The shifting biogeography of reef corals during the Oxfordian (Late Jurassic). A climatic control?

International audienceUntil recently, the Jurassic was thought to have been a period characterised by a predominantly warm and equable climate. During the Oxfordian (a time span of six million years in the Late Jurassic) the distribution of tropical coral reefs was limited to about 35°N and near to 25°S. However, in Middle Oxfordian time, coral reefs were abundant only at higher latitudes and almost entirely missing near the equator. During that time the area of maximum reef development had shifted poleward to a belt lying between 20°N and 35°N, leaving hardly any coral formations at the lower inner-tropical latitudes. After demise towards the end of Middle Oxfordian time, the low-latitude reefs recovered during the Late Oxfordian, accompanied by a southward migration of reef corals in the northern hemisphere. As suggested by stable isotope and palynological data, the faunal migration can be correlated with a significant rise in seawater temperature during the Middle Oxfordian

Récifs, coraux et climats oxfordiens de la Téthys

Martin-Garin Bertrand, Lathuilière Bernard, Geister Jörn. Récifs, coraux et climats oxfordiens de la Téthys. In: Documents des Laboratoires de Géologie, Lyon, n°156, 2002. STRATI 2002. 3ème congrès français de stratigraphie. Lyon, 8-10 juillet 2002. pp. 154-155

New biological zonation of a late Jurassic coral reef complex (Lorraine, France)

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Correlation of reefal Oxfordian episodes and climatic implications in the eastern Paris Basin (France)

International audienceOxfordian reefal episodes of Lorraine and Burgundy have a long time been considered as contemporaneous. Biostratigraphic data and sequential evolutions peculiar to each region indicate their structural autonomy during Oxfordian times. A north-south-oriented well-logging transect shows that, during the Middle Oxfordian, a shallow reefal platform developed in Lorraine while thin deeper deposits occurred in Burgundy. In spite of their different ages, reefal episodes of Middle Oxfordian in Lorraine and Upper Oxfordian in Burgundy exhibit a broadly similar vertical evolution of coral communities. During the Late Oxfordian, the contemporaneous occurrence of a diversified assemblage in the Burgundy region, a colder coral assemblage characterized by eurytopic genera and the decrease in seawater isotopic temperatures in Lorraine can be explained by a shift in trophic conditions, a climatic change related to structural rearrangements in this strategic place and a modification of oceanic circulations between the arctic and the Tethyan regions

Geology facies model and coral associations of the Late Jurassic reef complex at Cap Ghir (Atlantic High Atlas Morocco)

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Succession des écosystèmes récifaux dans la carrière de Pagny-sur-Meuse (Lorraine) : premières considérations sur l’évolution des environnements de dépôt au passage Oxfordien moyen - Oxfordien supérieur

Carpentier Cédric, Martin-Garin Bertrand, Olivier Nicolas, Lathuilière Bernard, Gaillard Christian, Ferry Serge, Hantzpergue Pierre, Geister Jörn. Succession des écosystèmes récifaux dans la carrière de Pagny-sur-Meuse (Lorraine) : premières considérations sur l’évolution des environnements de dépôt au passage Oxfordien moyen - Oxfordien supérieur. In: Documents des Laboratoires de Géologie, Lyon, n°156, 2002. STRATI 2002. 3ème congrès français de stratigraphie. Lyon, 8-10 juillet 2002. p. 65