|











| |
Anomaly
Identification
In this study,
the 99th percentile was used to classify samples
as "enhanced" in any element for the purposes of
a MineMatch description. Select from the
following links to view tables showing these
thresholds in the format of your choice.
Thresholds were calculated for the sample
population as a whole, as well as for each lithology
individually.
-
PDF format listing of thresholds
-
PDF format listing of numbers of samples in each lithology population
-
Web page (HTML format) showing all lithologies,
thresholds, and sample populations
-
Excel Spreadsheet with locked lithology column
and column headers showing lithologies,
thresholds and sample populations. [This
requires that the (free) MS Office
Web
Components (16 Mb) are installed on your
computer.]
MineMatch
reports for each Anomaly Cluster list the
anomalous elements which characterise the
cluster, and include, in the "Comments"
column of the report, a statement as to
whether the element is anomalous within the
entire population, the lithology-specific
population, or both populations. (See
examples of each explanation in the graphic
above.)
-
Steve Amor has written a good overview of
geochemical data presentation and
interpretation for exploration, which
includes a discussion of the advantages of
using percentiles to set anomaly thresholds.
It is available for download in summary
<362Kb> and complete
<1.9Mb> form.
|
|
Regional Silt Geochemistry Statistics
A
large number of statistical graphics have been
prepared to assist with the interpretation of
the stream sediment data used in this study, and
to support the use of the 99th percentile as the
threshold above which to regard a sample's
analytical result as "anomalous" or, in
MineMatch terminology, "enhanced".
A special web page has been designed to
facilitate the comparison of data sets, by
lithology, analytical method, or element, using
constant horizontal and vertical plotting scales
when appropriate.
To view these graphics, please click
here.
These plots are likely to be of value beyond the
scope of target generation in minerals
exploration. Environmentalists will be
interested in the information they provide about
stream compositions. Bedrock mappers will be
interested in the extent to which they validate
lumping and splitting of rock types into
different mappable lithological units at a scale
of 1:250000.
-
To compare the geochemistry of lithologies
mapped in the Yukon with lithologies mapped in
neighbouring British Columbia, please click
here.
-
The
GERM geochemical reservoir database
provides a wealth of reference data which is
downloadable in many formats, and which is
useful of comparison with the data reported
in this study.
|
|
Thresholds by Lithology
In this study,
the 99th percentile was used to classify samples
as "enhanced" in any element for the purposes of
a MineMatch description. Select from the
following links to view tables showing these
thresholds in the format of your choice.
Different thresholds were calculated for each
lithlology.
-
PDF format listing of thresholds
-
PDF format listing of numbers of samples in each lithology population
-
Web page (HTML format) showing all lithologies,
thresholds, and sample populations
-
Excel Spreadsheet with locked lithology column
and column headers showing lithologies,
thresholds and sample populations. [This
requires that the (free) MS Office
Web
Components (16 Mb) are installed on your
computer.]
|
|
Anomaly Cluster Geochemical Details The
Anomaly Cluster Details report provides RGS
sample compositions for anomalous samples,
together with 99th
percentile thresholds (lithology and non-lithology-specific),
and the number of samples present in each sample
population.
Click
here
to view Anomaly Cluster Details reports.

Advice on how to use the report, and associated
information, is presented in the
opening
screen, as shown on the right (click to
enlarge).
The report has been
carefully formatted for letter-size printing,
using red, bold and underlining to highlight anomalous values.
By
clicking on the "Find" icon in the report (a
magnifying glass near the top left corner),
Anomaly Clusters may be queried by any
combination of input variables. Use the "help"
facility on the Report page (the button with a
question mark near the top left corner) to find
out more about how to use this very powerful
querying feature.
For example, you can search
for all Anomaly Clusters which have Ni_INA_ppm
>= 260 and Zn_AAS_ppm >= 2200, as illustrated in
the figure on the right (click to enlarge).
The
first cluster satisfying your query should be Cluster No
1085, which is also anomalous in Ba and Mo
- as shown in the figure on the right
(click to enlarge). |
|
|