Experimental and numerical simulation of the acquisition of chemical remanent magnetization and the Thellier procedure

On the Reliability of Absolute Palaeointensity Determinations on Basaltic Rocks Bearing a Thermochemical Remanence

“…As regards the crystallization CRM, the current blocking temperature T* must be replaced by the reaction temperature T CRM , so that the formula can be transformed into which predicts a possible significant excess of TRM over CRM since the factor ( v / v b ) 1/2 is by definition greater than unity. This prediction is in a good agreement with the results of isothermal experiments modeling the creation of CRM on titanomagnetite‐bearing basalts during up to 200 hr at annealing temperatures T CRM from 350 to 500 °C (Draeger et al, ; Gribov et al, , ; Shcherbakov et al, ). These annealing experiments indeed revealed a rather strong (1.5–4 times) difference in the intensities of the created TRMs and CRMs, suggesting that the CRMs created in these experiments are likely crystallization CRMs.…”

“…CRMs have been artificially created in laboratory experiments by isothermal annealing at T CRM = 350–500 °C of basaltic samples containing homogeneous TM grains (e.g., Draeger et al, ; Gribov et al, , ; Shcherbakov et al, ). In accordance with the predictions by Stacey and Banerjee (), these studies found that the CRM/TRM ratio was lower than one, leading to an underestimation of B anc by 20–80% in spite of unambiguous linear sections on the Arai‐Nagata diagrams.…”

Using Preisach Theory to Evaluate Chemical Remanent Magnetization and Its Behavior During Thellier‐Thellier‐Coe Paleointensity Experiments

“…The concave-up curvature in our gCRM Arai plots was also previously reported for models of gCRMs carried by non-and interacting systems (e.g., McClelland, 1996;Shcherbakov et al, 2017Shcherbakov et al, , 2021. The high-temperature linear segments of our gCRM and gCRM(T) Arai plots underestimating the paleointensity is consistent with results from Shcherbakov et al (2017); Shcherbakov and Sycheva (2019).…”

“…The lower thermal stability of gCRMs relative to TRMs is consistent with previous theoretical studies of non‐interacting and interacting assemblages (McClelland, 1996; Shcherbakov & Sycheva, 2019; Shcherbakov et al., 1996, 2017, 2021). In contrast to this study, Shcherbakov et al.…”

“…Shcherbakov et al. (2017) found the high temperature portions of Arai plots for high‐temperature gCRM( T ) grown at 400°C underestimated the applied field by ∼60%–70% for the gCRM( T ) case.…”