Mid-Tertiary Permeability Barriers in the Murray Basin, Southeastern Australia

32 million years ago, a shallow sea invaded the western Murray Basin, initiating a marine incursion that lasted at least 20 million years. This dataset, from the Australian Ocean Data Network, is a geological paper summarizing the stratigraphy and geometry of subsurface units that form major permeability barriers affecting groundwater flow. The analysis is based on subsurface facies from borelogs and palaeogeographic reconstructions, with specific porosity data from the Piangil West-2 borehole.

Use Cases

• Model groundwater flow disruption based on the described arcuate low-permeability barrier formed by the Winnambool Formation and Geera Clay.
• Analyze aquifer geometry and confining layers based on the stratigraphic relationships between the Renmark Group, Ettrick Formation, and Murray Group.
• Assess subsurface porosity and permeability based on the detailed lithological breakdown from the Piangil West-2 borehole core.
• Reconstruct palaeogeographic marine incursions based on the described three separate Cainozoic sea invasions of the basin.

Strengths

• Provides specific porosity estimates (0-7% effective, 5-10% original) from a fully cored borehole section.
• Includes detailed lithological percentages (6% clay, 65% silt, 15% sand, 14% mud) for the Geera Clay formation.
• Describes temporal coverage of major geological events, including a marine incursion lasting at least 20 million years starting ~32 Ma.

Limitations

• Column-level documentation is absent; field semantics must be inferred after download.
• Row count is unknown, which may limit suitability assessment.
• Data is presented as a PDF/HTML paper, requiring extraction for computational analysis.

Provenance

Source

Australian Ocean Data Network

Collection Method

Subsurface facies analysis of borelogs and palaeogeographic reconstructions.

Time Range

Mid-Tertiary (Oligocene-Miocene), with events spanning from approximately 32 million years ago.

Freshness

Last updated 2026-04-10 18:50:15.717894; freshness should be verified.

Geography

Subsurface of the Murray Basin, southeastern Australia, with focus on west-central areas.