MOESM1 of Generation of billow-like wavy folds by fluidization at high temperature in Nojima fault gouge: microscopic and rock magnetic perspectives

Additional file 1: Fig. S1. Transmitted light microscope images of thin-section samples with billow-like wavy folds in their laminated microtextures. Dashed red lines outline the billow-like wavy folds, and dashed black dot lines indicate width (l) and the wavelength (λ). Fig. S2. Optical images (left) and surface magnetic field distributions observed by MI magnetic microscope (right) of thin-section samples shown in the relative intensity map. Dotted black lines indicate the billow-like wavy folds. White regions correspond to near-average magnetic field, and red (blue) regions correspond to upward (downward) oriented fields. The black arrow indicates a direction of fault movement estimated from the billow-like wavy folds. (a), (b), and (c) correspond to blocks 1, 2, and 4 in Fig. 1d, respectively. Fig. S3. Thermomagnetic curves of incohesive grayish fault gouge samples (a) and a subsequent heating curve (b). The curve (a) was characterized by hump above 370 °C. The induced magnetization on a heating step increases at about 370 °C, reached a maximum at 500 °C, and decreases from 500 °C to 570 °C. This hump suggests the presence of thermally unstable iron-bearing minerals that can be transformed to magnetite at temperature above 370 °C. The subsequent heating curve (b) showed that the induced magnetization decreases to the Curie temperature of around 550 °C and increases reversibly back to the same level of original magnetization. This indicates the existence of magnetite without thermal oxidations to hematite even after heating up to 650 °C. Table S1. Relationship between pixel counting and volume fraction of fault grains. Table S2. Raw data of remanent magnetization of the five fragment gouge samples after stepwise heating experiment at 100 μT. Table S3. Raw data of remanence magnetization of two fragment gouge samples under natural remanent magnetization (NRM), alternating field demagnetization (AFD) at 100 mT, isothermal remanent magnetization (IRM) at 1 T and IRM at 1 T after heating at 600 °C