2026-05-07T22:21:11Zhttps://riubu.ubu.es/oai/request

oai:riubu.ubu.es:10259/61092022-12-19T09:49:15Zcom_10259.4_2560com_10259_5086com_10259_2604col_10259.4_2561

Analysing non-coaxial folding effects in the Small Circle Intersection method Calvín Ballester, Pablo Pueyo Morer, Emilio L. Ramón Ortiga, Mª José Casas Sainz, Antonio M. Villalaín Santamaria, Juan José Palaeomagnetism Remagnetization Magnetismo Geología Magnetism Geology The Small Circle (SC) tools analyse the stereographic tracks (small circles) followed by the palaeomagnetic vectors during folding processes. Working with interfolding and synfolding remagnetizations, the Small Circle Intersection (SCI) method allows finding the best solution of grouping that should correspond with the remagnetization direction. Once this is known, it is possible to determine the magnetization age as well as the degree of bed tilting at this moment. The SC tools are based on some assumptions, among which the coaxiality between the different deformation events is the one addressed in this work (i.e. absence of vertical axis rotations, VARs, or differential horizontal axis rotations, dHARs). This assumption is based on the necessity of knowing the rotation axis for folding after the acquisition of the remagnetization, and SC tools consider the bedding strike as this axis, something that is only accomplished under coaxial folding. In order to explore how non-coaxiality affects the solutions derived from the SC methods, we first (i) identify the variables that control these errors through simple models that only consider two theoretical palaeomagnetic sites, after that it is possible (ii) to derive the mathematical relationships between them. Finally, we (iii) simulate errors derived from the use of SC tools using a population of 30 palaeomagnetic sites recreating different possible scenarios with VARs and dHARs in nature. Research financed by the projects DR3AM- CGL2014-55118 and CGL2016-77560-C2 from the Spanish Ministry of Science (MINECO) and by the Applied Geology (GeoAP-E0117R) and Geotransfer groups of the Government of Aragon, as well as by the project BU235P18 (Junta de Castilla y Leon, Spain) and the European Regional Development Fund (ERD). It has also benefited from the MAGIBER-II network (CGL2017-90632-REDT) funded by the Ministry of Science, Innovation and Universities. 2021-11-05T09:14:38Z 2021-11-05T09:14:38Z 2020-08 info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion 0956-540X http://hdl.handle.net/10259/6109 10.1093/gji/ggaa217 eng Geophysical Journal International. 2020, V. 222, n. 2, p. 940–955 https://doi.org/10.1093/gji/ggaa217 info:eu-repo/grantAgreement/MINECO//CGL2014-55118 info:eu-repo/grantAgreement/AEI/Plan Estatal de Investigación Científica y Técnica y de Innovación 2013-2016/CGL2016-77560-C2-1-P/ES/La remagnetización cretacica del alto Atlas Central como herramienta de reconstrucción geométrica de la estructura Pre-cenozoica info:eu-repo/grantAgreement/Junta de Castilla y León//BU235P18//Análisis arqueomagnéticos en materiales arqueológicos quemados de edad holocena y pleistocena info:eu-repo/grantAgreement/AEI/Plan Estatal de Investigación Científica y Técnica y de Innovación 2013-2016/CGL2017-90632-REDT info:eu-repo/semantics/openAccess application/pdf Oxford University Press