Climatic Signature and Radiocarbon Chronology of Middle and Late Pleniglacial Loess from Eurasia: Comparison with the Marine and Greenland Records

Recent investigations devoted to the Eurasian loess formations have provided an integrated high-resolution climatic sequence well radiocarbon dated between 13.4 and 42.5 kyr BP on charcoal and wood remains. Here, we show that the reproducible climatic signature of this loess sequence can be compared by proxy-correlation with the Greenland ice climatic signals, taking into account the distribution of the aeolian components in both records. This correlation allows situating with precision the series of 14C dates obtained from loess with regard to the Greenland climatic sequence. In this way, comparing the atmospheric loess-derived 14C chronology with the chronologies of the marine sequences becomes possible.

Charcoal and wood remains for radiocarbon dating Upper Pleistocene loess sequences in Eastern Europe and Central Siberia

The present paper concerns long Upper Pleistocene loess sequences from Eastern Europe with multiple Upper Palaeolithic occupations, rich in charcoal, as well as loess sequences from Central Siberia with abundant wood remains. These complementary records have allowed establishing a high-resolution climatic sequence integrating 24 interstadial episodes between ca 42.5 and 10 kyr BP. Here, we discuss the methodology of dating used to fix the chronological framework of this climatic sequence, based on a set of 240 available radiocarbon dates, mainly produced on charcoal and wood remains. Special attention is paid to the strategy of sampling charcoal and wood material in strict accordance with stratigraphy, as well as to the preparation process in the laboratory for extraction, cleaning, identification and selection of the best fragments to date. Careful stratigraphic drawing and detailed positioning of the samples for each geological layer are also considered in order to clarify the relationship of the obtained dates with respect to any sedimentary, pedological or archaeological event to be dated. The reliability and accuracy of the dates obtained from loess sequences are further controlled by the internal consistency with regard to stratigraphy. Palaeoenvironmental implications are also discussed.