Fig. 6
From: Highly fractionated chromium isotopes in Mesoproterozoic-aged shales and atmospheric oxygen
The isotopic composition of chromium (δ53Cr) compared to chromium enrichment. a Enrichment relative to Ti (Cr/Ti). Samples from the Shennongjia Group are given in orange circles, while modern sediments deposited in anoxic settings are given in black circles and modern oxic settings are given in green circles. Mesoproterozoic-aged shales from ref.30 are given in gray circles. b Enrichment relative to Al (Cr/Al) for samples of the Shennongjia Group. Cr/Al data are not available for other modern and ancient sediments. The shaded horizontal bar represents the δ53Cr range for crustal values39. All data and references are summarized in Supplementary Table 3
