Our best foot forward in new/old terrane: Delamerian Orogen progress Tom Wise
Our best foot forward in new/old terrane: Delamerian Orogen progress
Tom Wise
Project Aims
To stimulate mineral exploration beneath cover of the Murray Basin by providing industry with new data and new constraints on the geological framework and mineral prospectivity in this greenfields region.
Delamerian region had not been an area of focus for the GSSA for a couple (or more) decades. Association with the MinEx CRC National Drilling Initiative gave a platform.
Best foot forward
Data release Delamerian project
• Update of baseline geoscience datasets
• Stocktake atlas of geoscience data published – useful as a reference point pre- and post-National Drilling Initiative
• New data and ground acreage released 1st Sept
Legacy data entry
90 cored holes re-loggedGraphic lithological logs accompanied by descriptions of the main lithologies, their contact relationships, deformational fabrics, and alteration facies.
42 drill holes from the Sherlock Cu-Pb-Zn prospect and 6 drill holes from the Anabama Cu-Mo prospect have been scanned
Delamerian cover thickness and magnetic source depth modelling datasets
AusLAMP resistivity imaging the entire Curnamona Province and most of the onshore extent of the Delamerian Orogen
Primary questions to be addressed:How did the eastern Gondwanamargin evolve from the Proterozoic into the Phanerozoic?
• Was there subduction at any stage along the SA segment of the Gondwana margin?
• Is the SA segment fertile for subduction/post-subduction related porphyry Cu-Au/Mo deposits?
• What is the nature and age of the continental rift/rifted margin sediments beneath the Murray Basin?
• Do Cambrian sequences of the NSW Koonenberry Belt (prospective for VMS) continue into SA?
• What is the age and nature of magmatic/hydrothermal systems?
• What is the nature and thickness of cover and are cover sequences able to illuminate basement mineralisation?
Two regions identified to focus future work including drilling.
Northern Area:• Targeting continuation of Loch Lily Kars belt.
Possible unconformity suggests some units may be post-Delamerian. Test back-arc models. Porphyry-fertile ~400 Ma intrusions?
Southern Area• Targeting continuation of N-S trending volcano-
sedimentary belts including possible Cambrian arc segment and younger (Ordovician-Devonian?) mafic-intermediate intrusions
Drill planning
• Coiled Tubing rig• Fixed number of holes in
southern area first, more flexibility in the north
• Stick to basement <350m
• Chips through to fresh basement, then cored interval
surface
Basement unconformity
Weathered basement
Fresh basement = CORE (1.5+ m)
?
• Trade off between detail on individual target features and covering a wider region
• Transects with multiple holes in target features along and across strike
Drill planning
Quondong Vale – Northern area• ~20 drillholes planned, varying
priorities• Intersect as many different
lithologies as possible• Characterise continuation of Loch
Lily Kars Belt• Investigate possible unconformity
between basement units• Map cover architecture across
reactivated structures• Link to regional structure – MT and
gravity profile• Assess VMS & Porphyry potential
Alawoona – Southern area• Fixed drillhole locations, set
number• Map across multiple N-S belts• Assess porphyry potential• Investigate possible volcanic
arc segment, and belt along strike from Sherlock
• Intersect as many different lithologies as possible –volcanics/intrusives of different ages/host rock
• Map cover architecture across structures
• Link to regional structure
Thursday’s Gossan
Porphyry style system superimposed on serpentinised peridotite
Dismembered arc segments in the Stavely Zone, Western Vic.
Analagous to possible arc segments in the Alawoona area?
Revuelta, 2017
Skiagia ornataOakvale 1 drillholeEarly Cambrian age
Province-wide detrital zircon geochronology
40Ar/39Ar geochronology
MT section
Magmatism: Geochronology and Geochemistry
Loxton 2 greywacke3 episodes of
metasomatic regrowth at Anabama
courtesy L. Stoian
courtesy K. Robertson
courtesy Naina
courtesy S. Curtis
Anabama
Potential Collaboration/EFTF opportunities
Contact
Tom Wise, Senior Geologist
Department for Energy and Mining11 Waymouth StreetAdelaide, South Australia 5000GPO Box 320Adelaide, South Australia 5001T: +61 8 8429 2576E: [email protected]
Mineral Exploration Cooperative Research Centre
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