Exploring Smoothing and Interpolation in Thellier-Type Paleointensity Determinations

Smoothing and interpolation of zero-field (Z) and infield (I) heating steps in Thellier-type paleointensity determinations have been tested. Paleomagnetic samples of different materials were artificially magnetized with an applied field of 50 µT. Six samples were measured following the standard doub...

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Detalles Bibliográficos
Autores: Casas, Lluís|||0000-0003-0948-8658, Ortiz, Marc, Di Febo, Roberta|||0000-0002-1102-8231
Tipo de recurso: artículo
Fecha de publicación:2025
País:España
Institución:Universitat Autònoma de Barcelona
Repositorio:Dipòsit Digital de Documents de la UAB
Idioma:inglés
OAI Identifier:oai:ddd.uab.cat:319136
Acceso en línea:https://ddd.uab.cat/record/319136
https://dx.doi.org/urn:doi:10.3390/min15080873
Access Level:acceso abierto
Palabra clave:Paleomagnetic intensity
Thellier
Smoothing
Interpolation
Single-step
Descripción
Sumario:Smoothing and interpolation of zero-field (Z) and infield (I) heating steps in Thellier-type paleointensity determinations have been tested. Paleomagnetic samples of different materials were artificially magnetized with an applied field of 50 µT. Six samples were measured following the standard double-heating Coe-variation experimental protocol, and the obtained results were used to test several mathematical functions to smooth the experimental data. The best smoothed results were obtained using a Five Parameters Logistic (5PL) function that resulted in field estimates of good quality, although not better than those obtained experimentally. Therefore, the smoothing of de- and remagnetization data appears unnecessary. In addition to smoothing, the tested functions can be used to interpolate additional Z and, indirectly, also I steps. Interpolation using cubic Hermite splines (without any smoothing) displays a better performance than interpolation (and smoothing) using the 5PL function. A new single-step heating method is presented, combining experimental and interpolated de- and remagnetization steps. The new method would not be applicable for retrieving reliable ancient field intensities on its own, but it could save measuring time under some circumstances.