eCite Digital Repository

Crustal structure of southeast Australia from teleseismic receiver functions

Citation

Bello, M and Cornwall, DG and Rawlinson, N and Reading, AM and Likkason, OK, Crustal structure of southeast Australia from teleseismic receiver functions, Solid Earth, 12, (2) pp. 463-481. ISSN 1869-9510 (2021) [Refereed Article]


Preview
PDF
10Mb
  

Copyright Statement

Author(s) 2021. Licensed under Creative Commons Attribution 4.0 International (CC BY 4.0) https://creativecommons.org/licenses/by/4.0/

DOI: doi:10.5194/se-12-463-2021

Abstract

In an effort to improve our understanding of the seismic character of the crust beneath southeast Australia and how it relates to the tectonic evolution of the region, we analyse teleseismic earthquakes recorded by 24 temporary and 8 permanent broadband stations using the receiver function method. Due to the proximity of the temporary stations to Bass Strait, only 13 of these stations yielded usable receiver functions, whereas seven permanent stations produced receiver functions for subsequent analysis. Crustal thickness, bulk seismic velocity properties, and internal crustal structure of the southern Tasmanides - an assemblage of Palaeozoic accretionary orogens that occupy eastern Australia - are constrained by H- stacking and receiver function inversion, which point to the following: 1. a 39.0 km thick crust; an intermediate-high Vp=Vs ratio 1.70-1.76), relative to ak135; and a broad (>10 km) crust-mantle transition beneath the Lachlan Fold Belt. These results are interpreted to represent magmatic underplating of mafic materials at the base of the crust. 2. a complex crustal structure beneath VanDieland, a putative Precambrian continental fragment embedded in the southernmost Tasmanides, that features strong variability in the crustal thickness (23-37 km) and Vp=Vs ratio (1.65-193), the latter of which likely represents compositional variability and the presence of melt. The complex origins of VanDieland, which comprises multiple continental ribbons, coupled with recent failed rifting and intraplate volcanism, likely contributes to these observations. 3. stations located in the East Tasmania Terrane and eastern Bass Strait (ETTCEB) collectively indicate a crust of uniform thickness (31-32 km), which clearly distinguishes it from VanDieland to the west. Moho depths are also compared with the continent-wide AusMoho model in southeast Australia and are shown to be largely consistent, except in regions where AusMoho has few constraints (e.g. Flinders Island). A joint interpretation of the new results with ambient noise, teleseismic tomography, and teleseismic shear wave splitting anisotropy helps provide new insight into the way that the crust has been shaped by recent events, including failed rifting during the break-up of Australia and Antarctica and recent intraplate volcanism.

Item Details

Item Type:Refereed Article
Keywords:seismology, receiver functions, crustal structure
Research Division:Earth Sciences
Research Group:Geophysics
Research Field:Seismology and seismic exploration
Objective Division:Expanding Knowledge
Objective Group:Expanding knowledge
Objective Field:Expanding knowledge in the earth sciences
UTAS Author:Reading, AM (Professor Anya Reading)
ID Code:147929
Year Published:2021
Funding Support:Australian Research Council (LP110100256)
Web of Science® Times Cited:2
Deposited By:Physics
Deposited On:2021-11-24
Last Modified:2022-05-03
Downloads:2 View Download Statistics

Repository Staff Only: item control page