Models and MT responses for 3-D lamindated structures
To check the accuracy of the effective bulk resistivity for 3-D laminated structure, we conducted numerical experiments for various models with lamellae structures. The 3-D MT responses (i.e. the actual model respnses) in 30 periods from 0.01 Hz to 10000 s are modelled for a regular observation array on the surface by using ModEM proposed by Egbert and Kelbert (2012). For comparison, we also calculated MT responses for the model in which the lamellae structure is replaced by a 3-D effective anisotropic block (i.e. the approximate model responses) using modular finite volume approach for 3-D MT anisotropic modelling proposed by Guo et al. (2020). And then the accuracy of the effective resistivity can be assessed through the average relative error between the two responses. Here we put the model files for each laminated model (Laminated_Model*.rho) and the corresponding effective anisotropic model (Equivalent_Model*.ani) and their responses (actual_model_responses.dat and approximate_model_responses.dat) into a single folder. For Model C and Model E, we also give the equivalent model derived from Merzer and Klemperer's formula (Equivalent_Model*_Merzer.ani) and the corresponding responses (approximate_model_responses_Merzer.dat). Model_E_irregular_lamellae_distribution represent the model with irregular lamellae distribution, i.e. the center of a lamella offsets from the center of four adjacent lamellae in the adjacent layer and we calculated its effective bulk resistivity using average overlap ratio which is the same as that of Model E. Model_E_rhom_5000 and Model_E_rhom_1000 represent that the matrix resistivity of Model E was changed from 10000 ohm.m to 5000 ohm.m and 1000 ohm.m, respectively.