GEOMAGNETIC EXCURSION RECORD PRESERVED IN THE SPELEOTHEM FROM WESTERN CAUCASUS: FIRST DATA

Abstract

The study of the geomagnetic field evolution on minor timescales, in particular of such significant events as geomagnetic reversals and excursions, has acquired particular relevance nowadays due to the increased attention of mankind to the environment. The question of how exactly abrupt changes in the characteristics of the geomagnetic field affect the climate and biosphere remains largely debatable; the idea of the speed and dynamics of these changes is also very vague. "Classical" geological objects and existing methods provide limited opportunities for highly detailed reconstructions of geomagnetic field variations; therefore, paleomagnetologists are looking for new objects and approaches to solve this problem. The research that we have begun involves the use – for the first time in Russia – of speleothems to study secular variations of the geomagnetic field.This brief communication presents paleomagnetic records of two drill-cores from the flowstone from Vorontsovskaya cave, located on the western flank of the Caucasus Mountains in the valley of the river Kudepsta. Preliminary results indicate the presence of a geomagnetic excursion record in both drill-cores. Further study of the samples from Vorontsovskaya cave will make it possible to compare the discovered event with known excursions, as well as to clarify its age, duration, and dynamics.

Keywords

• geomagnetic excursion
• secular variations
• speleothems
• quaternary
• environmental magnetism
• paleomagnetism
• geomagnetic field evolution