1. 3D Mineral Mapping of the Rocklea Dome Channel Iron Ore Deposit
Maarten Haest1, Tom Cudahy1, Carsten Laukamp1, Sean Gregory2
1Western Australian Centre of Excellence for 3D Mineral Mapping (C3DMM), CESRE
2Murchison Metals Ltd.

2. Interpretation of visible-near to shortwave infrared reflectance drill core data from a channel iron deposit in the Hamersley Province (WA)
Channel iron deposits (CID) 2nd most important source for Fe production in WA
CIDs developed along Tertiary paleochannels
Fe-(oxyhydr-)oxide pelletoids and ferruginised wood fragments, cemented in goethite matrix
Rare detrital components (e.g. qtz, BIF fragments or clays)
Many pelletoids are ooids, with hematite or goethite core and goethite shells
Morris et al. (1993)
One major step to achieving this vision is the generation of an ASTER satellite geoscience map of Australia (~18
products), which provides mineral group information of value for mapping the regolith, primary geology as well
as superimposed metamorphic and metasomatic alteration affects. This involves ~4000 ASTER multi‐spectral
(14 bands) scenes collected between 2000 and 2008 provided by NASA/ERSDAC/USGS. Specific applications of
these maps include: (1) more accurate mapping of transported versus in situ materials to improve drill hole
planning; (2) recognition of mineral vectors to ore systems; and (3) baseline environmental mapping prior to
resource development.
Ramanaidou et al. (2003)

3. Interpretation of visible-near to shortwave infrared reflectance drill core data from a channel iron deposit in the Hamersley Province (WA)
internal variations of ore types in CID (pure endmember forms in figure to the right):
Vitreous goethite
often ass. with silica
wide CFA above 900nm
steep reflectance slope between and 1800nm
Ochreous goethite
powdery, strong yellow colour
often ass. with Al-clays
“Original” CID
usually goethite (hematite) pelletoids, mixed with ferruginised wood fragments in goethite matrix
One major step to achieving this vision is the generation of an ASTER satellite geoscience map of Australia (~18
products), which provides mineral group information of value for mapping the regolith, primary geology as well
as superimposed metamorphic and metasomatic alteration affects. This involves ~4000 ASTER multi‐spectral
(14 bands) scenes collected between 2000 and 2008 provided by NASA/ERSDAC/USGS. Specific applications of
these maps include: (1) more accurate mapping of transported versus in situ materials to improve drill hole
planning; (2) recognition of mineral vectors to ore systems; and (3) baseline environmental mapping prior to
resource development.
from Maarten Haest

4. Rocklea Dome CID ASTER Airborne hyperspectral 14DD hylogged
~150 RC hylogged
iron oxide (B4/B3)
low
high
One major step to achieving this vision is the generation of an ASTER satellite geoscience map of Australia (~18
products), which provides mineral group information of value for mapping the regolith, primary geology as well
as superimposed metamorphic and metasomatic alteration affects. This involves ~4000 ASTER multi‐spectral
(14 bands) scenes collected between 2000 and 2008 provided by NASA/ERSDAC/USGS. Specific applications of
these maps include: (1) more accurate mapping of transported versus in situ materials to improve drill hole
planning; (2) recognition of mineral vectors to ore systems; and (3) baseline environmental mapping prior to
resource development.

5. Rocklea Dome CID
Channel iron ore
iron oxide

6. : RC cores with XRF
: RC cores with XRF + HyLogging
Haest et al. (2012a, b)

8. “hyperspectral” Fe3+ content – Rocklea Dome data
RMSE: 9.1 wt% Fe
XRF Fe2O3 content
HyLogger 900 nm absorption depth
(900D – fitted 2nd order polynomial nm)
SiO2 wt% XRF
Haest et al. (2012a, b)

9. Iron ore resource delineation
Haest et al. (2012a, b)

10. Iron ore type characterisation
Ochreous goethite: soft and powdery
Vitreous goethite: hard and shiny

11. Clay type characterisation
Haest et al. (2012a, b)

12. Kaolin crystallinity (airborne+drillcore) Height exaggeration: 12*
modelled CID resource
modelled base of channel

13. Conclusions – Rocklea Dome
Quantitative mineralogy from surface and subsurface infrared spectroscopic data, when processed in 3D provide
Rapid iron ore resource delineation
Iron ore type characterisation  processing
Clay mineralogy  geotechnical purposes
Clay composition  guide to CID exploration potential
Airborne hyperspectral (and satellite multispectral data) can be used for CID exploration and characterisation
Same routines are being applied to diamond and rock chip drill cores from BHP Billiton’s BID and CID deposits in the Hamersley Range and to many other commodity types across Australia

14. Further Reading
Cudahy, T.J., and Ramanaidou, E.R., 1997, Measurement of the hematite: goethite ratio using field visible and near-infrared reflectance spectrometry in channel iron deposits, Western Australia: Australian Journal of Earth Sciences, v. 44, p. 411−420.
Haest, M., Cudahy, C., Rodger, A., Laukamp, C., Martens, C., Caccetta, M. (2013): Unmixing vegetation from airborne visible-near to shortwave infrared spectroscopy-based mineral maps over the Rocklea Dome (Western Australia), with a focus on iron rich palaeochannels.- Remote Sensing of Environment, 129,
Haest, M., Cudahy, T., Laukamp, C., Gregrory, S. (2012): Quantitative mineralogy from visible to shortwave infrared spectroscopic data - I. Validation of mineral abundance and composition products of the Rocklea Dome channel iron deposit in Western Australia.- Economic Geology, 107,
Haest, M., Cudahy, T., Laukamp, C., Gregrory, S. (2012): Quantitative mineralogy from visible to shortwave infrared spectroscopic data - II. 3D mineralogical characterisation of the Rocklea Dome channel iron deposit, Western Australia - Economic Geology, 107,
Ramanaidou, E.R., Morris, R.C., and Horwitz, R.C., 2003, Channel iron deposits of the Hamersley Province, Western Australia: Australian Journal of Earth Sciences, v. 50, p. 669−690.

15. Thank you CSIRO Earth Science and Resource Engineering
Carsten Laukamp Geoscientist t e w
Western Australian Centre of Excellence for 3D Mineral Mapping/ MDU Flagship