Eumeralla Formation: Cretaceous Rift Basin Lithostratigraphy

Early Cretaceous non-marine volcaniclastic sediments in Australia's Otway Basin record the break-up of eastern Gondwana. Wireline-log and sedimentary data discriminate four informal lithostratigraphic units, interpreted as representing environments from coal swamps to high-energy stream channels. The basin-wide extent of three lower units suggests a single, integrated drainage system persisted at least until the late Albian.

Use Cases

• Reconstructing paleo-drainage systems based on basin-wide lithostratigraphic correlations.
• Analyzing sedimentary facies to interpret depositional environments like coal swamps and flood plains.
• Correlating lithology and depositional environment changes with Aptian-Albian sea-level fluctuations.
• Investigating the influence of intrabasinal volcanism on sedimentation patterns and basin drainage.

Strengths

• Analysis is based on wireline-log data and a range of sedimentary data, providing multiple lines of evidence.
• Sedimentary facies analysis of outcropping units (Eumeralla II and III) confirms environmental interpretations.
• Identifies four distinct lithostratigraphic units with specific rock type compositions across the Otway Basin.

Limitations

• Dataset size, row count, and specific column schema are unknown, limiting direct usability.
• Metadata for license, author, and precise data collection method is absent from all sources.
• The bases of the four lithostratigraphic units are described as probably diachronous, introducing temporal uncertainty.

Provenance

Source

Australian Ocean Data Network

Collection Method

Wireline-log analysis and sedimentary facies analysis of outcrops.

Time Range

Early Cretaceous (Aptian to Albian stages)

Freshness

Last updated metadata indicates 2026-06-27, though this appears to be a future date which may be a system error.

Geography

Otway Basin, southern margin of Australia (covers parts of VIC, SA, TAS, WA, NSW)