Fauna and flora in submarine early-Holocene lake-marl deposits from the southwestern Baltic Sea

Studies of plant and animal macrofossils have been carried out on early-Holocene lake marIs from the southwestern Baltic. The records have been dated to the interval from c. 8500 to 7800 C-14 years BP by correlating pollen assemblages to an onshore radiocarbon dated pollen diagram. The sediments contain from 5 to 81% carbonate, and only few macroscopic remains of wetland and terrestrial taxa. The plant and animal (mainly mollusc) macrofossils reflect deposition at the outer edge of the belt with submerged macro-limnophytes, in the lower littoral, perhaps at water depths at 4-7 m. The ratio between the shells and opercula of the snail Bithynia tentaculata points to some post-mortem disturbance, but it can be concluded that the water was highly alkaline and mesotrophic.