“Geo-archives of a Coastal Lacustrine Eco-system”: Lake Bafa (Mediterranean Sea)

Abstract

A hypothetical novel, which aims to summarize the whole geological history of the coastal area surrounding the Mediterranean Sea, probably contains a sum of intensive and impressive topics, such as tsunamis, storms, earthquakes, volcanic activities, human-nature interactions, and their products. These abrupt geo-event changes (e.g., water chemistry fluctuations) remark a dynamic nature of this unique coastal area. Paleolimnological studies of a coastal lacustrine archive (i.e., Lake Bafa, Turkey), associated with syngenetic deposits accumulated in neighboring geological settings (i.e., swamp, deltaic, lagoon, marine), has allowed us to reconstruct the local geological history. Following this hypothesis, we aimed at investigating the paleoenvironmental establishment of the Lake Bafa and surrounding coastal area. Lithologic and geochemical investigations of the lacustrine ("BAF37:4.2 m) core and surrounding swamp ("BS":12 m) sediments supplied us an excellent geo-archive, continuously accumulated during the last 4.5 ky. Following conclusions are provided concerning the main depositional stages: Recent swamp-lacustrine separated stage (S-I: last 0.8 ky), lagoon stage (S-II.: 0.8-1.75 ky BP), marine-river interaction stage (S-III: 1.75-2.7 ky BP), and marine-dominated stage (S-IV: 2.7-4.5 ky BP). Our observations indicate that ecosystem characteristics of the basin have been mainly controlled by the hydroclimate and geotectonic processes.

Sediment geochemistry of the section Tagay-1 at Olkhon Island (Lake Baikal, Eastern Siberia): a contribution to palaeoenvironmental interpretations

“…We have further used a binary elemental ratio-ratio proxy model (K 2 O/Al 2 O 3 vs. Ga/Rb) (cf., Roy and Roser 2013) to reconstruct the palaeoclimatic history of the sediments. Ratios of the redox-sensitive elements V/(V+Ni), Ni/Co, V/Cr; Fe/Mn and binary diagram of V/Cr-Ni/Co were applied for detailed investigations of the past lake water column properties (Maslov 2005;Bulkan et al 2019).…”

“…In addition to investigations of the element concentrations, distribution of V/Cr, U/Th, Ni/Co, V/(V+Ni), Mn/Fe (smoothed with moving average), and cross-correlation of V/Cr-Ni/Co were applied for the assessment of the past lake water column redox properties (Bulkan et al 2019) (Figs. 9, and 10).…”