Mesozoic Rock Petrography from Exmouth Plateau Dredging

Dredging along seismic profiles in water 2000-5600 meters deep recovered geological samples from the northern Exmouth Plateau margin. The analysis defined seven major lithofacies associations and 14 microfacies types of shallow water carbonates from the Late Triassic to Callovian period. This work was conducted by researchers aboard the R.V. Sonne and R.V. Rig Seismic and published by the Australian Ocean Data Network.

Use Cases

• Correlating Late Triassic-Callovian carbonate microfacies with coeval platform deposits in the Alps and Mediterranean region.
• Analyzing the transition from shallow-subtidal carbonates to hemipelagic micrites and calcarenitic turbidites during latest Triassic subsidence.
• Studying the diagenetic transformations involving silica, silicates, carbonates, and phosphates in uplifted blocks like the Wombat Plateau horst.
• Reconstructing the post-breakup depositional history from Lower Cretaceous marginal-marine claystone to Late Cretaceous eupelagic chalks.
• Identifying lithofacies associations such as coal measures and their weathered ironstone products to understand Jurassic uplift and erosion.

Strengths

• Analysis defines 7 distinct lithofacies associations and 14 microfacies types.
• Samples collected from a significant depth range of 2000 to 5600 meters.
• Enables correlation with coeval Tethyan platform carbonates in Europe.

Limitations

• Specific sample counts, row counts, and quantitative measurements are not provided.
• Data is presented as a descriptive geological analysis rather than a structured, machine-readable table.
• Temporal coverage is broad (Late Triassic to Cainozoic) but sample resolution within that range is unspecified.

Provenance

Source

Australian Ocean Data Network

Collection Method

Rock samples dredged from the seafloor along seismic reflection profiles by research vessels R.V. Sonne (Cruise SO-8) and R.V. Rig Seismic (BMR Cruise 56).

Time Range

Late Triassic to Cainozoic (approximately 230 to 0 million years ago), with detailed focus on Late Triassic to Middle Jurassic.

Freshness

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Geography

Northern margin of the Exmouth Plateau, offshore Western Australia, southeastern margin of the Tethys Ocean.