Abstract: Subsurface High Resolution Stratigraphy in the Jurassic of the Eastern Paris Basin
Alain Curial, Philippe Monier, Robert Moretto, Gilles Dromart, Alain Trouiller
The Jurassic of the eastern Paris basin is the stratigraphic record of three major Transgressive-Regressive cycles: Hettangian-Lowermost Aalenian; Aalenian-Middle Bathonian; Bathonian-Upper Oxfordian. The lower cycle is made up of shelf siliciclastic/carbonate depositional facies. The middle cycle corresponds to the initiation and climax of a skeletal/coral/ooidal carbonate platform. The upper cycle represents the drowning of the carbonate platform followed by a progressive re-colonization by carbonate shallow deposits.
2-D and 3-D stratigraphic architectures have been restored through a well-by-well, high resolution well-log correlation with reference to available sedimentologic and biostratigraphic data. The correlated packages represent genetic sequences and genetic-sequence sets.
The North-South cross-section connects the Ardennes Area with the Aube Area (200 km, 20 wells), and permits a number of points to be documented: (1) large stratal termination patterns (onlap, downlap, and toplap) associated with the major T-R cycles; (2) jumps through time of maxima of marine inundations because of tectonically-originated accommodation; (3) diachronism of regional lithostratigraphic units; (4) correlations of Vertical Stacking with Seaward or Landward Stepping patterns (5) syndepositional block-faulting.
The 3-D restoration has been realized in the Meuse and Haute-Marne Areas, with 34 wells investigated over an area of around 500 km2. The reconstruction has been focused on the Middle Callovian-Middle Oxfordian interval that is the record of a large carbonate platform progradation. Two major objectives have been addressed: measuring the enhancement of the stratigraphic architectural complexity through the progradational phase, discriminating the respective influence of the basin physiography (block-tilting/accommodation) and the carbonate factory (productivity) upon progradational patterns.
AAPG Search and Discovery Article #90956©1995 AAPG International Convention and Exposition Meeting, Nice, France