Abstract

This study analyses variations in the size of black woody phytoclast and palynofacies types of shallow subtidal environments evolving to deeper subtidal environments, of latest Illyrdian-latest Fassanian age (Upper Muschelkalk). Some of the results display some discrepancies between elevated particle sizes that were supposedly deposited in a relative proximal source and the rich veryhachid palynofacies that are thought to represent distal marine environments. A case study of the succession in the Héming quarry, located in the Alsace-Lorraine trough (southwestern part of the intracratonic Germanic basin) reveals that : (1) the palynological assemblages are dominated by acritarchs belonging to micrhystridids, disaccate pollen and woody phytoclasts; (2) the abundance of phytoclasts, sporomorphs and marine groups is not correlated with lithologies; (3) the length of the processes of micrhystridids is not a useful parameter in defining palynofacies types. In carbonate ramp environments, many factors could have confused the palynological signals such as high-energy events and the water level on which the nutrient supply depended pro parte. All these factors seem to have been governed by climatic or tectono-eustatic events.

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