OVERVIEW

An extensive Triassic review that delivers a major biostratigraphic upgrade for the Bonaparte Basin, reinterpreting over 600 samples across 26 wells with a consistent, high-resolution palynological framework.

This multi-client study yields crucial new insights into the regional stratigraphy of the Vulcan Sub Basin and adjacent areas of the Ashmore Platform and Londonderry High. In particular, the thick Carnian sequences present in the Vulcan Sub Basin were confidently subdivided by palynology for the first time, providing a better understanding of the timing of the Nome/Challis and Challis/Pollard formation boundaries.

BACKGROUND

As renewed interest in Triassic plays in the Bonaparte Basin continues to gather pace, the completion of a major biostratigraphic review by MGPalaeo aims to provide key stratigraphic support for your exploration needs.

The pre-existing Triassic palynology for much of the basin is a mix of old studies, broad zonal assignments, multiple zonation schemes and non-quantitative assemblage data. The newly revised palynological data provides a single, consistent set of zonal and subzonal assignments, thus allowing higher confidence well correlations and the construction of more robust sequence stratigraphic frameworks.

DETAILS

MGPalaeo has been able to apply its experience from other North West Shelf and Timor-Leste Triassic plays, including much of the higher resolution Carnian–Rhaetian biostratigraphy developed in the Northern Carnarvon Basin, to this study.

26 wells were selected for review, with particular emphasis on the Vulcan Sub Basin and adjacent areas of the Ashmore Platform and Londonderry High. More than 600 Triassic palynology samples were reanalysed in full, with quick-look revisions added for a further 50 samples. The existing datasets from the key outboard Ashmore Platform wells (Ashmore Reef 1, Mt Ashmore 1 and North Hibernia 1) were also reviewed as they contain thicker Norian successions.

Table 1: Wells selected for each phase of this study.

Phase 1Phase 2Data Review
Brown Gannet 1Dillon Shoals 1Ashmore Reef 1
Cassina 2Halcyon 1Mt Ashmore 1
Crane 1Maple 2North Hibernia 1
Great Auk 1Rainbow 1
Osprey 1Rainier 1
Pengana 1Sebring 1
Pokolbin 1Snowmass 1
Pollard 1Talbot 1
Sahul Shoals 1Troubadour 1
Saucepan 1Turnstone 1
Warb 1AWoodbine 1
Yarra 1

OUTCOMES

The review has yielded crucial new insights into the regional stratigraphy, with significant revisions to the palynological zonal and subzonal assignments, and consequently to the lithostratigraphic and sequence stratigraphic interpretations.

In particular, the thick Carnian sequences present in the Vulcan Sub Basin were confidently subdivided by palynology for the first time, providing a better understanding of the timing of the Nome/Challis and Challis/Pollard formation boundaries.

DELIVERABLES

  1. Tabulated biostratigraphic data, fully revised and updated
  2. Interpretative Stratabugs Chart, including full quantitative assemblage counts
  3. Summary report

Additional data available through the AUSTRALIS database

  1. Revised litho- and sequence picks
  2. Geophysical logs, geochem, deviation and checkshot surveys, etc
  3. Well correlation panels

For more information on this multi-client study, please contact us.