on the image below to enlarge

Halo is a next-generation scientific technology with over 20 years of development in our Australian labs. It is a new, better way for geochemical exploration and an efficient alternative to conventional exploration methods and is the technology of choice for detecting buried and blind ore-bodies.

Get started with Halo