Soil, Till and Sediment
Soil, till and sediment are well used tools on the Geoscientist’s workbench….
However, the potential of these tools have increased many fold in recent years with powerful new ICP-MS packages and desktop software for geochemical interpretation.
Exploration for blind or buried deposits in both greenfield and brownfield camps demands better analytical methods to avoid the redundancy of past surveys. New laboratory technology providing a broader range of pathfinder elements, lower detection limits and stringent quality control are the drivers for defining the next level of geochemical anomalies to be traced up stream, up ice or beneath cover to the next Chuquicamata or Grasberg.
At BVM we understand the exploration business and the requirement to confidently detect and track subtle, true anomalies to their source. We are at the forefront with innovative packages delivering the needed sensitivity and precision. And we take pride in being the laboratory of first choice for these types of surveys by industry, academia and governments from all over the world.
Soils, tills and sediments typically undergo two stages of preparation consisting of drying and screening. At BVM we dry these materials at 60°C to minimize loss of volatile elements (eg. Mercury). However, for some analyses drying at < 40°C may be required for specific weak leaches. Unless requested otherwise by the client; soils, tills and sediments are screened to -180 microns (-80 mesh ASTM). Clients can request coarser or finer (down to -63 microns) screening depending on the requirements of their program. BVM also offers clay separation so that the finest and most reactive portion of the media can be tested.
Samples are handled, dried and screened in a area dedicated for these media to avoid contamination from more mineralized rock and core samples.
BVM offers the widest array of multi-element packages to suit the needs and budgets of the Explorationist. Analysis consists typically of two stages comprising extraction of the desired elements into a solution and element determination by instrumental analysis of the solution.
Extraction can be partial to measure only the interesting portions (eg. sulphides) of the elements or the extraction can be total to measure the total abundance of the elements from all minerals in the sample.
BVM offers two principle means of determination; ICP-ES and ICP-MS. ICP-ES measures the light-waves and light intensities to determine what elements are present in the solution and the quantities of each. ICP-MS measures the element concentrations by counting the atoms for each element present in the solution. Generally, ICP-MS can determine concentrations that are 1 to 2 orders of magnitude lower compared to ICP-ES.
Typically the ICP-MS or ICP-MS+ICP-ES packages are selected for soil, till and sediment surveys to provide the broadest array of elements coupled with lowest detection limits to ensure maximum exploration power.