Dr Alan J MaugerGeological Survey of South Australia

2 December 2019, IOCG Workshop, Adelaide

Alteration at the Olympic Dam IOCG-U Deposit

Olympic Dam

• World’s largest endowment of contained metal

• Au, Cu, Ag, U – highly economic

• What can HyLogger tell us that BHP Billiton don’t already know?

Location of Olympic Dam

In relation to Gawler Silicic Large Igneous Province

After McPhie et al

What minerals can be measured?

• Not all minerals have a distinctive spectral response at the wavelengths HyLogger measures

• SWIR

– OH Bond predominantly, harmonics

• TIR

– Primary molecular vibrations

What the HyLogger saw…SWIR00 = Opal01 = Dickite ‘02 = Kaolinite-PX03 = Kaolinite-WX04 = Nacrite05 = Muscovite06 = Paragonite07 = Phengite08 = Montmorillonite09 = Nontronite10 = Saponite11 = Diaspore12 = Gibbsite13 = Prehnite14 = Pyrophyllite15 = Topaz16 = Chlorite-Fe17 = Chlorite-FeMg18 = Chlorite-Mg19 = Biotite20 = Phlogopite21 = Actinolite22 = Hornblende23 = Tremolite24 = Riebeckite

25 = Serpentine26 = Brucite27 = Talc28 = Epidote29 = Zoisite30 = Tourmaline31 = Tourmaline-Fe32 = Rubellite33 = Ankerite34 = Siderite35 = Calcite36 = Dolomite37 = Magnesite38 = Alunite-K39 = Alunite-Na40 = Alunite-NH41 = Gypsum42 = Jarosite43 = Palygorskite44 = Vegetation-Dry45 = IsaWhite46 = IsaYellow47 = PlasticChipTray48 = Teflon49 = WhiteMarker50 = Wood

51 = YellowMarker52 = MuscoviticIllite53 = ParagoniticIllite54 = PhengiticIllite

TIR000 = Opal001 = Quartz002 = Anorthoclase003 = Microcline004 = Orthoclase005 = Albite006 = Anorthite007 = Bytownite008 = Labradorite009 = Andesine010 = Oligoclase011 = Andradite012 = Grossular013 = Uvarovite014 = Almandine015 = Spessartine016 = Augite017 = Diopside

018 = Hedenbergite019 = Enstatite020 = Fayalite 021 = Forsterite022 = Olivine023 = Zircon024 = Andalusite025 = Cordierite026 = Marialite027 = Meionite028 = Vesuvianite029 = Analcime030 = Chabazite031 = Heulandite032 = Laumontite033 = Mesolite034 = Natrolite035 = Phillipsite036 = Thomsonite037 = Kaolinite038 = Kaolinite-PX039 = Illite040 = Muscovite041 = Paragonite042 = Mont-

morillonite

043 = Mont-morillonite-Na

044 = Nontronite045 = Smectite-Fe046 = Saponite047 = Axinite048 = Prehnite049 = Pyrophyllite050 = Topaz051 = Chlorite052 = Biotite053 = Phlogopite054 = Stilpnomelane055 = Actinolite056 = Amphibole-

ML48057 = Edenite058 = Ferro-

hornblende059 = Hornblende060 = Kaersutite061 = Tschermakite062 = Anthophyllite063 = Gedrite064 = Grunerite065 = Holmquistite066 = Mangano

cummingtonite067 = Arfvedsonite068 = Glaucophane069 = Riebeckite070 = Antigorite071 = Chrysotile072 = Lizardite073 = Talc074 = Clinozoisite075 = Epidote076 = Zoisite077 = Tourmaline078 = Cerussite079 = Smithsonite080 = Strontianite081 = Witherite082 = Azurite083 = Malachite084 = Ankerite085 = Rhodochrosite086 = Siderite087 = Aragonite088 = Calcite089 = Dolomite090 = Dolomite-Fe091 = Magnesite

092 = Alunite-K093 = Alunite-Na094 = Barite095 = Gypsum096 = Jarosite097 = Apatite098 = Vonsenite099 = Cassiterite100 = Goethite101 = Hematite102 = Ilmenite103 = Magnetite104 = Chromite105 = Gahnite106 = Psilomelane107 = Pyrolusite108 = Rutile109 = Palygorskite

163substances

82 - OD

Which wavelength region is best?

What the HyLogger saw…

Location2013 – Section A-A – 30 Holes

2018 – Section B-B – 24 Holes

2013/18 – 75 Holes completed

Current campaign 60% completed

Preliminary Plots from 75 Holes

White Mica Story

2013 -2014 Transect

• The remaining slides focus on Section A-A

Feldspar Story

• Absence of Albite (?)

• HyLogger identified Plagioclase

• Alkis revealed presence of Plagioclase

• HyLogger maps Orthoclase and Microcline as distinct K-Feldspar species

• Plotted the HyLogger results in a QAP diagram

K-Feldspar in the TIR

Orthoclase

Microcline

Mixtures compare slopes

For the sake of modelling

• Calculated single value per hole

• Used “metres of mineral” as an approximation of abundance in a hole.

• Wavelengths – used averages

• Assays – used maximums

Copper values

Sericite and ChloriteSe

rici

te:

Dec

reas

ing

Al

Ch

lori

te:

incr

easi

ng

Fe

K-Feldspar and Plagioclase

Microcline Orthoclase

OligoclaseAlbite

QAP (modified)

Biotite OutDistal

Barren Core

OreQ – QuartzA – K-FeldsparP – Plagioclase

From 1D to 2D

• Next few slides depict cross sections derived from HyLogger data and presented in GoCAD

• Blue is low number (wavelength or abundance). Red is a high number.

Cu ppm

Orthoclase

Microcline

Albite

> An10

Scale: 3,000 m

Illite

Muscovite

Phengite

W2200

Scale: 3,000 m

W2250

Fe-Chlorite

Mg-Chlorite

K/Al ratio

Scale: 3,000 m

Disclaimer

The information contained in this presentation has been compiled by the Department for Energy and Mining (DEM) and originates from a variety of sources. Although all reasonable care has been taken in the preparation and compilation of the information, it has been provided in good faith for general information only and does not purport to be professional advice. No warranty, express or implied, is given as to the completeness, correctness, accuracy, reliability or currency of the materials.

DEM and the Crown in the right of the State of South Australia does not accept responsibility for and will not be held liable to any recipient of the information for any loss or damage however caused (including negligence) which may be directly or indirectly suffered as a consequence of use of these materials. DEM reserves the right to update, amend or supplement the information from time to time at its discretion.

Contact

Department for Energy and Mining – Mineral Resources DivisionGeological Survey of South Australia

Level 4, 11 Waymouth StreetAdelaide, South Australia 5000

T: +61 4 3283 5504E: alan.mauger@sa.gov.au