Distribution of coral-microbialite reefs along the French Jura platform during the Bimammatum Zone (Oxfordian, Late Jurassic)

Abstract

In the Late Jurassic, carbonate platforms and reefs were widespread in the various known geographical realms, north Tethysian, south Tethysian, north Atlantic, and Pacific (Leinfelder 2001). The many studies conducted by R. Leinfelderʼs German team during the 1990s have shown that these reefs were diversified and occupied specific ecological niches: stromatolites near the shore line, coral reefs in relatively shallow and proximal zones, siliceous sponge bioherms in deeper and distal parts of the platform, and microbial mounds in deep epicontinental

Development of coral–sponge–microbialite reefs in a coated grain-dominated carbonate ramp (Upper Jurassic, eastern Sardinia, Italy)

“…On the western margin of the Iberian Basin during the Kimmeridgian (Aurell et al 2003;Alnazghah et al 2013), pinnacle reefs are reported in the middle ramp (San Miguel et al 2017), with similar composition but different geometry with respect to the type 2 lens-shaped build-ups of eastern Sardinia. Carbonate ramps with ooidal shoals in the inner ramp and coral-microbial reefs in middle-ramp environment are reported from the Oxfordian of the French Jura and Paris Basin (Burgundy, Armorican and Lorraine platforms), where an epicontinental sea flooded the area among scattered emerged lands (Bertling and Insalaco 1998;Lathuilière et al 2005;Olivier et al 2011;Brigaud et al 2014;Olivier 2019).…”