Further development of a Precambrian plate model and its application in identifying sediment provenance

Bruce Eglington University of Saskatchewan

Overview

► Data available to aid model development ► Current status of model

Improvements to plate boundary delineation Meso- and Neo-Proterozoic and early

Palaeoproterozoic/Neoarchaean Better visualising different types of mineralisation Demo model

► Definition of Precambrian plates and relevance to Phanerozoic geology

► Additional constraints provided by detrital zircon provenance assessments

Overview

► Data available to aid model development ► Current status of model

Improvements to plate boundary delineation Meso- and Neo-Proterozoic and early

Palaeoproterozoic/Neoarchaean Better visualising different types of mineralisation Demo model

► Definition of Precambrian plates and relevance to Phanerozoic geology

► Additional constraints provided by detrital zircon provenance assessments

Geochronology

~ 106,000 records in the DateView geochronology database

Dyke swarms

~ 6,500 records in the StratDB LIP database, many with geospatial information in ArcMap compilation

Deposits

~ 15,000 deposit/mineralisation records in the StratDB database, most with latitude and longitude information. ~4,500 have Pb isotope data

Nd

T DM

Overview

► Data available to aid model development ► Current status of model

Improvements to plate boundary delineation Meso- and Neo-Proterozoic and early

Palaeoproterozoic/Neoarchaean Better visualising different types of mineralisation Demo model

► Definition of Precambrian plates and relevance to Phanerozoic geology

► Additional constraints provided by detrital zircon provenance assessments

Geophysical constraints

U-Pb Formation Ages

Nd TDM

Geographic extent of dated lithostratigraphic units

Interpreted maximum age of blocks

Overview

► Data available to aid model development ► Current status of model

Improvements to plate boundary delineation Plate motion constraints Meso- and Neo-Proterozoic and early

Palaeoproterozoic/Neoarchaean Better visualising different types of mineralisation Demo model

► Definition of Precambrian plates and relevance to Phanerozoic geology

► Additional constraints provided by detrital zircon provenance assessments

► Palaeomag constraints are primary – modelled using GPlates Paleogis plugin for ArcMap Customised software written by BE

Constraints for Palaeogeographic Reconstructions

► Palaeolongitude Estimated based on the orthoversion concept presented by

Mitchell and Evans (2012)

Most likely centroid of supercontinent

Constraints for Palaeogeographic Reconstructions

Palaeogeographic Reconstructions

► Extensive set of plates based on Geology Aeromagnetic and Gravity Anomalies

► Palaeomag constraints are primary – modelled using GPlates Paleogis plugin for ArcMap Customised software written by BE

► Consider structural vergence directions

Overview

► Data available to aid model development ► Current status of model

Improvements to plate boundary delineation Plate motion constraints Meso- and Neo-Proterozoic and early

Palaeoproterozoic/Neoarchaean Better visualising different types of mineralisation Demo model

► Definition of Precambrian plates and relevance to Phanerozoic geology

► Additional constraints provided by detrital zircon provenance assessments

Available Palaeogeographic Models

► Phanerozoic Paleomap (Chris Scotese) Earthbyte (GPlates) Various commercial models

► Meso- to Neo-Proterozoic IGCP 440 (Li et al., 2008) Various other ‘snap-shots’

► Palaeoproterozoic to Archaean Various, mostly schematic, ‘snap-

shots’ Eglington et al. (2013) Pisarevsky et al. (2013) Pehrsson et al. (2013)

Paleomap

IGCP 440

Rogers and Santosh, 2002 Zhao et al, 2002

Evans and Mitchell, 2011

Some available Palaeogeographic Reconstructions for Nuna (Columbia)

► Started with Palaeoproterozoic Nuna

► Working forward in time through Mesoproterozoic to Neoproterozoic Rodinia

► Also extending back towards Neoarchaean

Overview

► Data available to aid model development ► Current status of model

Improvements to plate boundary delineation Plate motion constraints Meso- and Neo-Proterozoic and early

Palaeoproterozoic/Neoarchaean Better visualising different types of mineralisation Demo model

► Definition of Precambrian plates and relevance to Phanerozoic geology

► Additional constraints provided by detrital zircon provenance assessments

Overview

► Data available to aid model development ► Current status of model

Improvements to plate boundary delineation Plate motion constraints Meso- and Neo-Proterozoic and early

Palaeoproterozoic/Neoarchaean Better visualising different types of mineralisation Demo model

► Definition of Precambrian plates and relevance to Phanerozoic geology

► Additional constraints provided by detrital zircon provenance assessments

Overview

► Data available to aid model development ► Current status of model

Improvements to plate boundary delineation Plate motion constraints Meso- and Neo-Proterozoic and early

Palaeoproterozoic/Neoarchaean Better visualising different types of mineralisation Demo model

► Definition of Precambrian plates and relevance to Phanerozoic geology

► Additional constraints provided by detrital zircon provenance assessments

Reconstruction at 1500 Ma Ages from 1500 – 1580 Ma

W. Australia

N. Australia

Gawler

Mawson

Siberia

Baltica

Amazonia

W. Africa

Superior

Slave

W. Gneiss Complex

VMS U Ni-Cu-PGE

Plutonic / volcanic crystallization

Cooling Metamorphic

Basement control of younger

sedimentation

From Paul Ramaekers (2011)

From Paul Ramaekers (2011)

Basement control of younger

sedimentation

From Paul Ramaekers (2011)

Basement control of younger

sedimentation

Basement control of younger

sedimentation

From Tankard et al (2009)

Basement control of younger

sedimentation

From Tankard et al (2009)

Basement control of younger

sedimentation

From Tankard et al (2009)

Basement control of younger

sedimentation

From Tankard et al (2009)

Overview

► Data available to aid model development ► Current status of model

Improvements to plate boundary delineation Plate motion constraints Meso- and Neo-Proterozoic and early

Palaeoproterozoic/Neoarchaean Better visualising different types of mineralisation Demo model

► Definition of Precambrian plates and relevance to Phanerozoic geology

► Additional constraints provided by detrital zircon provenance assessments

Pro

ba

bil

ity

Grain Age (Ma)

Un

it A

ge

(M

a)

Kaapvaal

3600

1200

1200 3800

1940 Ma

Neylan Fm

Lower Selika Formation

Pilbara

Zimbabwe

Kaapvaal

From Tankard et al (2009)

Detrital provenance

Detrital zircon age spectra for Cape and Karoo sediments

Detrital zircon age spectra for Cape and Karoo sediments

Detrital zircon age spectra for Cape and Karoo sediments

U-Pb Formation Ages

U-Pb Formation Ages

Cape-Karoo potential provenance sources 850 – 960 Ma

Detrital provenance

Acknowledgements ► IGCP 509 project ► University of Saskatchewan and NSERC

Databases housed at U of S

► Geological Survey of Canada Ore deposit information (especially via Lesley Chorlton) + various coworkers

► Various mining companies for student support and money to purchase hardware and software

Newmont Areva De Beers

► Paleogis plugin for ArcMap The Rothwell Group Chris Scotese

► GPlates software Dietmar Mueller and John Cannon in Sydney, Australia

► Various software companies for providing academic versions Embarcadero Steema AtoZed HK Systems