Fig. 1: SEM images of the BRC organic films.
From: Inherited geochemical diversity of 3.4 Ga organic films from the Buck Reef Chert, South Africa
a SEM [BSE] photomicrograph of a surface of freshly fractured chert, and corresponding EDX maps showing the distribution of carbonaceous films (dark; map ‘C’) in the chert matrix composed of microquartz (light; map ‘Si’); (b–f) SEM [SE] photomicrographs of individual films from which FIB foils have been extracted (red segments).
