Fig. 4
From: Highly fractionated chromium isotopes in Mesoproterozoic-aged shales and atmospheric oxygen
The isotopic composition of chromium (δ53Cr) compared with organic carbon (TOC) concentration, Fe concentration, Re/Al, and Cr/Al. As in Fig. 3, samples are plotted sequentially and relative to stratigraphic position (from top to bottom), but not as function of exact stratigraphic position. The gray vertical bar in the δ53Cr plot represents the crustal average value39
