Mustafa Bozcu

Physico-Chemical Characteristics of Coastal Dunes on the Saros Gulf, Turkey

Abstract In the present paper, several physico-chemical characteristics of dune sands in a rapidly prograding delta environment on the east coast of the Saros Gulf, northwest Turkey, are presented. For accurate characterization and classification of coastal dunes 4 km long and maximum 500 m wide, the pH, CaCO3 content, electrical conductivity, organic matter content, and x-ray fluorescence spectroscopy data were assessed. In terms of dune classification, our results showed the presence of three distinctive coastal dune types: (1) foredune, (2) semistable gray dune, and (3) stationary dark dune. Field observations combining with aerial photo and satellite image interpretations for the period between 1962 and 2007 also revealed dune loss and migration in the dunefield as a consequence of bidirectional effects of south-westerly and northwesterly winds and wind-force rise of lagoon waters.

First note on marine-like cementation of Late Holocene beachrock, Iznik Lake (Turkey)

Micro-fabric characteristics and optically stimulated luminescence (OSL) dating results are presented to discuss the controlling agents and timing of beachrock cementation on the fresh-water Iznik Lake shoreline. The beachrocks are made up of grain-supported polygenic conglomerate containing 20.42% carbonate with encrusted grains, basically as micrite coatings, isopachous aragonite rims, cryptocrystalline void fills and meniscus bridges. The optical ages of twelve samples yielded ages that range from 4.226±0.569 ka on the lowermost beds to 0.706±0.081 on the uppermost. This is the first report of precipitation of marine-like cements in Iznik Lake. The abundant aragonite-dominated cement is likely indicative of precipitation-prone dry evaporative conditions from the climatic optimum to the last millennia.