FIRST RESULTS OF COMPLEX DATING AND GROWTH RATE ESTIMATION OF SPELEOTHEM FROM VORONTSOVSKAYA CAVE (KRASNODAR REGION, RUSSIA)

Abstract

Speleothems are unique archives of information about climate, geomagnetism, and ecological conditions of past epochs of the Earth, and over the past two decades have been successfully used for paleoclimatic and paleomagnetic studies. The uniqueness of these geological objects lies in the peculiarities of their formation and preservation in them of a wide range of geochemical, geological and geophysical proxies, and, most importantly, in the ability to obtain time series of these proxies in an unprecedentedly accurate resolution using 230Th/U, 14C and some other geochronological methods, as well as incremental chronology. This paper presents the first results of dating the Vor speleothem from the Vorontsovskaya Cave (Krasnodar region), which preserved a record of the geomagnetic excursion, obtained by 230Th/U α-spectrometry, 14C dating, and incremental chronology. Such studies have been carried out in Russia for the first time. Despite the limitations of using the methods of isotope geochronology, it was possible to obtain a limit on the age of the excursion, which probably occurred no earlier than 5500–6000 years ago. At the same time, the incremental chronology made it possible to determine with great accuracy the duration of the main phase of the excursion, which equals 871 ± 16 years, during which the virtual geomagnetic pole was in the southern hemisphere, and also to obtain the upper limit on the age of the excursion, which probably occurred no later than 5.5–6 thousand years ago.