Archaeological Sites of A. A. Inostrantsev and Holocene Tectonics of South Ladoga Region: Geological Context

Abstract

The archaeological sites of A. A. Inostrantsev (Late Mesolithic–early iron age) were found in 1878 during the construction of canals on the southern coast of Lake Ladoga. Their cultural layer is now below the current water level and buried under the multimeter strata of sediments of the Late Holocene Ladoga transgression. The palaeogeographic conditions of existence and the modern geological context of these sites are the classical, oldest and still unsolved problem of Quaternary geology in northwestern Russia. On the basis of detailed geological, geomorphological, litho-, palino- and chronostratigraphic investigation of late- and post-glacial deposits, it is established that the geological structure of the Quaternary strata in the area of the sites has a number of fundamental features. Among them it should be noted: (1) the basin and subaeral Medium-Late Holocene deposits of the same age are located at the same height; (2) time stretching of the final (regressive) phase of the Ladoga transgression in the lower reaches of the Volkhov River; (3) archaeological sites of reticular (textile) ceramics in the lower reaches of the rivers Volkhov and Syas’ are located below synchronous water level; (4) the asymmetry of the structure of the left and right banks of the Volkhov — including a reduction in the thickness of the Early Holocene member until its complete erosion in the territory east of the Volkhov, the young age and anomalous thickness of the sands with discoveries of A. Inostrantsev on the track channels, as well as the emergence of accommodation space in the Late Holocene and the formation of a lagoon, where a thick stratum of Ladoga transgression sediments accumulated. These features control the spread of A. A. Inostrantsev’s discoveries and are apparently associated with the differentiated sin- and postsedimentation submergence of the Volkhov–Syas’ interfluve in the Late Holocene (its amplitude increases to the north).