Integration of sedimentology and GPR for high-resolution imaging of a carbonate platform

Stéphan Jorry (1) , Grégory Bièvre (2, 3)

1 GM - Unité Géosciences Marines
2 LGIT - Laboratoire de Géophysique Interne et Tectonophysique
3 CETE de Lyon - Centre d'études techniques de l'équipement de Lyon

Ground-Penetrating Radar (GPR) has not been widely applied to the recognition of ancient carbonate platform geometries. This paper reports the results of an integrated study performed on an Upper Jurassic outcrop from the southeast Paris basin, where coral bioherms laterally change into prograding depositional sequences. GPR profiles illustrate the different bedding planes and major erosional unconformities visible at outcrop. A GPR profile conducted at the base of the cliff displays a palaeotopographic surface on which the outcropping bioherms settled. The excellent penetration depths of the GPR (20 meters with a monostatic 200 MHz antenna) images the carbonate platform geometries, ranging between outcrop workscale (some few meters) and seismic scale (several hundreds of meters). This study supports recent evidence of icehouse conditions and induced sea-level fluctuations controlling the Upper Jurassic carbonate production.

Mots clés: Paris Basin; late Jurassic; Ground-penetrating radar; Coral bioherms; Carbonate platform

Domaines: Géophysique [physics.geo-ph]; Milieux et Changements globaux; Géophysique [physics.geo-ph]; Stratigraphie

Stéphan Jorry, Grégory Bièvre. Integration of sedimentology and GPR for high-resolution imaging of a carbonate platform. 2009. ⟨insu-00442199⟩