Application of hyperspectral data for assessing 3D lithological and alteration architecture of porphyry Cu-Au systems

Jamie Robinson David Tilley, Charlotte Barry, Peter Downes, John Greenfield, Joel Fitzherbert and Phil Blevin

This work is part of the surveys efforts to develop training or system type characterisation datasets

We want to get to a point where we can develop spatial vectors into systems • To do this, how we collect and process our data is very important • Need to break-up/domain data to isolate variables

Need to be able to identify ‘anomaly’ from ‘background’ • Nymagee type system the transition from background into the alteration system

is over scales of tens of metres • For Cargo, we are not seeing the edge of the system. The transition is likely to be

over kilometres or tens of kilometres

Need broader-regional scale datasets. How? • As well as drill core/chips, hyloggerTM can scan slabs/rock samples

We need to move from looking at hyperspectral logged drill holes in isolation, and start to look at mineralogical variability over mineral system scale, rather than the drill hole scale

Even in simple systems you cannot directly plot

meaningful system scale spatial mineralogy

Projects aim to fill the gap between hyperspectral data collection and exploration outcomes

?

How do we take the raw data, process, validate and provide an outcome which has significant

system vectoring application?

Limitations of Hylogger that need to be recognised to examine the data: • The hylogger outputs mineral point count data • Recognition of minerals within the core can be

affected by: • Grain size • Grain orientation • Mineral colour/reflectivity

• The output point count data is based on matching spectral signatures of scanned points against signatures in the TSG library

• Current work only based on shortwave infrared (clays, phyllosilicates, amphiboles, sulphates, carbonates).

Downes et al in review

Strongly shoot controlled Cu within a NNW trending fault zone

Metamorphosed clay-rich • Quartz–muscovite/illite • Minor scattered plagioclase

& chlorite • Trace K-feldspar

Quartzo-feldspathic • quartz–muscovite-

plagioclase • minor chlorite • trace K-feldspar

white mica

feldspar

Fe-chlorite

Mg-chlorite

sulfides (aspectral) & Fe-oxide

quartz The margins of the alteration system are clearly observed across strike

Melrose Melrose Melrose Melrose Melrose Melrose Melrose Melrose Melrose TroughTroughTroughTroughTroughTroughTroughTroughTrough

Rast Rast Rast Rast Rast Rast Rast Rast Rast TroughTroughTroughTroughTroughTroughTroughTroughTrough

Canbelego - Mineral Canbelego - Mineral Canbelego - Mineral Canbelego - Mineral Canbelego - Mineral Canbelego - Mineral Canbelego - Mineral Canbelego - Mineral Canbelego - Mineral Hill Rift Zone Hill Rift Zone Hill Rift Zone Hill Rift Zone Hill Rift Zone Hill Rift Zone Hill Rift Zone Hill Rift Zone Hill Rift Zone

Mount Hope Mount Hope Mount Hope Mount Hope Mount Hope Mount Hope Mount Hope Mount Hope Mount Hope Trough Trough Trough Trough Trough Trough Trough Trough Trough

Winduck Shelf Winduck Shelf Winduck Shelf Winduck Shelf Winduck Shelf Winduck Shelf Winduck Shelf Winduck Shelf Winduck Shelf

Walters Walters Walters Walters Walters Walters Walters Walters Walters Range Range Range Range Range Range Range Range Range Shelf Shelf Shelf Shelf Shelf Shelf Shelf Shelf Shelf

Wiiltagoona Shelf Wiiltagoona Shelf Wiiltagoona Shelf Wiiltagoona Shelf Wiiltagoona Shelf Wiiltagoona Shelf Wiiltagoona Shelf Wiiltagoona Shelf Wiiltagoona Shelf Kopyje Shelf Kopyje Shelf Kopyje Shelf Kopyje Shelf Kopyje Shelf Kopyje Shelf Kopyje Shelf Kopyje Shelf Kopyje Shelf

