The Latrobe Group in the Gippsland Basin is a Late Cretaceous to Eocene aged clastic succession, which documents a period of syn- and post-rift deposition in southeastern Australia. During the breakup of Gondwana, rifting of the Australian continent from Antarctica provided accommodation space for the Latrobe Group coastal plain to marginal marine sediments to transgress across the Basin. These sediments provide both source and reservoir for hydrocarbons in the Gippsland Basin. Recent work on the Latrobe Group has indicated a greater marine influence than was previously interpreted; however this has not been described in detail. In addition to relative sea level rise, tectonics likely influenced depositional style; however this has not been documented in stratigraphic context. 3D seismic data, used in conjunction with well logs and core, provides a means for detailed interpretation of depositional features. Faults and horizons interpreted on the 3D seismic dataset form the basis of the stratigraphic framework, and aid in identifying tectonic influence. Correlating the seismic data to well logs provides geologic context, while core allows ‘ground-truthing’ of the seismic response. Thin section analysis and palynological data are incorporated to provide evidence of marine influence. This study provides much needed information on the sedimentology and tectonostratigraphy of the Latrobe Group, using modern data interpretation methods. A stratigraphic model will be developed, incorporating all data, focusing on qualifying marine and tectonic influence during deposition. This will provide greater understanding of Late Cretaceous syn-rift sedimentation in southeastern Australia, in addition to aiding with forward planning of a commercial producing basin.
AAPG Datapages/Search and Discovery Article #90351 © 2019 AAPG Foundation 2019 Grants-in-Aid Projects