Authors / CoAuthors
Marignier, A. | Eakin, C. M. | Hejrani, B. | Agrawal, S. | Hassan, R.
Abstract
<div>Around the world the Earth's crust is blanketed to various extents by sedimentary cover. For continental regions, knowledge of the distribution and thickness of sediments is crucial for a wide range of applications including seismic hazard, resource potential, and our ability to constrain the deeper crustal geology. Excellent constraints on the sedimentary thickness can be obtained from borehole drilling or active seismic surveys. However, these approaches are expensive and impractical in remote continental interiors such as central Australia. </div><div><br></div><div>Recently, a method for estimating the sedimentary thickness using passive seismic data, the collection of which is relatively simple and low-cost, was developed and applied to seismic stations in South Australia. This method uses receiver functions, specifically the time delay of the \P{}-to-\S{} converted phase generated at the sediment-basement interface, relative to the direct-P arrival, to generate a first order estimate of the thickness of sedimentary cover. In this work we expand the analysis to the vast array of over 1500 seismic stations across Australia, covering an entire continent and numerous sedimentary basins that span the entire range from Precambrian to present-day. We compare with an established yet separate method to estimate the sedimentary thickness, which utilises the autocorrelation of the radial receiver functions to ascertain the two-way travel-time of shear waves reverberating in a sedimentary layer.</div><div><br></div><div>Across the Australian continent the new results clearly match the broad pattern of expected sedimentation based on the various geological provinces. Furthermore we are able to delineate the boundaries of many sedimentary features, such as the Eucla and Murray Basins, which are Cenozoic, and the boundary between the Karumba Basin and the mineral rich Mount Isa Province. The signal is found to diminish for older Proterozoic basins, likely due to compaction and metamorphism of the sediments over time. Finally, a comparison with measurements of sedimentary thickness from local boreholes allows for a straightforward predictive relationship between the delay time and the cover thickness to be defined. This offers future widespread potential, providing a simple and cheap way to characterise the sedimentary thickness in under-explored areas from passive seismic data. </div><div><br></div><div>This study and some of the data used are funded and supported by the Australian Government's Exploring for the Future program led by Geoscience Australia.</div> <b>Citation:</b> Augustin Marignier, Caroline M Eakin, Babak Hejrani, Shubham Agrawal, Rakib Hassan, Sediment thickness across Australia from passive seismic methods, <i>Geophysical Journal International</i>, Volume 237, Issue 2, May 2024, Pages 849–861, <a href="https://doi.org/10.1093/gji/ggae070">https://doi.org/10.1093/gji/ggae070</a>
Product Type
document
eCat Id
149040
Contact for the resource
Resource provider
Point of contact
Cnr Jerrabomberra Ave and Hindmarsh Dr GPO Box 378
Canberra
ACT
2601
Australia
Point of contact
Keywords
- ( Project )
-
- Exploration For the Future - EFTF
- ( Project )
-
- Australia’s Resources Framework - ARF
-
- sedimentary cover
-
- passive seismic
-
- reciever functions
-
- Cover thickness
- theme.ANZRC Fields of Research.rdf
-
- Seismology and Seismic Exploration
-
- Published_External
Publication Date
2024-04-05T00:55:27
Creation Date
2023-11-04T20:00:00
Security Constraints
Legal Constraints
Status
completed
Purpose
Manuscript to be submitted to Geophysical Journal International.
Maintenance Information
notPlanned
Topic Category
geoscientificInformation
Series Information
Geophysical Journal International Volume 237, Issue 2, May 2024 849-861
Lineage
<div>A manuscript to be submitted to Geophysical Journal International. </div>
Parent Information
Extents
[-54.75, -9.2402, 112.92, 159.11]
Reference System
Spatial Resolution
Service Information
Associations
Source Information