Cardiff University | Prifysgol Caerdydd ORCA
Online Research @ Cardiff 
WelshClear Cookie - decide language by browser settings

Formation of cratonic lithosphere during the initiation of plate tectonics

Beall, A.P., Moresi, L. and Cooper, C.M. 2018. Formation of cratonic lithosphere during the initiation of plate tectonics. Geology 46 (6) , pp. 487-490. 10.1130/G39943.1

[thumbnail of Beall_2018_CratonFormation_Geology_Preprint.pdf]
Preview
PDF - Accepted Post-Print Version
Download (310kB) | Preview

Abstract

Earth’s oldest near-surface material, the cratonic crust, is typically underlain by thick lithosphere (>200 km) of Archean age. This cratonic lithosphere likely thickened in a high-compressional-stress environment, potentially linked to the onset of crustal shortening in the Neoarchean. Mantle convection in the hotter Archean Earth would have imparted relatively low stresses on the lithosphere, whether or not plate tectonics was operating, so a high stress signal from the early Earth is paradoxical. We propose that a rapid transition from heat pipe–mode convection to the onset of plate tectonics generated the high stresses required to thicken the cratonic lithosphere. Numerical calculations are used to demonstrate that an existing buoyant and strong layer, representing depleted continental lithosphere, can thicken and stabilize during a lid-breaking event. The peak compressional stress experienced by the lithosphere is 3×–4× higher than for the stagnant-lid or mobile-lid regimes immediately before and after. It is plausible that the cratonic lithosphere has not been subjected to this high stress state since, explaining its long-term stability. The lid-breaking thickening event reproduces features observed in typical Neoarchean cratons, such as lithospheric seismological reflectors and the formation of thrust faults. Paleoarchean “pre-tectonic” structures can also survive the lid-breaking event, acting as strong rafts that are assembled during the compressive event. Together, the results indicate that the signature of a catastrophic switch from a stagnant-lid Earth to the initiation of plate tectonics has been captured and preserved in the characteristics of cratonic crust and lithosphere.

Item Type: Article
Date Type: Publication
Status: Published
Schools: Earth and Environmental Sciences
Publisher: Geological Society of America
ISSN: 0091-7613
Date of First Compliant Deposit: 11 October 2018
Date of Acceptance: 18 March 2018
Last Modified: 08 Nov 2023 03:10
URI: https://orca.cardiff.ac.uk/id/eprint/115763

Citation Data

Cited 31 times in Scopus. View in Scopus. Powered By Scopus® Data

Actions (repository staff only)

Edit Item Edit Item

Downloads

Downloads per month over past year

View more statistics