TY - JOUR T1 - Late Pleistocene-Holocene evolution of the northern shelf of the Sea of Marmara JF - Marine Geology Y1 - 2009 A1 - Cagatay, M. N. A1 - Eris, K. A1 - Ryan, W. B. F. A1 - Sancar, U. A1 - Polonia, A. A1 - Akcer, S. A1 - Biltekin, D. A1 - Gasperini, L. A1 - Gorur, N. A1 - Lericolais, G. A1 - Bard, E. AB - Chirp sub-bottom profiling, multibeam bathymetric mapping and a combination of faunal and isotopic analysis of molluscs and foraminifera in sediment cores on the northern shelf of the Sea of Marmara (SoM) provide evidence of sea-level excursions, water exchanges between the adjacent Mediterranean and Black Seas, and oscillating salinity over the last 160 ka bp. During the marine isotope stages MIS-2, MIS-3, MIS-4 and MIS-6 the SoM disconnected from the Mediterranean Sea and evolved into a lake. During MIS-1, MIS-5 and MIS-7, the SoM reconnected and became salty once again. Sapropels formed shortly after each invasion of Mediterranean saltwater observed in our cores. Concurrent suboxic-dysoxic conditions prevailed over quite shallow substrates on the shelf. Ancient shorelines are pervasive at -85 m on the northern shelf and in the region of Prince Islands coincident with the elevation of the modern bedrock sill in the Canakkale (Dardanelles) Strait. At times when global (eustatic) sea level dropped below this sill, the surface of the SoM stabilized at its outlet and freshened. Thus this particular shoreline is interpreted as the edge of the most recent SoM lake that existed from about 75 ka bp to 12 ka bp. The freshening is observed in very light (-6 parts per thousand) values of delta O-18 measured on freshwater molluscs and the complete absence of foraminifera. Two brief lacustrine episodes during MIS-5 suggest that the level of the Canakkale outlet might have been as shallow as -50 m in the past, a likelihood supported by submerged terraces along its margins bounding the modern central channel and the presence of an euryhaline biofacies in Unit L4.1 corresponding to MIS-5b. delta O-18 profiles and carbon-14 dating show that salinification of the SoM and the blossoming of bioherms evolved rapidly after the latest connection with the Mediterranean at 12 ka bp. However, freshening proceeded more slowly once the connection was severed. (C) 2009 Elsevier B.V. All rights reserved. VL - 265 IS - 3-4 N1 - id: 1843; 500UN Times Cited:1 Cited References Count:80Y JO - Late Pleistocene-Holocene evolution of the northern shelf of the Sea of Marmara ER - TY - JOUR T1 - Reply to Comment on "The timing and evolution of the post-glacial transgression across the Sea of Marmara shelf south of Istanbul" by Hiscott et al., Marine Geology 248, 228-236 JF - Marine Geology Y1 - 2008 A1 - Eris, K. K. A1 - Ryan, W. B. F. A1 - Cagatay, M. N. A1 - Lericolais, G. A1 - Sancar, U. A1 - Menot, G. A1 - Bard, E. AB - In their comment Hiscott and co-authors adhere rigidly to ages and sources for sedimentary units in the subsurface of the Marmara shelf that they have previously reported in their publications from 2002 through 2007. This adherence is in spite of a superior age-depth model from our 13 m-long sediment core that penetrated deeply into the deposits under consideration and in disregard to the results of subsequent more-detailed and full-coverage mapping of the region under scrutiny. The age revisions are dismissed by the authors of the comment as representing sediments severely disturbed during coring. We rebut this criticism. The Bosporus source attributed by them to the sedimentary units sampled and dated by us appears to be driven by their conception that the Black Sea had a persistent outflow prior to its two-way connection with Marmara. Irrespective of whether the outflow was persistent, our reply shows that the drawing of the isopachs of the sedimentary units by Hiscott and coauthors was accomplished in a fashion to promote the Bosporus source hypothesis regardless of the