Supplementary data sets

Data Set S1. AMS data. AMS measurements were carried out using a 3D rotator AGICO MFK-1CS Kappabridge operating at 976 Hz with an applied field strength of 716 A/m. Specimens with group (Subunit A: G1=lapill + ash; G2 = bombs; G3= ash dominated. Subunit B; G4 = Lapilli dominated samples from site B2; G5 = matrix supported block collected from site B3; G6 = lapilli dominated, framework supported block collected from Site 3. Km = Bulk Susceptibility, K1 = Kmax Axis (most anisotropic), K2 = Kint axis (intermediate), K3 = Kmin axis (weakest axis of anisotropy). L = Lineation, F = Foliation, P = total anisotropy, T = shape. KnDec = Declination of axis Kn, KnInc = Kn axis inclination. F = test for anisotropy on Kmax, F12 test for anisotropy Kint, F23 test for anisotropy on Kmin. &lt;3.5 is a failed test of anisotropy; samples with two or more failed axes are excluded. E12, E23, E13 = error for Kmax, Kint and Kmin axes of declination/inclination, respectively. <br> Data Set S2. (see ds02.csv). Magnetic mineralogy of 19 subsamples was investigated using hysteresis and Isothermal Remanent Magnetization (IRM) on a Princeton Measurements Corporation Vibrating Sample Magnetometer (VSM, MicroMag 3900) using maximum applied fields of 500 mT, sufficient to saturate the samples. Saturation magnetization (Ms), remanence magnetization (Mr), coercivity (Bc) were determined from hysteresis data and saturation remanence (Mrs) and remanence coercivity (Bcr) were determined from IRM