Silurian-Devonian Boundary In Se Anatolia (1): Organic Matter Variation As A Function Of The Depositional System At The Hazro Area

At present, Silurian-Devonian boundary sequences are primarily distinguished by faunal changes which affected several groups of organisms, e.g., graptolites, conodonts, chitinozoans, (Paris et al., 1981; Walliser, 1996). Chlupac and Kukal (1986) described this marine faunal change in comparison with other Silurian bioevents as a minor, relatively gradual but globally traceable event. Nevertheless, the driving forces for this event as well as the parallel occurrence of first land plants, which started to conquer the continents since the Middle Silurian, are still under discussion.