Slow Seafloor Spreading Patterns Off Southern Australia, 96-44.5 Ma

Geoscience Australia Data compiled seafloor spreading magnetic data for the southern margin of Australia. The dataset documents the pattern of slow spreading (<4 mm/year) from continental breakup at 96 million years ago (Ma) to A20 time (44.5 Ma). It includes critical data from the 1986 R/V Rig Seismic cruise and confirms previous work with a re-interpretation of the oldest magnetic anomalies.

Use Cases

• Modeling plate tectonic separation rates based on documented half-rates of <4.4 mm/year, 10 mm/year, and 20 mm/year.
• Analyzing spreading ridge jumps between 131.25° E and Tasmania mentioned in the description.
• Studying the relationship between separation azimuth (335°) and variable spreading isochron azimuths (e.g., 090°±5°, 075°-080°).
• Comparing slow spreading system responses to oblique continental margins, as analogously described for the Gulf of Aden.

Strengths

• Includes critical data from a specific research cruise (R/V Rig Seismic, 1986).
• Describes a clear temporal sequence of spreading phases from 96 Ma to 44.5 Ma.
• Provides specific numerical rates (e.g., half-rate <4.4 mm/year) and azimuths (335°).

Limitations

• Column-level documentation is absent; field semantics must be inferred after download.
• Row count is unknown, which may limit suitability assessment.
• Data formats are PDF and HTML, which may require extraction for computational analysis.

Provenance

Source

Geoscience Australia Data

Collection Method

Compilation of seafloor spreading magnetic data, including shipborne survey data.

Time Range

Covers geological time from >160 Ma (mid-Jurassic) to present, with focus on 96 Ma to 44.5 Ma.

Freshness

Last updated 2026-03 18:13:42.433654; freshness should be verified.

Geography

Southern margin of Australia, specifically between 129° E and 131.75° E, and the separation zone between Australia/Tasmania and Antarctica.