The effects of anisotropic and non-linear thermoremanent magnetizations on Thellier-type paleointensity data
作者单位：Paleomagnetism and Geochronology LaboratoryKey Laboratory of Earth’s Deep InteriorInstitute of Geology and GeophysicsChinese Academy of Sciences
会议名称：《中国科学院地质与地球物理研究所2013年度（第13届）学术年会》
会议日期：2014年
学科分类：070801[理学-固体地球物理学] 07[理学] 0708[理学-地球物理学]
基 金：funding from a Young International Scientist Fellowship from the Chinese Academy of Sciences(grant number 2009Y2BZ5) NSFC Grant 41050110132
关 键 词：Archaeomagnetism Palaeointensity
摘 要：Numerous non-ideal factors can influence paleointensity data,but the detection of these factors remains problematic and new approaches to understanding how paleointensity data behave are *** this study,a recently developed stochastic model of single domain(SD) paleointensity behaviour is expanded to investigate the effects that anisotropic and non-linear thermoremanent magnetizations(TRMs) have on the paleointensity results and the parameters used to select *** model results indicate that before applying any form of correction these non-ideal factors can produce results that are self-consistent,but highly *** methods that are currently used to correct for anisotropic and non-linear TRMs are effective and greatly increase the likelihood of obtaining accurate *** corrections,however,do not restore the results to those of ideal SD samples measured with the same laboratory-to-ancient field ratio,but the data are restored to those of ideal SD samples with the equivalent laboratory-to -ancient magnetization ratios(M/M).The simulations indicate that non-linear and anisotropic TRM have no or only a weak influence on the parameters commonly used to select paleointensity data,which means that these non-ideal factors are effectively undetectable. These new models suggest that the paleointensity behaviour of thermally/chemically stable SD samples,whether they are ideally behaved,anisotropy or non-linear TRM corrected,is near universal and depends only on(M/M) and the choice of paleointensity protocol (***-type versus Thellier).Given the high self-consistency and highly inaccurate results that anisotropic and non-linear TRM can yield,it is essential to test for such effects and all Thellier-type paleointensity studies must include tests for anisotropic and non-linear TRM to assert the reliability of the data obtained.