1 research outputs found
Magnetic dating of the Holocene monogenetic Tkarsheti volcano in the Kazbeki region (Great Caucasus)
The radiocarbon technique is widely used to date Late Pleistocene and Holocene lava flows. The significant difference
with palaeomagnetic methods is that the 14C dating is performed on the organic matter carbonized by the rock
formation or the paleosols found within or below the lava flow. On the contrary, the archaeomagnetic dating allows
to date the moment when the lava is cooling down below the Curie temperatures. In the present study, we use the
paleomagnetic dating to constrain the age of the Tkarsheti monogenetic volcano located within the Kazbeki Volcanic
Province (Great Caucasus). A series of rock-magnetic experiments including the measurement of hysteresis curves,
isothermal remanence, back-field and continuous thermomagnetic curves were applied. These experiments indicated
that Pseudo-Single-Domain Ti-poor titanomagnetite is responsible for remanence. A characteristic remanent magnetization
was obtained for all twenty analyzed samples yielding a stable single magnetization component observed
upon both thermal and alternating field treatments. Comparison of the mean directions obtained (Inc = 48.6º,
Dec = 6.4º, A95
= 4.0° and K = 67) with the SCHA.DIF.14k model yielded two main time intervals (4740–4650 or 4427–
4188 BC) as the best age estimate of the Lesser Tkarsheti lava flow. These results suggest an earlier age (between
approximately 200 and 700 years) for this monogenetic lava flow than expected from the estimated age provided by
a former 14C dating obtained in 1973 on woody remains. This first attempt to use the archaeomagnetic technique in
the Caucasus indicates that the SCHA.DIF.14k geomagnetic model may be successfully used for dating purposes in
the region.Projects BU0066U16 and BU235P18 (Junta de
Castilla y Leon, Spain) and the European Regional Development Fund (ERDF).
AG is grateful for financial support of CONACyT 252149 and UNAM-PAPIIT
project 101717. MC-R and AC acknowledge the financial support given by
the Junta de Castilla y León (project BU235P18) and the European Regional
Development Fund (ERD)