Authors / CoAuthors
Nayak, G.K. | Morse, M.P. | Gibson, G.M. | Stacey, A.R. | Mitchell, C.H.
Abstract
Deep-water Otway and Sorell basins developed during Gondwana break-up when Australia rifted away from Antarctica. The 2D and 3D gravity modelling in conjunction with seismic and geological interpretation has led us to an improved understanding of basement architecture of the study area. 2D gravity modelling particularly along selected seismic lines reveals a N-S crustal-scale lineament extending down to the Moho. A distinct density contrast of 0.16 t/m3 (3.05 t/m3 and 2.89 t/m3) across the structure points to a significant lithological difference at middle to lower crustal depths, interpreted here to reflect a change from dominantly basaltic to felsic lower crust. This structure is assumed to be inherited from a pre-existing basement structure and supports the hypothesis that the evolution of the Sorell Basin was probably basement controlled. The 2D models also help us to conclude the basaltic underplating in the lower-crustal region resulting from the breakup history, all long the margin. The computed 3D gravitational response of the basin-wide seismic interpretation correlates moderately well to the observed gravity trend, which implies (a) consistency between the seismic and gravity data of the inferred model. (b) Throws some light on basement topography, hence gives an idea of possible depo-centres. The depth to magnetic basement map derived independently from magnetic data has given a close proximity with that obtained from the 3D forward modelling, which essentially enhance reliability on the derived model to a good extent.
Product Type
nonGeographicDataset
eCat Id
70275
Contact for the resource
Custodian
Owner
Point of contact
Cnr Jerrabomberra Ave and Hindmarsh Dr GPO Box 378
Canberra
ACT
2601
Australia
Keywords
-
- External PublicationConference Paper
- ( Theme )
-
- 3D model
- ( Theme )
-
- magnetics
- ( Theme )
-
- gravity
- Australian and New Zealand Standard Research Classification (ANZSRC)
-
- Gravimetrics
-
- Published_Internal
Publication Date
2010-01-01T00:00:00
Creation Date
Security Constraints
Legal Constraints
Status
Purpose
Maintenance Information
unknown
Topic Category
geoscientificInformation
Series Information
Lineage
Unknown
Parent Information
Extents
[-42.0, -38.0, 140.5, 145.5]
Reference System
Spatial Resolution
Service Information
Associations
Source Information
Source data not available.