Winduck ShelfWinduck ShelfWinduck ShelfWinduck ShelfWinduck ShelfWinduck ShelfWinduck ShelfWinduck ShelfWinduck Shelf

Cobar Trough Cobar Trough Cobar Trough Cobar Trough Cobar Trough Cobar Trough Cobar Trough Cobar Trough Cobar Trough

Winduck Shelf Winduck Shelf Winduck Shelf Winduck Shelf Winduck Shelf Winduck Shelf Winduck Shelf Winduck Shelf Winduck Shelf

Beloura Tank

Boomerang Tank

Kilparney

Mountain dam

White Tank

Rookery

Booth

Blue Mountain

Stoney Tank

Elura

Lerrida

McKinnons Tank

Kirry

Wiralong

Lillvale

Mineral HillMineral HillMineral HillMineral HillMineral HillMineral HillMineral HillMineral HillMineral Hill

Tallebung MineTallebung MineTallebung MineTallebung MineTallebung MineTallebung MineTallebung MineTallebung MineTallebung Mine

Girilambone MineGirilambone MineGirilambone MineGirilambone MineGirilambone MineGirilambone MineGirilambone MineGirilambone MineGirilambone Mine

TrittonTrittonTrittonTrittonTrittonTrittonTrittonTrittonTritton

Pipeline RidgePipeline RidgePipeline RidgePipeline RidgePipeline RidgePipeline RidgePipeline RidgePipeline RidgePipeline Ridge

Nymagee Copper MineNymagee Copper MineNymagee Copper MineNymagee Copper MineNymagee Copper MineNymagee Copper MineNymagee Copper MineNymagee Copper MineNymagee Copper Mine

Mt Boppy MineMt Boppy MineMt Boppy MineMt Boppy MineMt Boppy MineMt Boppy MineMt Boppy MineMt Boppy MineMt Boppy Mine

Nymagee - HeraNymagee - HeraNymagee - HeraNymagee - HeraNymagee - HeraNymagee - HeraNymagee - HeraNymagee - HeraNymagee - Hera

New OccidentalNew OccidentalNew OccidentalNew OccidentalNew OccidentalNew OccidentalNew OccidentalNew OccidentalNew Occidental

Peak Mine Peak Mine Peak Mine Peak Mine Peak Mine Peak Mine Peak Mine Peak Mine Peak Mine PerseverancePerseverancePerseverancePerseverancePerseverancePerseverancePerseverancePerseverancePerseverance

WonawintaWonawintaWonawintaWonawintaWonawintaWonawintaWonawintaWonawintaWonawinta

Gilgunnia Gilgunnia Gilgunnia Gilgunnia Gilgunnia Gilgunnia Gilgunnia Gilgunnia Gilgunnia GoldfieldsGoldfieldsGoldfieldsGoldfieldsGoldfieldsGoldfieldsGoldfieldsGoldfieldsGoldfields

ShutteltonShutteltonShutteltonShutteltonShutteltonShutteltonShutteltonShutteltonShuttelton

May DayMay DayMay DayMay DayMay DayMay DayMay DayMay DayMay Day

Great CobarGreat CobarGreat CobarGreat CobarGreat CobarGreat CobarGreat CobarGreat CobarGreat Cobar

CSA MineCSA MineCSA MineCSA MineCSA MineCSA MineCSA MineCSA MineCSA Mine

CnesneyCnesneyCnesneyCnesneyCnesneyCnesneyCnesneyCnesneyCnesney

New CobarNew CobarNew CobarNew CobarNew CobarNew CobarNew CobarNew CobarNew Cobar

Mt HopeMt HopeMt HopeMt HopeMt HopeMt HopeMt HopeMt HopeMt Hope

Mt Allen MineMt Allen MineMt Allen MineMt Allen MineMt Allen MineMt Allen MineMt Allen MineMt Allen MineMt Allen MineWagga TankWagga TankWagga TankWagga TankWagga TankWagga TankWagga TankWagga TankWagga Tank