geographic limits of their survey. The ages assigned to the units are equally indeterminate because the cores used by them have missing core tops of unknown lengths that are not discussed in their publications. Furthermore, the sub-bottom reflectors at the sites where the reflectors were calibrated to their only core without a missing top are actually hidden by the finite width of the bottom reflecting wavelet. (C) 2008 Elsevier B.V. All rights reserved. VL - 254 IS - 3-4 N1 - id: 784; 377ZE Times Cited:0 Cited References Count:33Y JO - Reply to Comment on "The timing and evolution of the post-glacial transgression across the Sea of Marmara shelf south of Istanbul" by Hiscott et al., Marine Geology 248, 228-236 ER - TY - JOUR T1 - The timing and evolution of the post-glacial transgression across the Sea of Marmara shelf south of Istanbul JF - Marine Geology Y1 - 2007 A1 - Eris, K. K. A1 - Ryan, W. B. F. A1 - Cagatay, M. N. A1 - Sancar, U. A1 - Lericolais, G. A1 - Menot, G. A1 - Bard, E. AB - High-resolution seismic reflection profiles and analyses of the sedimentary substrate at the Sea of Marmara (SoM) entrance to the Strait of Istanbul (Sol, Bosphorus) provide a detailed record of the transgression that took place after the SoM reconnected with the Mediterranean. The sediments progressively fill a paleo shelf valley that incised the margin from the Sol to the shelf break at the time of the pre-Holocene lowstand. We map seven seismic reflection units that can be confidently correlated to sediment cores by lithology and physical properties. Sediments in the cores are dated by radiocarbon methods. Early channel and levee deposits within the paleo valley belong to the Younger Dryas cold stage and record outflow from the Black Sea via the Sol. Small clinoform packages on the valley margin formed in proximity to climbing paleo shorelines. The elevations of these deposits conform to the sealevel history recorded in Barbados corals. The younger part of the succession includes a subaqueous prodelta sourced from the Kurbagalidere River. Its relatively young age when the Holocene sea had almost reached its modem level suggests that the thick progradational and aggradational clinoform development was primarily a response to sediment supply rather than the filling of expanding accommodation space. Our findings refute the hypothesis of Aksu et al. (Aksu, A.E., Hiscott, R.N., Mudie., P.J., Rochon, A., Kaminski, M.A., Abrojano, T., Yasar, D., 2002a. Persistent Holocene outflow fromn the Black Sea to the Eastern Mediterranean contradicts Noah's Flood hypothesis, GSA Today 10,(6), 3-7., Aksu, A.E., Hiscott, R.N., Kaminski, M.A., Mudie, P.J., Gillespie, H., Abrojano, T., Yasar, D., 2002b. Last glacial-Holocene paleoceanography of the Black Sea and Marmara Sea: stable isotopic, foraminiferal and coccolith evidence. Mar. Geol., 190, 119-149.) and Hiscott et al. (Hiscott, R.N., Aksu, A.E., Yasar, D., Kaminski, M.A., Mudie, P.J., Kostylev, V.E., MacDonald, J.C. Isler, F.I., Lord, A.R., 2002. Deltas south of the Bosphorus Strait record persistent Black Sea outflow to the Marmara Sea since similar to 10 ka, Mar. Geol., 190,95-118., Hiscott, R.N., Aksu, A.E., Mudie., P.J., Kaminski, M.A., Abrajano, T, Yasar, D., Rochon, A., 2007. The Marmara Sea gateway since similar to 16 ky BP: non-catastrophic causes of paleoceanographic events in the Black Sea at 8.4 and 7.15 ky BR In Yanko-Hombach,V, Gilbert, A.S., Dolukhanov, P.M. (Eds.), The Black Sea Flood Question, Springer, The Netherlands, 89-117.) that this deposit was supplied from the Sol and that its presence requires a persistent Black Sea outflow since 10 C-14 ka bp (not corrected from the reservoir age or calibrated). (c) 2007 Elsevier B.V All rights reserved. VL - 243 IS - 1-4 N1 - 210tuTimes Cited:36Cited References Count:52 JO - The timing and evolution of the post-glacial transgression across the Sea of Marmara shelf south of Istanbul ER -