Data Integration: Using Geochemical Data

MapInfo Forums 2014Data integration: using

geochemical data Fiona Eddison, MinTarget

Heidi Pass, Reflex Geochemistry

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Overview of organisations

Fiona Eddison

MinTarget geological consulting

mintarget@optusnet.com.au

Heidi Pass

Senior Geochemist

heidi.pass@imdexlimited.com

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?