Figure 2: Model of open ocean seawater δ98/95Mo (δ98/95MoOSW) in response to different proportions of Mo sinks.
From: Rise to modern levels of ocean oxygenation coincided with the Cambrian radiation of animals
(a) Contours of δ98/95MoOSW as a function of the relative sizes of the euxinic (FEux), weakly oxic (FwOx) and strongly oxic (FsOx) sinks, assuming that the Mo cycle is in steady state. The black dot represents the modern budget. The upper shaded area would represent coupled expansion of euxinia and the strongly oxic condition relative to the weakly oxic condition, which is unrealistic28. The blue arrow denotes a possible oxygenation trend of the ocean, dictated by the Mo data and the model, from the Neoproterozoic to the early Cambrian. (b) A 3D contour surface of δ98/95MoOSW=+2.34‰ as a function of areal (A) fractions of the above redox settings, assuming that the Mo cycle is in steady state. The black dot represents modern redox area distributions; red and yellow dots represent maximum euxinic (1%) and weakly oxic (2%) areas, respectively.
