A local clay‐varve chronology and proglacial sedimentary environment in glacial Lake Peipsi, eastern Estonia

Abstract

A local clay-varve chronology and proglacial sedimentary environment in glacial Lake Peipsi, eastern Estonia TIIT HANG Hang, T. 2003 (June): A local clay-varve chronology and proglacial sedimentary environment in glacial Lake Peipsi, eastern Estonia. Boreas, Vol. 32, pp. 416-426. Oslo. ISSN 0300-9483.Ten cores consisting of varved clay from the northern part of Lake Peipsi in eastern Estonia have been correlated using varve thickness variations and specific marker varves into a 375-year floating varve chronology. Continuous sedimentation during gradual ice recession is concluded from a clear transition from proximal to distal varves. Cyclic variations in varve thickness are caused mainly by thickness changes of clayey winter layers. This is interpreted to indicate increased influx of finer material due to faster melting of the glacier. The cyclic pattern of thickness change is explained by alternating periods of increased and decreased melting of the ice. Simultaneous accumulation of varved clay in glacial Lake Peipsi and in the Luga and Neva basins of Russia is concluded from the good visual correlation between the mean varve thickness diagrams for the three chronologies. Because the varve chronologies from northwestern Russia have been tentatively correlated to the Swedish varve chronology, the timing of the clay accumulation in glacial Lake Peipsi is placed between c. 13 500 and 13 100 varve years BP.

Timing of the deglaciation and the late-glacial vegetation development on the Pandivere Upland, North Estonia

“…This estimation is older than recently suggested (Kalm, 2012;Saarse et al, 2012;Lasberg & Kalm, 2013;Vassiljev & Saarse, 2013) and does not fit with 10 Be-based dates, which indicate that the Pandivere belt formed 13 100±1100 10 Be years BP (Rinterknecht et al, 2006). The varved clay results and their correlation with the Neva ice marginal belt (Saarnisto & Saarinen, 2001) provide grounds for estimating the age of the Pandivere stadial at 12 700 varve years (Hang, 1997), redefined to 13 300 varve years by Hang (2003) and later to more than 13 300 cal. yr BP (Hang & Kohv, 2013).…”

Late-glacial to Holocene aeolian deposition in northeastern Europe – The timing of sedimentation at the Iisaku site (NE Estonia)

“…13.9 to 13.7 ka in western Estonia (Hang et al, 2011), and ca. 13.5 to 13.1 ka in northeastern Estonia and in the vicinity of Lake Ladoga (Saarnisto and Saarinen, 2001;Hang, 2003). The most recent study (Vassiljev and Saarse, 2013) points to development of the A 1 phase of the BIL in front of the Pandivere ice-marginal during 13.8e14.0ka.…”

“…All deposits investigated here directly overlie the glaciolacustrine sediments of the glacial Lake Peipsi, which correlates with the Pandivere ice marginal zone of the Late Weichselian glaciation (Hang, 2003;Kalm et al, 2011). The minimum age of the Pandivere belt is indirectly supported by AMS radiocarbon ( 14 C) dates of 14,450 ± 240 cal.…”

“…However, due to the unique geological Late-glacial development in Estonia considerable effort has been put into setting up general chronological frameworks (Kalm, 2006), e.g. varve chronologies (Hang, 2003;Talviste et al, 2012;Hang and Kohv, 2013), beryllium dating (Rinterknecht et al, 2006), and relative dating using the palaeobotanical record (Kihno et al, 2011;Amon et al, 2012;Veski et al, 2012;Laumets et al, 2014). There are studies compiling ages for this area (Kalm et al, 2011;Lasberg and Kalm, 2013); these include ages from one very early luminescence study (Raukas and Hüüt, 1988).…”

Late Weichselian varve archives re-explored to assess proglacial sedimentary chronologies using the principles of tree-ring analysis

“…Both of these factors tend to widen the accommodation space and, consequently lead to thinner varves. Therefore the existence of the trend in the diagrams is due to factors inherent to progressing deglaciation, which would be supported by the general similarity between the trends in different diagrams from different regions (Hang, 1997(Hang, , 2003Sauramo, 1918Sauramo, , 1923Strömberg, 1990;Wohlfarth et al, 1998). Accordingly, the formula (equation 1) would in large part separate these influences from those external to ice recession and base level rise; likewise, the mathematical elimination of the trend (i.e.…”