Download - Lara Ramos
This project focuses on understanding the
Paleoproterozoic Bryah and Padbury Basins through
the interpretation of geophysical and geological
datasets, aiming to better understand the basins’
history and geological features, including architecture,
magmatism, sedimentary fill, and structural
development, as well as the mineralization controls.
www.cet.edu.au
Stratigraphy and Architecture of the Paleoproterozoic Bryah and Padbury Basins,
Capricorn Orogen: Towards an Understanding of Basin Evolution
Lara Ramos, Alan Aitken, Sandra Occhipinti, Mark Lindsay
CET-Centre for Exploration Targeting – The University of Western Australia
Thanks to Sandfire Resources and Metals X for allowing the drill core analysis at the DeGrussa
and Fortnum Mines, respectively, and for providing the samples for the petrophysical studies.
The first author thanks the CNPq-Brazilian Counsel of Technological and Scientific
Development for her scholarship, and thanks the Distal Footprints of Giant Ore System –
UNCOVER Australia (RP04-063) for project funding.
The Bryah Basin was formed in a rift setting along
the north margin of the Yilgarn Craton and contains
volcano-sedimentary rocks of the Bryah Group (c.
2018 Ma). The Padbury Basin comprises carbonate,
siliciclastic and banded iron formation rocks of the
Padbury Group (2000-1800 Ma) deposited over the
Bryah Group in a pro-foreland basin that developed
during the Glenburgh Orogeny (2005-1960 Ma)
Lower Bryah Group
Padbury GroupBryah Group
a.
b.
c.
Petrophysical data from the Bryah and Padbury Basins and the
surrounding terranes: a. summary of rock density plotted on a
stratigraphic column of the Bryah and Padbury Basins, and the
surrounding basement; b. magnetic susceptibility data; c. Box
plot of the Bouguer Anomaly values of the Bryah and Padbury
Basins’ units.
Bouguer anomaly over the TDR gravity image, with indications of major Boundaries
based on seismic data (Korsch & Doublier, 2016) and preliminary gravity features
interpretation. Note the relation of the VMS mineralization (e.g. DeGrussa Mine) with
the limits of the high gravity domain coincident with large faults.
Magnetic domains and preliminary magnetic structural interpretation defined based on the
magnetic amplitude and frequency of the Bryah and Padbury Basins and surrounding
terranes overlying the RTP image.
a. Bouguer anomaly slice filtered
according to the frequencies that indicate
deep gravity sources (~12km) interpreted
on the Power Spectrum (b).
a. Sourcing Parameters
Imaging (SPI) and Euler
deconvolution (index S0)
showing deeper magnetic
signals related with the
northern and southern
limits of the Bryah Basin,
b. Magnetic Power
Spectrum indicating
deeper magnetic sources
at ca. 4.5km, close to the
one indicated by the SPI
(4.25km).
B
b
a. Ternary Magnetic Image integrating 1DV, TDR and Theta
Map that individually proved useful during interpretation.
b. Geophysical structural interpretation over RTP image.
c. Field validation mapping.
a
c
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BRDD001 BRDD002 BRDD003
Preliminary graphic logs of the
Neptune Prospect.
Lower Padbury Sequence stratigraphy
column based on Martin (1998).
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DGDD347DDH1-F1
DGDD404
RCD358
Bryah and Padbury Basins geological map (Occhipinti et al,2017) over RTP image, and the stratigraphic columns of drill
holes from the Fortnum Mine (DDH1-F1), Horseshoe Lights (RCD358) and DeGrussa Mine (DGDD404 and DGDD3467).
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