Samples and Analyses of 2013 WSGS Investigation
This investigation included a survey of various sites across Wyoming. What geologists call grab samples (i.e. small, unmeasured samples, not considered to be representative of a larger volume of material) were collected and the sites recorded. A grab sample only represents one small piece of evidence for the occurrence of a mineral concentration or deposit. Further analysis is required. Analyses of these grab samples can neither confirm nor deny the presence or absence of economic concentrations of REE or other elements.
A thorough evaluation of a deposit, as opposed to a survey of occurrences as presented in this report, requires multiple samples be evaluated across the range of geologic environments that occur at a specific location. Each of those samples must represent a specific volume of relatively uniform material such that elemental concentrations can be converted to tonnage estimates across the deposit. Only then can the economic tenor of the deposit be estimated.
Sample bag containing rare earth elements.
WSGS photo by Wayne M. Sutherland.
Not all samples are equal. The analysis of a panned concentrate from a placer sample is not equivalent to that of a grab sample. A panned concentrate results from washing disaggregated minerals in the field with water to separate out the heavy elements from the lighter ones. Analytical results may show relatively high values for some elements in the concentrate. However, to provide proper perspective, a panned concentrate analysis must be diluted to represent the original larger volume of material from which the concentrate was derived. This dilution may reduce reported values by a factor of 10 to 100 or more, depending on techniques and equipment used in sampling. Placer samples are appropriately described in both the text of this report and in Wyo-DOG.
All sample analyses collected for this project were completed by ALS Chemex of Reno, Nevada. Analytical methods for historic samples included within Wyo-DOG or the report are referred to as generic if either the laboratory or the method of analysis is not known. Geochemical analyses on samples included whole rock analyses (major element concentrations in the form of oxides) by inductively coupled plasma (ICP), atomic emission spectrometry or mass spectrometry, and atomic adsorption. These methods, when preceded by effective preparation techniques, can generally detect most elements present in a sample from very low concentrations in the range of less than 0.1 to 5 parts per million (ppm) up to ore-grade concentrations. To put this in perspective, 1.0 percent is equal to 10,000 ppm.