Government of Western Australia

Department of Mines and Petroleum

Geological Survey of

Western Australia

WA’s Exploration

Incentive Scheme (EIS)

‘UNCOVER’

Looking beneath the

Nullarbor

Government of Western Australia Department of Mines and PetroleumGovernment of Western Australia Department of Mines and PetroleumGovernment of Western Australia Department of Mines and Petroleum

Exploration Incentive Scheme (EIS)

• Architecture and 4D (3D + time)

– Crustal-scale 2D and 3D models

• Integrate robust interpreted bedrock geology maps

with deep seismic, MT, magnetics and gravity

• Fossil arcs, suture zones and mantle tapping

structures — Mineral Systems

– 4D

• Development through time

– Geochronology and isotopes

Government of Western Australia Department of Mines and PetroleumGovernment of Western Australia Department of Mines and PetroleumGovernment of Western Australia Department of Mines and Petroleum

The Nullarbor: Eucla Basin basement

• Miocene seafloor –– 400 m of

limestone cover

• EIS datasets:

– Airborne magnetics and

radiometrics

• 200 and 400 metre line spacing

– Ground gravity

• 2.5 km stations

– Deep crustal seismic and

magnetotelluric surveys

• Albany–Fraser and Eucla–Gawler

– Industry Co-funded and GSWA

stratigraphic drilling

• Geochemistry, geochronology and

isotopes

Government of Western Australia Department of Mines and PetroleumGovernment of Western Australia Department of Mines and PetroleumGovernment of Western Australia Department of Mines and Petroleum

Airborne magnetics

Government of Western Australia Department of Mines and PetroleumGovernment of Western Australia Department of Mines and PetroleumGovernment of Western Australia Department of Mines and Petroleum

Ground gravity: 2.5 km spacing

(onshore)

Government of Western Australia Department of Mines and PetroleumGovernment of Western Australia Department of Mines and PetroleumGovernment of Western Australia Department of Mines and Petroleum

Deep crustal seismic reflection

and MT surveys

• Albany–Fraser Orogen migrated

cross section images

12GA–AF2 12GA–AF1

12GA–AF3

Government of Western Australia Department of Mines and PetroleumGovernment of Western Australia Department of Mines and PetroleumGovernment of Western Australia Department of Mines and Petroleum

Geochemistry, Geochronology and isotopes:

Madura Province as 1400 Ma oceanic arc

-20

-18

-16

-14

-12

-10

-8

-6

-4

-2

0

2

4

6

8

10

12

14

1000 1200 1400 1600 1800 2000 2200 2400 2600

Age (Ma)

Ep

silo

n H

f

Depleted Mantle

CHUR

Biranup

Zone

Mantle addition

Yilgarn Hf

0.01

0.1

1

10

100

1000

Rb Ba Th Nb Ta La Ce Pb Pr Sr Nd Zr Hf Sm Eu Ti Gd Tb Dy Ho Er Yb Lu

sample/standard

SEBZ 1690-1660 Ma granite

Madura Loongana 1410 Ma granite

Government of Western Australia Department of Mines and PetroleumGovernment of Western Australia Department of Mines and PetroleumGovernment of Western Australia Department of Mines and Petroleum

Sutures east of the Albany–Fraser

Orogen: Rodona Shear Zone?