Australian Tertiary Marine Bed Age Revisions Based on Microfossil Evidence

Australian marine Tertiary deposits have undergone significant age reassessments in recent years. The dataset, sourced from the Australian Ocean Data Network, details the recognition of Eocene deposits across southeastern Australia, driven by detailed mapping and microfaunal analysis. Key discoveries include the foraminiferal genus Hantkenina at sites like Bird Rock, Torquay, which reclassified beds from Upper Oligocene/Miocene to Eocene.

Use Cases

• Re-evaluating regional stratigraphic correlations based on revised age assignments for key stages like the Janjukian.
• Studying the distribution and significance of the Eocene foraminiferal genus Hantkenina in the Southern Hemisphere.
• Analyzing the thickness and extent of Middle Eocene sequences, referenced as being over 4,000 feet thick in bore data.
• Investigating the potential existence of Lower Eocene to Paleocene beds in western Victoria as suggested in the description.
• Comparing age interpretations for non-marine deposits, which shifted from Lower Oligocene to Middle Miocene.

Strengths

• Describes a significant revision of geological age concepts based on detailed mapping and microfaunal investigation.
• Cites specific, impactful fossil discoveries, such as Hantkenina at Bird Rock, Torquay.
• Provides concrete stratigraphic relationships, noting that beds at Anglesea underlie those at Torquay.
• References a quantified thickness for Middle Eocene beds, stated as "at least 4,000 feet" proven in bores.

Limitations

• Column-level documentation is absent; field semantics must be inferred after download.
• Row count is unknown, which may limit suitability assessment.
• Data may reflect geographic bias inherent to data_gov_au, focusing primarily on southeastern Australia.

Provenance

Source

Australian Ocean Data Network

Collection Method

Likely compiled from geological surveys, borehole data, and paleontological studies.

Time Range

Tertiary period (Paleocene to Pliocene), with a focus on Eocene reclassifications.

Freshness

Last updated 2026-06-27 21:34:22.371383; freshness should be verified.

Geography

Southeastern Australia, specifically Victoria (Torquay, Anglesea), South Australia (Adelaide Basin), and western Victoria.