The Embu Complex of the Ribeira Belt, southeast Brazil, provides records of orogenic processes within the time period between Rodinia break-up and West Gondwana assembly. Recent studies have questioned the accretionary setting for the belt, suggesting an intracontinental setting. In this paper, we present new petrological, U–Pb and Rb–Sr data from metasedimentary rocks of the Embu Complex, discussing the implications for the tectonic evolution from Rodinia to West Gondwana in the Ribeira Belt. Sillimanite, sillimanite–K-feldspar and cordierite zones represent the high-grade metamorphic zones for the metamorphic event identified in the southern portion of the Embu Complex. Petrological and thermodynamic modelling data indicate that the high-grade metamorphic rocks of the complex attained conditions between 750–805 °C and 3.6–9.2 kbar. Monazite and zircon U–Pb data indicate that the high-grade metamorphic event occurred between 810–760 Ma, concomitant with igneous activity recorded during this period. In addition, zircon and apatite U–Pb ages, as well as, biotite and muscovite Rb–Sr ages, between 675–550 Ma record a slow cooling rate of 4.4 °C/Ma for the period between 675–640 Ma, and a late stage of shear zones development. These results reinforce the accretion of distinct units within the Ribeira Belt during the Neoproterozoic Era.

巴西东南部里贝拉带的恩布复合体提供了罗迪尼亚分裂和西冈瓦纳大陆组装之间时期内造山过程的记录。最近的研究质疑了该带的增生环境，表明是大陆内环境。在本文中，我们展示了来自 Embu 杂岩体变质沉积岩的新岩石学、U-Pb 和 Rb-Sr 数据，讨论了对 Ribeira 带中从 Rodinia 到 West Gondwana 的构造演化的影响。硅线石、硅线石-钾长石和堇青石带代表了 Embu 杂岩南部确定的变质事件的高品位变质带。岩石学和热力学模拟数据表明，复杂的高品位变质岩达到了 750-805 °C 和 3.6-9.2 kbar 之间的条件。独居石和锆石 U-Pb 数据表明，高品位变质事件发生在 810-760 Ma 之间，伴随着这一时期记录的火成岩活动。此外，锆石和磷灰石 U-Pb 年龄，以及 675-550 Ma 之间的黑云母和白云母 Rb-Sr 年龄记录了 675-640 Ma 期间 4.4 °C/Ma 的缓慢冷却速率，并且剪切带发育后期。这些结果加强了新元古代时期里贝拉带内不同单元的增生。和剪切带发展的后期阶段。这些结果加强了新元古代时期里贝拉带内不同单元的增生。和剪切带发展的后期阶段。这些结果加强了新元古代时期里贝拉带内不同单元的增生。