Mississippian (Lower Carboniferous) microfossils from the Chios Melange (Chios Island, Greece)

The Chios Melange is a thick Paleozoic wildflysch sequence that crops out on the Greek island Chios. It is composed of chert, limestone and volcanic blocks floating in a siliciclastic turbiditic matrix. New data suggest that the youngest blocks within the Chios Melange are clasts of 9 a breccia from the Kouramia-Nenitouria area that contain conodonts of late Visean or early Serpukovian age. The conodont fauna from the breccias is characterized by the genera Gnathodus and Lochriew, which favored deeper-water, open-marine facies. Elsewhere on the island, in the Papalia-Nagos area, calcareous microfossils of middle to late Visean age have been recovered from lime grainstone beds within the Chios Melange. Allochems making up the grainstones are interpreted to have been transported into deeper-water turbiditic facies, but there is no evidence of stratigraphic reworking. Age-diagnostic calcareous microfossils include the alga Koninckopora inflata and foraminifers in the genus Paraarchaediscus. In situ Mississippian microfossils indicate that the Chios Melange is older than Pennsylvanian (Upper Carboniferous) - Permian, as previously thought. The revised age suggests that the origin of the Chios Melange may be related to the development of an accretionary prism during the Hercynian Orogeny. (C) 2003 Editions scientifiques et medicales Elsevier SAS. All rights reserved.