Quelques implications paléoclimatiques de l'observation de bois fossiles du Wealdien du bassin de Mons (Belgique) - Résultats préliminaires. Observations on Wealden fossilised wood from the Mons Basin (Belgium) and their palaeoclimatic implications – Preliminary results

Tree growth, including radial growth, is controlled by a complicated combination of climate-related factors. In seasonal climates many species of trees form clearly defined annual growth rings. Quantitative and qualitative analyses of growth rings are high resolution proxies of ancient environments, thus facilitating studies of past climates. We have applied this method to growth rings of early Cretaceous softwood branches from the Wealden facies of the Mons Basin, Belgium. Preliminary results confirm that during the early Cretaceous, the Mons Basin was located at 30-35°N, presumably in a tropical climate, with a succession of marked dry and wet seasons (KOEPPEN's climate type Aw). The Mean Sensitivity coefficient (the difference in a sequence of rings of the widths of consecutive ring pairs /average ring width) is high (above 0.4), and indicates unstable palaeoenvironmental conditions.