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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.

John R. Commons and colleagues established the basic model for independent public utility regulation in the United States at the turn of the twentieth century, based on documented market and public interest failures. After limited success and repeated failures in the implementation of regulation, Harry M. Trebing and others at the Federal Communications Commission (FCC) in the late 1960s and 1970s revised and strengthened the model as well as the implementation capabilities of regulators, based on the regulatory weaknesses and unique opportunities for reform in the telecommunication industry. This model was then adapted to improve the regulation of other public utilities. Whereas the new model has also had limited success, the experience accumulated through it has prepared the ground for an inevitable third wave of regulatory reform.