The protocratonic core of the São Francisco craton assembled during the 2.1–2.0 Ga Transamazonian orogeny. Orosirian Fe‐rich sequences that extend from the northwestern border of the São Francisco protocraton (Colomi Group) to the southeast under the Espinhaço Belt (the < 1.99 Ga Serra da Serpentina Group) record the opening of an intracratonic basin with the episodically developed ferruginous waters prior to the initiation of the Espinhaço rift at 1.8 Ga. Ferruginous conditions developed again during deposition of the Canjica Iron Formation of the < 1.7 Ga Serra de São José Group in the Espinhaço rift (contemporaneously with felsic magmatism; Conceição do Mato Dentro Rhyolite and Borrachudos Granitic Suite) and extensive sandstones of the < (1666 ±32) Ma Itapanhoacanga and < (1683 ±11) Ma São João da Chapada Formations. In the upper São João da Chapada Formation, banded hematitic phyllite also records input of Fe‐rich fluids. The young age of these iron formations with respect to the conventionally accepted 1.88 Ga age for the youngest shallow‐marine Paleoproterozoic iron formations, the apparent absence of granular facies (granular iron formations), and yet shallow‐water (above fair‐weather base) depositional environment indicate that an unusual setting developed in a large basin after the Great Oxidation Event, in the aftermath of the Transamazonian orogeny. We propose that mantle plumes led to the opening of a previously unrecognized rift system, that could have caused the magmatism, supplied hydrothermal Fe and led to the opening of the Espinhaço, Pirapora, and Paramirim rifts, later obliterated by the Araçuaí orogenic belt during the Neoproterozoic to Early Paleozoic Brasiliano orogeny. The rift system did not develop into an open continental margin but probably evolved into a broad sag basin, stretching across the São Francisco and Congo cratons.

中文翻译：

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大氧化后事件圣弗朗西斯科克拉通上的Orosirian–Statherian铁地层：大地构造意义

圣弗朗西斯科克拉通的原生克拉通核心在2.1–2.0 Ga泛亚马逊造山运动期间聚集。从圣弗朗西斯科原生动物（科洛米群）的西北边界一直延伸到埃斯皮尼亚科带（<1.99 Ga Serra da Serpentina群）东南的东南的富铁质富铁岩层记录了克拉通盆地的开裂，并逐渐形成了含铁质的水在1.8 Ga的Espinhaço裂谷开始之前。在Espinhaço裂谷中<1.7 Ga Serra deSãoJosé组的Canjica铁组沉积期间，铁质条件又发生了发展（同时具有长岩浆作用；Conceiçãodo Mato Dentro流纹岩和Borrachudos （1666±32）Ma Itapanhoacanga和<（1683±11）MaSãoJoãoda Chapada地层的花岗岩组和广泛的砂岩。在SãoJoãoda Chapada上部地层，带状偏斜晶石也记录了富铁流体的输入。相对于传统上公认的最年轻的浅海古元古生铁构造，这些铁构造的年龄相对于传统公认的1.88 Ga年龄，明显缺乏颗粒相（粒状铁构造），但是却没有浅水（高于公平天气基础）沉积环境表明，在大氧化事件之后，横穿亚马逊造山运动的结果，一个大盆地发育出异常的环境。我们认为，地幔羽导致了以前无法识别的裂谷系统的开放，这可能引起岩浆作用，供应了热液铁，并导致了埃斯皮尼亚科，皮拉波拉和帕拉米里姆裂谷的开启，后来在新元古代至早古生代巴西利亚造山运动中被阿拉索阿造山带消灭。裂谷系统并没有发展成一个开放的大陆边缘，而是可能演变成一个宽阔的流陷盆地，横跨圣弗朗西斯科和刚果克拉通。