Geochemistry of surface sediments of a coastal Lake Sarbsko (northern Poland)

The main goal of the pre sented re search was to in ves ti gate spa tial dis tri bu tion of sur face sed i ments and to rec og nize re la tion ships be tween chem i cal com po si tion of wa ter and sed i ments in a coastal Lake Sarbsko (north ern Po land). The Lake Sarbsko is a fresh wa ter ba sin. The wa ter col umn is well ox y gen ated and wa ters ex hibit only mi nor spa tial vari - abil ity of chem i cal com po si tion in di cat ing rapid and good mix ing. Sur face sed i ments of Lake Sarbsko are strongly di - ver si fied with re spect to chem i cal com po si tion. The sed i ments of Lake Sarbsko are char ac ter ized by el e vated con tent of terrigenous sil ica in di cat ing en hanced in put of clastic ma te rial from the wa ter shed and/or in creased dy nam ics of the lake wa ters. More over, SiO2ter is strongly neg a - tively cor re lated with SiO2biog, or ganic mat ter and el e ment con tents, which ar gues for di lut ing ef fect of the for mer to - wards authigenic com po nents of sed i ments. Ba si cally, terrigenous sil ica (quartz) con tent is high est in the lake shores and de clines to wards the lake cen ter. Biogenic sil ica, or ganic mat ter and most of el e ments dis play re versed ten dency. CaCO3 was en coun tered in three iso lated ar eas, where it co-oc curs with FeS. It is an tic i pated that pre cip i ta tion of cal - cite in Lake Sarbsko re sulted from postdepositional pro cesses. Spa tial dis tri bu tion of Fe, Mn, Ca, Mg, Na and K in Lake Sarbsko is also gov erned by their geo chem i cal af fin i ties to or ganic mat ter (Fe), Fe/Mn ox ides (Fe, Mn), sulphides (Fe), clay min er als (Na, K, Mg, Mn) and car bon ates (Ca, Mn).