EluraEluraEluraEluraEluraEluraEluraEluraElura

Mc Kinnons Mc Kinnons Mc Kinnons Mc Kinnons Mc Kinnons Mc Kinnons Mc Kinnons Mc Kinnons Mc Kinnons TankTankTankTankTankTankTankTankTank

COBARCOBARCOBARCOBARCOBARCOBARCOBARCOBARCOBAR

0km 50km

Rookery Fault

Nymage Fault

Sandy Creek Fault

Gilm

ore linamentW

agga

- Nym

agee

Stru

cture

Woonarra Fault

Rookery Fault

Plug Tank F

Amphitheatre Fault

Jackermaroo F

ault

Buck

war

oon

Faul

t

Coonara Fault

COBAR SUPERBASIN

Simplified Geology and Mineral Deposits

David 2007 Cobar

Sydney

= mineralised zone

Fe-chlorite

Mg-chlorite

NMD053W1 NMD047

Transition from Fe to Mg chlorite proximal to mineralised zone

Consistent finding of broader Cobar-Nymagee Alteration study

Spatial plotting Fe and Mg chlorite should recognise a gradient within the plane of the host structural zone. Potential vector towards mineralisation within the plane of the

host structural zone

Downes et al. in review

Downes et al in review

Much greater alteration complexity associated with Porphyry Cu-Au systems: • Alteration over broader scales • Superposition of assemblages • Prograde and retrograde assemblages • Broader range of pre-, syn and post

mineralisation lithologies

Holliday & Cooke 2007

Cadia

Orange

Bathurst Cargo

Cadia

Bathurst 250k Metalogenic Simplified geology – Downes et al 2013

Orange

Bathurst

Orange Sydney

Stage 1: Translating and simplifying logging code system Stage 2: Data domained by lithology and spatial variability of mineralogy examined between holes evaluated Stage 3: 1st pass point data interpolation

16 holes scanned with Hylogger

Translating and simplifying logging code system

Combination of translating codes to GSNSW system where

textural qualifiers separated from basic lithology code &

checking the logged lithology against spectral signature

e.g. 4 textural variations of andesite merged to one (with textural qualifier)

Numeric data domained by lithology and drillhole

Data does not extend to or beyond the edge of the system to estimate background but clear trends exist in the data

Part of argillic or phyllic assemblage as per Leach 2008 Part of Potassic assemblage as per Leach 2008 Part of propylitic assemblage as per Leach 2008

Why the difference? • Hylogger data needs validation using petrography

and xrd • Possible some biotite variants not

recognised in hylogger data & spectral library needs update

• Biotite may be fine grained or misoriented relative to the scanner

• Biotite may be overestimated in logs

• Biotite may be retrogressing (to Mg Chlorite?)

Note: All current interpolation given identical elipsoid constrains for first pass comparison

First pass anisotropic interpolations Visually Logged biotite within holes scanned

Hylogged data Interpolated biotite-phlogopite

Example: Spatial variation in Fe and Mg Chlorite • As observed in 2D plots of

domained data, Fe and Mg chlorite

• Mg chlorite appears spatially

related to copper, Fe chlorite occurs on margins

• Margins of system are not

constrained by current scanned drillholes

The Nymagee study demonstrated in a relatively simple system that the background metamorphic mineralogy can be separated

from alteration mineralogy

Increased Mg chlorite relative to Fe chlorite could be used as an indicator of proximity to mineralisation

In the more complex porphyry systems we need to domain data to better isolate mineral gradients

However, there are trends in the hylogger data that can be

recognised at this early stage

Validation of observations in first pass analysis (petrography & XRD)

Use thermal Infrared data

Characterisation of plagioclase

Determination of alteration vs magmatic K feldspar

How does the observed alteration relationship compare to magnetic susceptibility?

Re-evaluate methods and relationships in other systems