Geological setting and sedimentology of the studied Sturtian IFs. (A) Geological maps of the study areas of the Chuos Formation, Kunene, Namibia (1, Okavare; 2, Landeck; 3, Lowenfontein; 4, Orusewa); the Yudnamutana Subgroup, Adelaide Fold Belt, South Australia (5, Oraparinna; 6, Willippa; 7, Holowilena South); and the Kingston Peak Formation, southern Death Valley, California (8, Sperry Wash; 9; Kingston Range). (B) Representative stratigraphic columns of the IF-bearing Sturtian glacial intervals of the Chuos Formation, Yudnamutana Subgroup, and Kingston Peak Formation (see SI Appendix, Figs. S1–S8 for stratigraphic columns from all study areas). (C) Interbedded diamictite and IF of the Chuos Formation, interpreted as evidence of IF deposition in an ice-contact glaciomarine environment. (D) Laminated IF clast within ferruginous diamictite, Yudnamutana Subgroup. (E) Laminated IF interbedded with siltstone and sandstone turbidites, interpreted to represent an ice-distal glaciomarine environment, Kingston Peak Formation. (F) Simplified global continental reconstruction at ca. 680 Ma highlighting the paleogeographic distribution of Sturtian IFs (red squares). The dark gray areas correspond to cratonic regions and the light gray areas represent the inferred distribution of the fragments of the supercontinent Rodinia; inferred plate boundaries and subduction zones are represented by black and red lines, respectively. Reprinted from ref. 67. Copyright (2017), with permission from Elsevier.