Geological study for a wetland restoration: the case of the drained Mouria Lake (W. Peloponnese).

Abstract

The Μouria Lake was drained for cultivation during late 1960’s. A 0.5-ha large pilot-scale wetland is now constructed in order to study the sedimentological lakerestoration aspects. The uppermost horizons (up to 3 m thick) consist of fine sediments (mud, silt, clay) of fluvial origin, deposited in a lacustrine environment and constituting the lagoonal bottom material, which extents all over the area ever covered by the original Mouria Lake. A sand layer (3 m beneath the current surface) constitutes the substrate of the lagoonal bottom revealing a higher energy deposition environment in comparison to the overlying fine sediments. High pH and electric conductivity values reveal strong alkaline environment and high content of dissolved solids, respectively. The sediments reveal high CEC, as a result of high clay minerals content. Other main mineral phases that occur include quartz, feldspars and calcite. The weathering of marginal rocks is the major factor controlling the mineralogical-geochemical composition of the sediments. The strong alkaline features of the sediments inhibit trace element mobilization. Continuous monitoring of the chemical composition is necessary in order to predict and prevent a possible mobilization of hazardous trace elements and the subsequent release to the environment.

Lake-Level Changes and Their Paleo-Climatic Implications at the MIS12 Lower Paleolithic (Middle Pleistocene) Site Marathousa 1, Greece

“…The anticorrelation of the Na/Ti, Mg/Ti, and Si/Ti ratio with PC2 supports our interpretation. Alkaline waters with pH>9 are known from today's dry and carbonate-rich environment of the Peloponnese (Chatziapostolou et al, 2013;Katrantsiotis et al, 2016;Weiberg et al, 2016). Highly alkaline waters are here related to the weathering of the surrounding rocks, consisting of Na-rich albite and Mg-rich dolomite, among others (Tsiftsis, 1987).…”

“…It has been pointed out that diatom records from the Peloponnese are rare, due to a dry and carbonate-rich environment favoring generally alkaline conditions (Weiberg et al, 2016). Studies, conducted on the Agios Floros fen to the south and on Lake Mouria to the North-West of the Alfeios River delta, reported highly alkaline waters (pH>9) resulting from the weathering of the surrounding rocks, which most likely contributed to the dissolution of the diatoms (Chatziapostolou et al, 2013;Katrantsiotis et al, 2016). Apart from the occasional diatom presence, sponge spicules are abundant throughout the investigated sequences.…”