Oldest Cretaceous Sequence in Giralia Anticline: Late Hauterivian-Barremian Stratigraphy

Geoscience Australia Data provides a detailed biostratigraphic assessment of the oldest Cretaceous sequence in the Giralia Anticline and Giralia No. 1 well. The description covers a 66-meter thick section comprising the Birdrong Sandstone and Muderong Shale, dated to the late Hauterivian-Barremian age. The record was last updated on 2026-04-20.

Use Cases

• Modeling transgressive systems tracts based on described sediment composition and biofacies changes.
• Analyzing paleoclimate signals based on growth-ring analysis of fossil conifer wood.
• Correlating regional sea-level rise events based on the described late Hauterivian-Barremian transgressive pulse.
• Studying fossil assemblages based on mentions of conifer wood, ichthyosauran bones, and ammonites.

Strengths

• Provides a detailed 66-meter stratigraphic column with specific unit thicknesses (e.g., 10 m Birdrong Sandstone, 56 m Muderong Shale).
• Includes biostratigraphic age assessment (Muderongia australis Zone, late Hauterivian-Barremian).
• Describes specific fossil content (conifer wood with Teredolites borings, ichthyosauran bones, ammonites).
• Offers paleoenvironmental interpretations (seasonal humid mesothermal climate, water depths less than 50 m).

Limitations

• Column-level documentation is absent; field semantics must be inferred after download.
• Row count is unknown, which may limit suitability assessment.
• The age of the upper Muderong Shale and a probable Windalia Sand Member is noted as uncertain.

Provenance

Source

Geoscience Australia Data

Collection Method

Outcrop and well description with biostratigraphic assessment.

Time Range

Late Hauterivian-Barremian (Early Cretaceous)

Freshness

Last updated 2026-04-20 00:53:04.689107; freshness should be verified.

Geography

Giralia Anticline, Carnarvon Basin, Western Australia