Leg 189 Synthesis: Cretaceous-Holocene History of the Tasmanian Gateway

4539 meters of marine sediment core were recovered from five sites in the Tasmanian Gateway, with an 89% recovery rate. The data, synthesized by the Australian Ocean Data Network, documents the region's transition from shallow marine mudstones to pelagic carbonates, capturing the opening of the gateway and its climatic impact. The sequence spans from the upper Maastrichtian to the Holocene, providing a continuous record of one of the Cenozoic's major climatic shifts.

Use Cases

• Modeling the timing and climatic effects of the Tasmanian Gateway opening based on sediment type transitions described.
• Analyzing microfossil assemblages (palynomorphs, diatoms, nannofossils, foraminifers) for paleoenvironmental reconstruction.
• Correlating sedimentological changes (e.g., glauconitic siltstones, unconformities) with tectonic and oceanographic events.
• Investigating the link between gateway opening, Antarctic thermal isolation, and ice sheet development described in the hypothesis.

Strengths

• 4539 meters of largely continuous core material provides a substantial physical record.
• An 89% core recovery rate suggests a high-quality, relatively complete sampling.
• The description details a clear temporal sequence from the Late Cretaceous to the Holocene with specific sediment types.

Limitations

• Column-level documentation is absent; field semantics must be inferred after download.
• Row count is unknown, which may limit suitability assessment for quantitative analysis.
• The primary file format is HTML, which may not be structured for direct machine analysis.

Provenance

Source

Australian Ocean Data Network, synthesizing Ocean Drilling Program (ODP) Leg 189 data.

Collection Method

Scientific ocean drilling and core analysis.

Time Range

Upper Maastrichtian to Holocene (approximately Late Cretaceous to present).

Freshness

Last updated 2026-04-10 18:46:43.621358; freshness should be verified.

Geography

Bathyal depths on submerged continental blocks in the Tasmanian Gateway, Southern Ocean.