Extended Data Fig. 2: Chemical analysis (STEM-EDX) of the intergranular amorphous phase in specimen NF1050-1.
From: Stress-induced amorphization triggers deformation in the lithospheric mantle
a, e, i, STEM bright-field images of the three areas investigated. b, f, j, Combined STEM and chemical Si maps, showing the presence of Si in the amorphous phase. c, g, k, Combined Si and Mg maps showing continuity of composition (Mg, Si) between the forsterite grains and the amorphous phase. Mg enrichment of the pyroxene grain is evident. d, h, i, Combined Si and Mg maps after quantification, performed using an existing method76 on the basis of the stoichiometric oxides, with standard specimens used to obtain the k factors77 of Mg and Si. In d, where the amorphous layer is larger, the thickness correction can be done accurately, showing that the amorphous phase has exactly the composition of forsterite. In h and i, the amorphous layers are smaller and thinner, with non-homogeneous thicknesses rendering quantification less reliable, so the local deviations observed in the thinnest regions should be taken with care.
