Time-scale and astronomical forcing of Serbian loess-paleosol sequences

Abstract

The loess in Vojvodina region in Northern Serbia is regarded as one of the thickest and most complete paleoclimate archives in Europe. Recent studies showed that loess in Vojvodina spans the last million years. Based on the interprofile correlation between two most important loess-paleosol sequences Stari Slankamen and Titel Loess Plateau a synthetic profile was formed regarded as Stratotype Record of Serbian loess (SRSL). The synthetic profile has a total thickness of 62. m and is comprised of 10 loess layers intercalated with nine pedocomplexes. A new astronomically tuned age model is proposed based on correlating peak magnetic susceptibility (χ) responses with the timing of June perihelia. This target curve is derived from analysis of regional climate proxy responses during the last interglacial and independently dated last glacial-interglacial cycle of Serbian loess-paleosol sequence. The use of a precession index target as the only tuning target presents the requirement of minimal tuning approach, which means that only the precession frequencies of the record will be manipulated.Spectral and wavelet analyses of tuned magnetic susceptibility record reveal the presence of frequencies corresponding to 139kyr, 94kyr, 65kyr and small amplitude cycles of 43 and 23kyr in χ record. Spectral analysis of frequency dependent magnetic susceptibility (χfd) has spectral content concentrated around 100kyr and 77kyr, while higher frequency cycles are below significance level. There is a strong 245kyr peak in spectral results of both χ and χfd records that needs additional attention.Around 800kyr in SRSLχ time scale and between 900kyr and 600kyr in SRSLχfd series the 100kyr cycles become dominant, which could be identified as the period of Mid-Pleistocene Transition. This is the first record of this paleoclimate transition in the Pannonian basin. The results presented in this study highlight the potential of Serbian loess-paleosol sequences for investigation of detailed and long-term climate reconstruction over continental Eurasian extent. © 2014 Elsevier B.V.