Figure 2

Lithological section of the interval studied here from the Sítio Sobradinho outcrop showing the positions of the stratigraphic samples (4BAr01A–4BAr01M) in the outcrop photographs and the facies photomicrographs to the right. The top of section (0 m) corresponds to the elevation datum 695 m. (a–d) Calcareous quartz arenite with glauconite grains (indicated by arrows): peloid type under PPL—parallel polarized light (a) and XPL—crossed polarized light (b) and foliated grains under PPL (c) and XPL (d). (e–g) Massive fossiliferous wackestone: foraminifera casts in SEM images (e, h), foraminifera, ostracode valves and peloids in a sparry calcite cement under XPL (f), non-oriented ostracode valves and peloids in a micritic matrix and several metallic grains (black euhedral and framboid) under PPL (g). (i–l) Laminated ostracode wackestone: oriented ostracode valves and carapaces in a micritic matrix under PPL (i) and XPL (j) and a silica grain disturbing the orientation of ostracodes under PPL (k) and XPL (l). (m–p) Carbonaceous and fossiliferous shale: an ostracode carapace disturbing the lamination under PPL (m) and XPL (n) and wavy carbonaceous and clay laminae with intercalated ostracode valves and few silty grains under PPL (o) and XPL (p). (q–t) Calcisphere mudstone: calcispheres indicated by arrows under PPL (q, r) and calcispheres in SEM images (s, t). Figure created by Juliana Guzmán on CorelDRAW version 22.0 (https://www.coreldraw.com).