Eocene Calcareous Nannofossil Biostratigraphy from the Otway Basin, Australia

A sequence of biostratigraphic events from the middle to late Eocene, derived from calcareous nannofossil assemblages in four sections of southeastern Australia's Otway Basin. The dataset compares nannofossil and foraminiferal biostratigraphy, refining the placement of key foraminiferid events within tropical planktic zones. It provides evidence for diachronous marine sedimentation and changing environmental conditions along the Australian southern margin during this period.

Use Cases

• Refining biostratigraphic zonations based on the sequence of nannofossil events like the appearance of Cyclicargolithus reticulatus.
• Correlating regional stratigraphy by comparing the Otway Basin event sequence with its counterpart in New Zealand.
• Studying paleoenvironmental changes by analyzing evidence for temperate conditions, eastward-decreasing surface temperatures, and shallow marine deposition.
• Investigating sedimentation rates and hiatuses using data on condensed sections, disconformities, and expanded sediment packages.
• Assessing diachroneity in marine transgression events during the middle Eocene across the Gambier Embayment and Browns Creek areas.

Strengths

• Event sequence spans a defined geological interval from the middle to latest Eocene.
• Integrates two biostratigraphic methods by comparing nannofossil and foraminiferal data.
• Provides spatial context with data from four specific sections within the Otway Basin.
• Links local sedimentary events to broader tectonic processes like sea-floor spreading rate changes.

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/temporal bias inherent to the specific study sections in the Otway Basin.

Provenance

Source

Geoscience Australia Data

Collection Method

Study of calcareous nannofossil assemblages from four geological sections.

Time Range

Middle Eocene to latest Eocene

Freshness

Last updated 2026-04-30 13:27:29.831566; freshness should be verified.

Geography

Otway Basin, southeastern Australia, including the Gambier Embayment and Browns Creek area