Paleointensity Results From Pliocene Lavas of the Lesser Caucasus Obtained Using the Multispecimen Parallel Differential pTRM Method: A Comparison With Thellier‐Thellier and IZZI Data

• Published in: Journal of geophysical research. Solid earth 2021-04, Vol.126 (4), p.n/a
• Main Authors: Sánchez‐Moreno, Elisa M., Calvo‐Rathert, Manuel, Goguitchaichvili, Avto, Vashakidze, George T., Camps, Pierre, Morales‐Contreras, Juan, Vegas‐Tubía, Néstor, Lebedev, Vladimir A.
• Format: Article
• Language: English
• Subjects: Criteria; Data; Earth Sciences; Geophysics; High reliable paleointensities; IZZI protocol; Lesser Caucasus; Methods; multispecimen protocols; Pliocene; Polarity; Sciences of the Universe; Thellier‐Thellier protocol; Volcanology
• ISSN: 2169-9313; 2169-9356
• DOI: 10.1029/2020JB019682

We report paleointensity results obtained with the multispecimen method (MSP) over the Pliocene sequence of Apnia (Georgia) which records a polarity reversal. Paleointensity determinations with the multispecimen technique were performed on 12 flows with the original (MSP‐DB) and the domain‐state corrected (MSP‐DSC) protocol. Eight MSP‐DSC determinations passed the proposed quality criteria. To obtain highly reliable data through the agreement between intensity values from different methods, MSP results were combined with paleointensities from a previous study with Thellier‐type methods and especially strict selection criteria (RCRIT) on same flows (Sánchez‐Moreno et al., 2020). Application of this multimethod procedure resulted in three new paleointensities including both MSP and Thellier‐type results and an additional one obtained with two different Thellier‐type methods, yielding one paleointensity of 36.9 µT in the normal‐polarity, and three paleointensities between 19.2 and 24.1 µT in the reverse‐polarity section. Additionally, Thellier‐type data have been reinterpreted in this study with more flexible criteria (TTP) and the results combined with the MSP data. As a result, four flows yield paleointensities including MSP and Thellier‐type determinations and seven include paleointensities obtained with two different Thellier‐type methods. Results range from 37.2 and 44.3 μT in the normal‐polarity and from 12.5 to 24.6 μT in the reverse‐polarity section. Comparison of results from the four flows yielding multimethod determinations applying RCRIT criteria with those from the same flows under TTP criteria yields no significant difference in paleointensity values and their experimental uncertainty. Thus, application of a multimethod approach supports the possibility of using TTP criteria. Key Points New paleointensity results using the multispecimen parallel differential partial thermoremanent magnetization (pTRM) method with domain‐state corrections Comparison and combination of multispecimen and Thellier‐type paleointensity methods applying and analyzing different selection criteria High‐quality low Pliocene paleointensities obtained with a multimethod approach