Australian Tertiary Marine Bed Age Revisions Based on Microfossil Evidence

Drastic changes in the age classification of marine Tertiary deposits in Australia have occurred in recent years. The recognition of Eocene deposits across southeastern Australia resulted from detailed mapping in Victoria and microfaunal analysis of sediments. The discovery of the Eocene foraminiferal genus Hantkenina at sites like Bird Rock, Torquay, confirmed an Eocene age for beds previously classified as Upper Oligocene or Miocene.

Use Cases

• Re-evaluating stratigraphic timelines based on microfossil evidence like Hantkenina.
• Correlating marine deposit ages across southeastern Australian regions.
• Studying the transition between Eocene, Oligocene, and Miocene periods in Australia.

Strengths

• Describes a significant revision of geological age classifications based on fossil evidence.
• Cites specific fossil discoveries (Hantkenina) and locations (Bird Rock, Torquay, Anglesea).
• Mentions a proven thickness of at least 4,000 feet for Middle Eocene beds 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 on southeastern Australia.

Provenance

Source

Geoscience Australia Data

Collection Method

Detailed geological mapping and microfaunal investigation of sediments.

Time Range

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

Freshness

Last updated 2026-05-14 04:40:27.098042; freshness should be verified.

Geography

Australia, specifically southeastern regions including Victoria and the Adelaide Basin in South Australia.