data integration: using geochemical data
DESCRIPTION
Fiona Eddison from MinTarget and Heidi Pass from Reflex Geochemistry present on data integration: adding value to geochemical data at MapInfo Forum 2014 in Perth. http://www.mapinfo.com/TRANSCRIPT
MapInfo Forums 2014Data integration: using
geochemical data Fiona Eddison, MinTarget
Heidi Pass, Reflex Geochemistry
2 MapInfo Forums 2014
Overview of organisations
Fiona Eddison
MinTarget geological consulting
Heidi Pass
Senior Geochemist
REFLEX Geochemistry — a leader in innovative, technology based
data collection, analysis and interpretation of geological results for
the global minerals industry
http://iogas.net www.reflexinstruments.com
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Business Problem
Identifying and ranking mineral exploration targets using soil
geochemistry, geology and geophysics
How can I quickly and effectively add value to my maps using
geochemical data?
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The Solution
Use MapInfo Discover and ioGAS software:
ioGAS
Specially developed for exploratory and geochemical data analysis,
offering tools and workflows for efficiently interpreting your data
Contains MapInfo export functions for data and images
MapInfo “Discover” import tool
Provides a live link to data in ioGAS
Allows integration with “non-geochemical” datasets to assist in decision
making
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Probability plots Log scale
Selected target elements for orogenic Au:
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Probability plotsLinear scale
Selected target elements for VHMS mineralisation:
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Probability plots Log scale
• Compare and contrast with orogenic Au plots
• Pick suitable elements
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X vs Y plots with data trendsFe vs selected indicator elements
• Data for two nearby regions coloured separately
• Reveals different trends for each group
• Statistically treat the data separately
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South prospect data
Just one linear
trend in CuClear, linear
trend in Pb
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Raw Cu Grid
Can you spot the anomaly?
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What are regression residuals?
+ve
residual
-ve
residual
The residuals, distance-parallel to the y axis above and below the fitted line,
are useful. Those greater than 2.5 std dev are considered outliers.
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Cu–Fe residuals for the South prospect
Small triangles depict -ve
residuals (depletion)
Large triangles depict +ve
residuals (enrichment) —
note that Cu values are not
necessarily high
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Cu–Fe residuals map
Export as georectified attribute map to load into MapInfo or use data
“on the fly”
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Gridded images of raw & residual
Cu data
Raw Cu data Cu residuals based on Fe
Compare the images below and pick the anomalies
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Gridded images of raw & residual
Cu data — anomalies
Raw Cu data Cu residuals based on Fe
Potentially interesting areas are circled
Note downgraded area
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MapInfo geology attributes and ioGAS
geochemistry
Points coloured up according to geology code obtained from MapInfo
and shaped to show residuals to see if the story holds up
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MapInfo’s ioGAS Importer tool
Load tool (located in Encom folder)
Match up Sample ID and co-ordinate
columns
Select the columns for import
Select all or visible-only data
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X vs Y plots Selected elements for orogenic Au targeting
Example: North prospect orogenic Au (red points)
Data clustered on line of best fit for XY plots for ‘Fe vs As’ & ‘Fe vs Ba’
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Ranked variable mapsNorth prospect
Percentile-based maps in just one click in ioGAS, but what is the best way to
see the relationship between all three?
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RGB imageA quick three-element tools in ioGAS to identify element zonation
and co-occurrence
90th percentile cut
off = top 10% of
the data
Au
Ba
As
Ba & Au
As & Au
Au&Ba
&As
Ba & As
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Consider all data in MapInfoOverlay datasets — surface and interpreted geology, geophysics, DEM,
geochem, etc (images below use GSWA geology, 2VD-TMI & Au/Ba/As as RGB)
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Check interpretation
M = Mafic
F = Felsic
D = Dyke
Au
Ba
As
Flexure in fault
Flexure in dyke
Au assoc w/
fault and geol
bndry?
Extend
geochem
survey
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Outcomes and lessons learnt
Integrating MapInfo Discover and ioGAS allows smooth workflow
between the mapping and geochemical environments to add value to
your geological interpretations;
Use MapInfo to join geology attributes to geochemical data
Use ioGAS to assess geochemical data suitability and determine
appropriate statistical methods
Use ioGAS to conduct linear regression analysis and
automatically attribute statistically significant anomalies; ID
element zonation and co-occurrence
Import data into map space using MapInfo to interpret “on the fly”;
images can be imported, too
Compare the interpreted geochemistry with other key datasets
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Questions?