3D modelling of a turbidite-filled growth syncline from field data: the Annot syncline (SE France)

Lise Salles and Mary Ford and Christian Le Carlier de Veslud. ( 2008 )
in: 28th gOcad Meeting, ASGA

Abstract

The Annot Sandstone is a well-known analogue for sand-rich deep water reservoirs. It was deposited in a fan delta-fed turbidite setting over a period of 10My from the Bartonian to Rupelian, in the active alpine wedge top foreland basin. These turbidite deposits overlie the transgressive Nummulitic Limestone and deep water Globigerina Marls. The variety of facies, the difference in depositional patterns, and the superb exposures make this basin an ideal location to develop a methodology for 3D field-based modelling. The present model concerns the Annot depocentre, one of the synclinal remnants of the whole Annot Sandstone basin. Initially, the 1:50,000 geological map of stratigraphical boundaries and faults was draped over the Digital Elevation Model and combined with published data and some preliminary field data to produce a first 3D model of the base of the Nummulitic Limestone and the base of the Globigerina Marls. This model allowed us to identify specific geometrical problems for which the data was insufficient. A more detailed field study was undertaken to better constraint the structure. We particularly focus on the geometry of the overlying Annot Sandstone Formation. The present model includes 7 stratigraphical horizons within the Annot Sandstone, which are modeled based on detailed structural field data of onlaps and dips. The model demonstrates a progressive westward migration of the synclinal depocentre during the Annot Sandstone deposition. The details of this depocentre evolution are addressed using a 3D volumetric sequential restoration using a tetrahedral mesh. Mesh construction has to be adapted in the vicinity of onlap pinchouts.

Download / Links

    BibTeX Reference

    @inproceedings{SallesRM2008,
 abstract = { The Annot Sandstone is a well-known analogue for sand-rich deep water reservoirs. It was deposited in a fan delta-fed turbidite setting over a period of 10My from the Bartonian to Rupelian, in the active alpine wedge top foreland basin. These turbidite deposits overlie the transgressive Nummulitic Limestone and deep water Globigerina Marls. The variety of facies, the difference in depositional patterns, and the superb exposures make this basin an ideal location to develop a methodology for 3D field-based modelling. The present model concerns the Annot depocentre, one of the synclinal remnants of the whole Annot Sandstone basin. Initially, the 1:50,000 geological map of stratigraphical boundaries and faults was draped over the Digital Elevation Model and combined with published data and some preliminary field data to produce a first 3D model of the base of the Nummulitic Limestone and the base of the Globigerina Marls. This model allowed us to identify specific geometrical problems for which the data was insufficient. A more detailed field study was undertaken to better constraint the structure. We particularly focus on the geometry of the overlying Annot Sandstone Formation. The present model includes 7 stratigraphical horizons within the Annot Sandstone, which are modeled based on detailed structural field data of onlaps and dips. The model demonstrates a progressive westward migration of the synclinal depocentre during the Annot Sandstone deposition. The details of this depocentre evolution are addressed using a 3D volumetric sequential restoration using a tetrahedral mesh. Mesh construction has to be adapted in the vicinity of onlap pinchouts. },
 author = { Salles, Lise AND Ford, Mary AND Le Carlier de Veslud, Christian },
 booktitle = { 28th gOcad Meeting },
 month = { "may" },
 publisher = { ASGA },
 title = { 3D modelling of a turbidite-filled growth syncline from field data: the Annot syncline (SE France) },
 year = { 2008 }
}