Fig. 1: BGS, detrital zircons and Fe-bearing inclusions.
From: Hadaean to Palaeoarchaean stagnant-lid tectonics revealed by zircon magnetism
a, Field photo of BGS. Scale bar, 5 cm. b, Example section of BGS approximately 300 μm thick. Scale bar, 1 mm. c, Example of detrital zircon (arrow) in BGS matrix. Scale bar, 1 mm. d,e, Reflected-light images (100×) of zircon BGS2-z51, with the boxes highlighting Fe-oxide inclusion (magnetite) at 0° (d) and 90° (e) polarization. Scale bars, 50 μm. f, SEM EDS spectra of Fe inclusion highlighted in d and e (see Extended Data Fig. 2 for further SEM images and EDS analyses). g, SEM BSD image of silicate inclusion in zircon BGS5-z30 with EDS analysis location identified by the circle (see Extended Data Fig. 1 for further SEM images and EDS spectra). Scale bar, 1 μm. h, EDS spectra of g with Fe signal highlighted. i, SEM BSD image of Fe-oxide inclusion (magnetite) in zircon BGS2-z50 with EDS spectra analysis location highlighted by the circle. Scale bar, 200 nm. j,k, EDS analyses of i. An Fe signal was not observed using a 20-keV beam (j) but was detected using a 28-keV beam (k), emphasizing that the inclusion is at depth (>4 μm). (Methods. Corresponding reflected-light images showing inclusion extinction are in Extended Data Fig. 2.) l, SEM BSD image of Fe-oxide particles in zircon BGS5-z36 with EDS location highlighted by the circle (further reflected-light and SEM images are shown in Extended Data Fig. 2). Scale bar, 200 nm. m, EDS spectra of l.
