Abstract The superposition of the Ribeira Orogen (590-560 Ma) on the southern segment of the Southern Brasilia Orogen (630-605 Ma) generated a region known as the tectono-metamorphic interference zone. This zone is characterized by the almost orthogonal superposition of structures and metamorphic isograds attributed to the Ribeira Orogen on older structures and metamorphism belonging to the Southern Brasilia Orogen. A flat-lying nappe stack characterizes the Southern Brasilia Orogen, and it presents top to the east tectonic transport with intense ductile deformation inside the nappes, visible by the development of a strong E-W stretching lineation and related sheath folds. In the Ribeira Orogen more open upright folds, with axial planes dipping steeply to SE predominate, often with a down dip stretching lineation. In the study area, located in this interference zone, descriptive criteria permit grouping of three sets of structures, attributed to three deformation phases, Dn, Dn+1 and Dn+2, here understood as either separated in time or parts of a progressive deformation. Dn produced the main schistosity, Sn, dipping steeply to the south/southeast; associated tight folds and a strong stretching lineation (Ln), plunging shallowly to E/NE, are also ascribed to this phase. Dn+1 generated open to tight regional folds with NE-SW axes and axial planes dipping moderate to steeply to SE. Gentle to open Dn+2 folds with subvertical ENE-WSW trending axial planes refolded older structures locally. Superposed structures between these phases, of type I (Dome and Basin), type II (Mushroom) and type III (Walking Stick) were recognized. The attitude of the structures of these three phases and the type of interference patterns allow to interpret Dn as related to the northeastward tectonic transport in the southern part of the Southern Brasilia Orogen and Dn+1 and Dn+2 as reflecting the NW-SE shortening typical for the Ribeira Orogen deformation. The folds and the interference pattern between Dn and Dn+1 are predominantly coaxial. Our understanding of this coaxiallity is that the strong NE-SW linear anisotropy related to thrusting to NE during the Southern Brasilia Orogen (Dn) was used as fold axes by the NW-SE shortening related to the Ribeira Orogen.

中文翻译：

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巴西利亚南部和巴西东南部里贝拉造山带之间构造干涉带叠置结构的案例研究

摘要 里贝拉造山带（590-560 Ma）在南巴西利亚造山带（630-605 Ma）南段的叠加产生了一个被称为构造变质干扰带的区域。该带的特点是里贝拉造山带的构造和变质等梯度几乎正交叠加在巴西利亚南部造山带的旧构造和变质作用上。一个平坦的推覆叠层是南巴西利亚造山带的特征，它呈现出从顶部到东部的构造运输，推覆内部具有强烈的延展性变形，通过强大的 EW 拉伸线理和相关的鞘褶皱的发展可见。在里贝拉造山带更开放的直立褶皱，轴向平面急剧倾斜到 SE 占主导地位，通常具有向下倾斜的拉伸线。在研究区，位于这个干涉区，描述性标准允许将三组结构分组，归因于三个变形阶段，Dn、Dn+1 和 Dn+2，这里理解为在时间上分开或渐进变形的部分。Dn 产生了主要的片理，Sn，向南/东南急剧倾斜；相关的紧密褶皱和强烈的拉伸线纹（Ln），浅向 E/NE，也归因于这个阶段。Dn+1 产生对紧密的区域褶皱开放，NE-SW 轴和轴向平面向 SE 中度至陡峭倾斜。温和地打开 Dn+2 折叠，具有近垂直 ENE-WSW 趋势的轴向平面在局部重新折叠旧结构。识别出这些相之间的叠加结构，即 I 型（圆顶和盆地）、II 型（蘑菇）和 III 型（手杖）。这三个阶段的结构姿态和干涉模式的类型允许将 Dn 解释为与巴西利亚造山带南部的东北向构造运输有关，而 Dn+1 和 Dn+2 则反映了 NW-SE 缩短典型的里贝拉造山带变形。Dn 和 Dn+1 之间的褶皱和干涉图案主要是同轴的。我们对这种同轴性的理解是，与南巴西利亚造山带 (Dn) 期间向 NE 逆冲相关的强 NE-SW 线性各向异性被与 Ribeira Orogen 相关的 NW-SE 缩短用作折叠轴。