Authors / CoAuthors
Magee, J.W. | Gibson, D.L. | Clarke, J.D.A. | Lawrie, K. | Halas, L.
Abstract
This study was undertaken to establish a chronology for Quaternary fluvial landscape in the Darling River floodplain area. This was required to constrain the 3D mapping of floodplain units and to constrain conceptual models of surface-groundwater interaction. The lower Darling Valley contains Cenozoic shallow marine, fluvial, lacustrine and aeolian sediments including a number of previously poorly dated Quaternary fluvial units associated with the Darling River and its anabranches. New geomorphic mapping of the Darling floodplain that utilises a high-resolution LiDAR dataset and SPOT imagery, has revealed that the Late Quaternary sequence consists of scroll-plain tracts of different ages incised into a higher more featureless mud-dominated floodplain. Furthermore, the Understanding the relationships between these geomorphic units Samples for OSL (Optically-Stimulated Luminescence) and radiocarbon dating were taken in tractor-excavated pits, from sonic drill cores and from hand-auger holes from a number of scroll-plain and older floodplain sediments in the Menindee region. The youngest, now inactive, scroll-plain phase, associated with the modern Darling River, was active in the period 5-2 ka. A previous anabranch scroll-plain phase has dates around 20 ka. Indistinct scroll-plain tracts older than the anabranch system, are evident both upstream and downstream of Menindee and have ages around 30 ka. These three scroll-plain tracts intersect just south of Menindee but are mostly separated upstream and downstream of that point. Older dates of 50 ka, 85 ka and >150 ka have been obtained from lateral-migration sediments present beneath the higher mud-dominated floodplain. Age dating of the Quaternary fluvial sediments has been used to constrain a model of landscape evolution, neotectonics and recharge dynamics. Geomorphic and structural mapping identified a number of structural lineaments in the LiDAR data. These structures are coincident with mapped faults at depth in airborne electromagnetic (AEM) and airborne magnetic (and gravity) data. Those faults mapped at surface have varying landscape expression, with many re-worked by younger scroll-plain tracts. Younger faults appear to play a role in surface-groundwater interaction, while older faults are important for inter-aquifer leakage.
Product Type
nonGeographicDataset
eCat Id
75758
Contact for the resource
Custodian
Owner
Custodian
Cnr Jerrabomberra Ave and Hindmarsh Dr GPO Box 378
Canberra
ACT
2601
Australia
Keywords
-
- External PublicationAbstract
- Australian and New Zealand Standard Research Classification (ANZSRC)
-
- Geology
-
- Published_Internal
Publication Date
2013-01-01T00:00:00
Creation Date
Security Constraints
Legal Constraints
Special, MOU, etc.
Access - restricted
Use - license
Status
Purpose
Maintenance Information
notPlanned
Topic Category
geoscientificInformation
Series Information
Lineage
Abstract prepared for submission to the International Association of Hydrogeologists (IAH).
Parent Information
Extents
Reference System
Spatial Resolution
Service Information
Associations
Downloads and Links
Source Information
Source data not available.