Several sag-type basins apparently developed from rift systems, but there is no consensus about how and if these grabens influenced the sedimentation of the post-rift thermal subsidence phase. The Ediacaran Jaibaras Rift Basin is one of the best-exposed sedimentary records among the NE Brazil late Precambrian – early Cambrian rift system, cropping out at the eastern margin of the intracratonic Parnaíba Basin and extending below it towards the west. Here we present detrital zircon U–Pb ages of rocks from the Jaibaras (Aprazível Formation) and Parnaíba (Ipu Formation) basins, in order to understand the provenance patterns, maximum depositional ages (MDA) and age relationship between these units. The MDA for the Aprazível Formation (c. 499 ± 5 Ma) indicates a Cambrian age for the upper part of the Jaibaras Basin. The bulk U–Pb data indicate that the Ipu Formation started to deposit during late Cambrian and/or Early Ordovician time, despite its MDA (c. 528 ± 11 Ma) being older than that of the Aprazível Formation. Detrital zircon provenance suggests that the primary source areas for the early deposits of the Parnaíba Basin were mountains related to the Brasiliano Orogeny to the south and SE (e.g. Rio Preto and Riacho do Pontal metamorphic belts). Finally, our data emphasize the key change in source areas from the rift to the initial deposition of the intracratonic phase, indicating major depositional style changes between both basins after the Gondwana assembly.

几个凹陷型盆地显然是从裂谷系统发育而来的，但对于这些地堑如何以及是否影响裂谷后热沉降阶段的沉积尚无共识。Ediacaran Jaibaras 裂谷盆地是巴西东北部晚前寒武世-早寒武世裂谷系中出露最好的沉积记录之一，出露于克拉通内帕纳伊巴盆地的东缘，并在其下方向西延伸。在这里，我们介绍了 Jaibaras（Aprazível 组）和 Parnaíba（Ipu 组）盆地岩石的碎屑锆石 U-Pb 年龄，以了解这些单元的物源模式、最大沉积年龄（MDA）和年龄关系。Arazível 组的 MDA（c. 499 ± 5 Ma) 表明 Jaibaras 盆地上部的寒武纪年龄。大量 U-Pb 数据表明 Ipu 组在晚寒武世和/或早奥陶世期间开始沉积，尽管其 MDA（c.  528 ± 11 Ma）比 Arazível 组早。碎屑锆石来源表明，Parnaíba 盆地早期矿床的主要源区是南部和东南部与巴西利亚诺造山运动相关的山脉（例如 Rio Preto 和 Riacho do Pontal 变质带）。最后，我们的数据强调了从裂谷到克拉通内阶段初始沉积的源区的关键变化，表明冈瓦纳组装后两个盆地之间的主要沉积样式变化。