Possible waterways between the Marmara Sea and the Black Sea in the late Quaternary: evidence from ostracod and foraminifer assemblages in lakes İznik and Sapanca, Turkey

Discussion: a critique of Possible waterways between the Marmara Sea and the Black Sea in the late Quaternary: evidence from ostracod and foraminifer assemblages in lakes İznik and Sapanca, Turkey, Geo-Marine Letters, 2011

“…… the latest flooding event must have occurred in the Holocene, given that marine microfossils were found in the youngest surface sediments of both lakes" (p. 85). Nazik et al (2011) acknowledge that 14 C dating of carbonate microfossils would be required for a more precise aging of the waterway connections. In their study, 47 surficial samples (uppermost 10 to 20 cm of the lake deposits) were recovered from the two lakes on irregular grids at various water depths using a grab sampler.…”

“…Nazik et al (2011) consider both this alternative connection and an additional possible waterway, starting from Gemlik Bay, crossing Lake İznik, and finally reaching the Black Sea through the Sakarya Valley. They suggest that both of these routes may have been active in the late Quaternary.…”

“…They suggest that both of these routes may have been active in the late Quaternary. Nazik et al (2011) base their hypothesis on the following considerations (we quote):…”

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

“…Unlike many studies which pointed to increased water levels during the Pleistocene era (Ardel 1953;Tanoglu and Erinc, 1956) or sea-water connections (Islamoglu, 2009;Nazik et al, 2010), there are very limited field data that suggest Holocene water-level variations in Iznik Lake.…”

“…Based on the fact that this fossil shell is typical of salt marine-waters, the finding confirms a suggestion that the lake was connected with the sea at 39790±360 BP based on AMS radiocarbon age (Beta, USA) from fossil shell of C. glaucum. However, Nazik et al, 2010 suggested a Holocene connection based on the presence of ostracode Limnocythere inopinata sevanensis Bubikyan, which is typical of brackish Black Sea waters (Nazik et al, 2010). These new findings have the potential to explain the initial precipitation of marine-like cements in present-day Iznik Lake.…”