Basement and crustal results from the Bremer Sub-basin, SW Australia and its Antarctic cou

Geoscience Australia's 2004 Southwest Frontiers Survey acquired 2700 km of industry-standard seismic data to study the continental margin. One key finding is that basement velocities are in the 5.2-5.6 km/s range, indicating a composition that is likely not granitic. Results from a conjugate site in Antarctica, obtained by a Russian expedition in 2004-2005, show consistent low velocities, suggesting a ~400km wide zone in the pre-breakup Gondwana supercontinent.

Use Cases

• Improving depth conversion of reflection seismic data based on accurate seismic velocity information.
• Modeling tectonic evolution of the region based on estimates of crustal thickness under sediment deposition centers.
• Re-evaluating hydrocarbon maturation scenarios based on the finding that basement metasediments produce less heat than granite.
• Correlating basement composition and structure between conjugate margins based on consistent low-velocity results from Australia and Antarctica.

Strengths

• Survey acquired 2700 km of 106-fold seismic data recorded to 12 seconds two-way time.
• Refraction data supplemented by sonobuoy and land station recordings, substantially improving area coverage.
• Velocity data indicate a maximum sediment thickness in excess of 9 km.
• Findings are supported by correlative data from a Russian Antarctic Expedition.

Limitations

• Column-level documentation is absent; field semantics must be inferred after download.
• Row count is unknown, which may limit suitability assessment.
• Last updated 2026-04-30 13:09:03.050000; freshness should be verified.

Provenance

Source

Geoscience Australia Data

Collection Method

Marine reflection and refraction seismic survey using a 6-8 km digital streamer and 4900 cui gun array, supplemented by sonobuoy and land station recordings.

Time Range

Survey conducted in late 2004; correlative Antarctic data from December 2004 - April 2005.

Freshness

Last updated 2026-04-30 13:09:03.050000

Geography

South-western Australian continental margin (Bremer Sub-basin) and its conjugate counterpart in Antarctica.