A geological report from Geoscience Australia analyzing subsurface permeability barriers affecting groundwater flow in the Murray Basin. The paper describes the stratigraphy and geometry of mid-Tertiary units, including the Ettrick Formation, Winnambool Formation, and Geera Clay, based on borelog analysis and palaeogeographic reconstructions. It includes specific porosity and permeability data from a fully cored section in the Piangil West-2 borehole.
Use Cases
- Modeling groundwater flow paths based on described subsurface permeability barriers.
- Assessing the impact of the Geera Clay barrier on surface discharge of saline groundwater.
- Reconstructing palaeogeographic marine incursions into the Murray Basin during the Cainozoic.
- Estimating aquifer connectivity based on the stratigraphy and distribution of confining layers.
Strengths
- Provides specific porosity estimates for the Geera Clay, ranging from 0-7% effective porosity.
- Describes detailed lithological composition from a fully cored borehole section.
- Offers a temporal framework for marine incursions, with one event lasting at least 20 million years.
Limitations
- Description metadata is limited; actual data quality requires manual inspection after download.
- Column-level documentation is absent; field semantics must be inferred after download.
- Row count is unknown, which may limit suitability assessment.
Provenance
- Source
- Geoscience Australia Data
- Collection Method
- Subsurface facies analysis of borelogs and palaeogeographic reconstructions.
- Time Range
- Mid-Tertiary (Oligocene to Miocene), with specific events dated to about 32 million years ago.
- Freshness
- Last updated 2026-05-14 09:42:07.940828; freshness should be verified.
- Geography
- Murray Basin, southeastern Australia.