Preliminary magnetostratigraphic study of the Late Cretaceous dinosaur site from Villeveyrac-Meze Basin, southern France
Résumé
A magnetostrati graphic study was performed on continental Upper Cretaceous beds in the L'Olivet quarry, Villeveyrac-Meze Basin (Herault, France). Nearly all specimens subjected to progressive thermal demagnetization procedures exhibit opposite polarities for the low- and high-temperature magnetization components. The high-temperature component shows reverse polarity, characteristic of the Late Cretaceous magnetization, which is well isolated between 200 degrees and 450 degrees C. The overall mean paleomagnetic direction (incl. = -39.1 degrees, decl. = 160.7 degrees, k = 15, a(95) = 10) suggests a counterclockwise vertical axis rotation of about 15.1 degrees +/- 8.3 with respect to the expected Late Cretaceous direction calculated from the Eurasian polar wander curve (incl. = -49.0 degrees, decl. = 174 degrees). Combined with local biostratigraphic data, the L'Olivet sequence can be correlated with polarity chron C33.lr, corresponding to the Early Campanian with an age of 83.5 to 79.5 Ma.