Authors / CoAuthors
Holzschuh, J. | McAlpine, S.R.B. | Nicholl, M.
Abstract
The Coompana Project is a collaborative project between Geoscience Australia and the Geological Survey of South Australia, co-funded by Geoscience Australia’s Exploring for the Future Programme and the South Australian Government’s PACE Copper Initiative. The Coompana Project aims to provide new precompetitive geological, geophysical and geochemical data in the under-explored Coompana Province in South Australia. The pre-drilling geophysics program was undertaken to assist the drilling process by reducing the uncertainty associated with intersecting the targeted stratigraphy. Seismic data were acquired at eight proposed drilling sites for the Coompana Drilling Program in February 2017. Seismic data were collected using vertical and horizontal geophones. An accelerated weight-drop source was tested with metal and plastic strike plates. The plastic strike plate was preferred and used for all sites. P-wave reflection images were used to images subsurface layers and estimate bedrock depth at each drill site. Horizontal geophone data indicated S-wave data had higher resolution than the vertical geophone P-wave data, but initial testing did not provide good bedrock imaging. Fan shots can indicate zones of low velocity weathering at the near surface. Multichannel Analysis of Surface Waves provided near surface weathering profiles. Near surface weathering can be an indication of caves in this limestone environment. The S-wave shot records may indicate the presence of caves with S-wave signal degradation at cave locations, as S-waves do not travel through voids, not noticed at these sites. The seismic reflection method can be used to show subsurface variations and provide bedrock depth estimates, though the bedrock can be difficult to identify. The data is very noisy and data quality changes at different locations. Seismic data quality can be improved with a higher energy source.
Product Type
document
eCat Id
115081
Contact for the resource
Point of contact
Text
Point of contact
Cnr Jerrabomberra Ave and Hindmarsh Dr GPO Box 378
Canberra
ACT
2601
Australia
Digital Object Identifier
Keywords
- ( Theme )
-
- seismic reflection
- ( Theme )
-
- S-wave
- ( Theme )
-
- P-Wave
- ( Theme )
-
- MASW
- ( Theme )
-
- cavity detection
- ( Theme )
-
- depth to bedrock
- ( Theme )
-
- Coompana Province, South Australia
- ( Theme )
-
- subsurface imaging
- ( Theme )
-
- fan shooting
- ( Theme )
-
- seismic data acquisition
- ( Theme )
-
- seismic data processing
- ( Theme )
-
- carbonates
- ( Theme )
-
- limestone
-
- Published_External
Publication Date
2018-05-31T04:00:21
Creation Date
2017-11-10T00:00:00
Security Constraints
Legal Constraints
Status
Purpose
Accelerated weight drop seismic reflection data were used to image the subsurface to assist the drilling program. Cave identification is attempted.
Maintenance Information
asNeeded
Topic Category
geoscientificInformation
Series Information
Lineage
Seismic data were acquired at eight proposed drilling sites for the Coompana Drilling Program in February 2017. Seismic data were collected using vertical and horizontal geophones. An accelerated weight-drop source was tested with metal and plastic strike plates and plastic plate preferred. Data were processed from March to May 2017. P-wave reflection imaged subsurface layers and depth converted images were used to approximate depth to bedrock. Fan shots, MASW models and S-wave data were examined to identify subsurface caves if they exist.
Parent Information
Extents
[-31.7, -30.7, 129, 130]
Reference System
Spatial Resolution
Service Information
Associations
Downloads and Links
Source Information