Activities in 2005 – 2006  (Figs 11, 16).

Fig. 11. Investigated sites in Leningrad Oblast (1 – Nevsky Lesopark; 2 - Nevsky Pyatachok; 3 – Pasha River [Ust-Rybezhna]; 4 – Oyat River;; 5 – Staroja Ladoga; 8 – Besovsky peat-bog.

To clarify the post-glacial evolution of the Baltic and Ladoga basin with the special reference to the exact chronology of the ‘Ladoga transgression’ and the establishment of the Neva River the detailed geomorphologic and stratigraphic observations were performed at two key sites along the Neva: the ‘Nevsky Lesopark’ (The Neva Forest Reserve, Fig. 12) and ‘Nevsky Pyatachok’ (The Neva Bridgehead, Fig. 13). At two sites the high-frequency sampling for radiocarbon measurements, pollen and diatom analyses have been performed. The obtained data will enable one to find out the exact date of the establishment of the Neva River, as a consequence of the maximum rise of the level of the Ladoga Lake.

Fig. 12. Nevsky Lesopark: Deposits of the Ladoga Transgression, overlaying peat and gyttia.

Fig. 13. Nevsky Pyatachok: Gyttja and peat overlaying deposits of the Ladoga transgression.

Gepmorphological investigations were carried put at Ryurik’s Hill-Fort in Novgorod (Fig. 15), and at Mayata Hill-Fort (Fig. 16). To establish detailed chronology of hydrological changes in the basins Ladoga Lake, with special reference to the exact age of the ‘Ladoga transgression’ detailed geomorphologic and stratigraphic observations were performed in the river valleys of the Volkhov, Svir, Pasha and Oyat, south of the Ladoga Lake. Several test-pits have been made on the slopes of the lower terraces of the River Pasha (at Rybezhna village, Figs. 20, 21), and the River Oyat (Fig. 14). In the latter case, high-frequency sampling for radiocarbon measurements, pollen and diatom analyses were performed. The analyses are in progress. The obtained evidence will enable one to exactly date the maximum rise of the lake level in the course of the ‘Ladoga transgression.

Fig. 14. Ladoga transgression deposits on the Oyat River.

To clarify the changes in climate and vegetation, and the human impact on vegetation the coring has been carried out at Besovskoye and Radberik peat-bogs (Figs. 15, 19).

Fig. 15. Coring Besovskoye peat-bog.

Fig. 16. Investigated sites in Novgorod Oblast (7 – Mayata hill-fort; 8 -  Radberik peat-bog).

Fig. 17. Excavations at Rjurik’s Hill-Fort (Novgorod).

Fig. 18. Mayata Hill-Fort (Prof. Nosov at the right).

Fig. 19. Coring and sampling at Radberik peat-bog.

Fig. 20. Pasha River.

Fig. 21. Ust-Rybezhna site (in the foreground).

Detailed stratigraphic investigations and sampling were carried out at Staroja Ladoga settlement (Figs. 22, 23).

Fig. 20. Staroja Ladoga: archaeological deposits of the 9^th century AD, overlaying the sediments of the Ladoga transgression.

Fig. 21. INTAS expedition at Staroja Ladoga excavation site (Prof. Kirpichnikov in the middle).

Preliminary conclusions:

• During the Late Glacial period, the Ladoga Lake formed a deep north-eastern bay of the Baltic Ice Lake (BIL). Following the BIL collapse at ca. 10250calBC, the Ladoga Lake remained connected with the Baltic via a strait in the northern part of the Karelian Isthmus. Its detailed chronology has been established resulting from the recent studies at Veshchevo (Heinijoki).
• The site with the earliest evidence of human presence at Antrea-Korpilahti, radiocarbon-dated to c 9200-8250 cal BC (Matiskainen 1989, 71) lies in a bay of this strait.
• The sites with the early evidence of pottery-making (Sperrings, I:1 style) are synchronous with the maximum Pajanne Lake level, 5300-5000 BC (Siiriainen 1970).  An earlier age for the Sperrings assemblage has been obtained at Heppo-jarvi near St. Petersburg: 5560-5250 cal BC.
• New evidence suggests that the outflow from the Ladoga Lake into the Gulf of Finland ceased at 2300-1300 BC. The influx of fresh water and the tectonic uplift of Central Scandinavia caused a rise of the water level of the Ladoga Lake, lerading to a ‘Ladoga transgression’.
• Recently obtained series of radiocarbon dates indicates that the Ladoga transgression in the south was a short-lived episode between 1100-1000 calBC.
•  The lake level abruptly fell when a new outflow via the River Neva was formed an c.1000 BC.
• The fall of the lake level opened the way for agricultural colonisation of low-laying levels in the Volkhov-Ilmen hydrological system.
• This resulted in the emergence of a network of agricultural settlements, and, eventually, urban-type trade- and military centres along the waterway. 
• The lowermost strata of archaeological sequence of Staraja Ladoga settlement show the radiocarbon age of 1360±50 BP (or 641 - 761  AD cal), in agreement with the archaeological estimate.