Authors / CoAuthors
Clark, D.J.
Abstract
Many mapped faults in the south-eastern highlands of New South Wales and Victoria are associated with apparently youthful topographic ranges, suggesting that active faulting may have played a role in shaping the modern landscape. This has been demonstrated to be the case for the Lake George Fault, ~25 km east of Canberra. The age of fluvial gravels displaced across the fault indicates that relief generation of approximately 250 m has occurred in the last ca. 4 Myr. This data implies a large average slip rate by stable continental region standards (~90 m/Myr assuming a 45 degree dipping fault), and begs the question of whether other faults associated with relief in the region support comparable activity rates. Preliminary results on the age of strath terraces on the Murrumbidgee River proximal to the Murrumbidgee Fault are consistent with tens of metres of fault activity in the last ca. 200 kyr. Further south, significant thicknesses of river gravels are over-thrust by basement rocks across the Tawonga Fault and Khancoban-Yellow Bog Fault. While these sediments remain undated, prominent knick-points in the longitudinal profiles of streams crossing these faults suggest Quaternary activity commensurate with that on the Lake George Fault. More than a dozen nearby faults with similar relief are uncharacterised. Recent seismic hazard assessments for large infrastructure projects concluded that the extant paleoseismic information is insufficient to meaningfully characterise the hazard relating to regional faults in the south-eastern highlands, despite the potential for large earthquakes alluded to above. While fault locations and extents remain inconsistent across scales of geologic mapping, and active fault lengths and slip rates remain largely unquantified, the same conclusion may be drawn for other scales of seismic hazard assessment.
Product Type
document
eCat Id
113643
Contact for the resource
Point of contact for the resource
Point of contact
Cnr Jerrabomberra Ave and Hindmarsh Dr GPO Box 378
Canberra
ACT
2601
Australia
Point of contact
Keywords
- theme.ANZRC Fields of Research.rdf
-
- EARTH SCIENCES
- ( Theme )
-
- earthquake hazard
- ( Theme )
-
- hazard
-
- Published_External
Publication Date
2020-08-11T00:16:45
Creation Date
2017-09-05T00:00:00
Security Constraints
Classification - unclassified
Legal Constraints
Status
completed
Purpose
Australian Earthquake Engineering Society 2017 Meeting extended abstract
Maintenance Information
asNeeded
Topic Category
geoscientificInformation
Series Information
Lineage
final conference abstract
Parent Information
Extents
[-90.00, 90.00, -180.00, 180.00]
Reference System
Spatial Resolution
Service Information
Associations
Source Information