Abstract The opening of the South Atlantic in the Early Cretaceous was the final stage of the complex rifting history of SW Gondwana. In this contribution we reassess the chronology of Mesozoic basin formation in southern South America and Africa and integrate it in the long-term breakup history of SW Gondwana. Triassic rifting is characterized by intracontinental rifting in Africa (Karoo I phase), and retro-arc extension on the SW-margin of Gondwana. In the Early Jurassic, the impingement of the Karoo plume triggered rifting in Eastern Africa, producing the Karoo II basins (and the Colorado and Salado basins on the Argentinean shelf). East Africa rifting ultimately lead the breakup of Eastern from Western Gondwana in the Middle Jurassic. In Patagonia, the Austral, Malvinas and other related basins formed in association with the synextensional emplacement of the Chon Aike magmatic province in the Patagonian retro-arc. In the Late Jurassic the Rocas Verdes back-arc basin opened in southern Patagonia, while oblique rifting in the core of the Late Paleozoic Gondwanides orogen produced the Outeniqua and Rawson/Valdes basins. The South Atlantic Rift initiated in the Early Cretaceous associated with present-day E-W extension. Rifting occurred diachronically from south to north, initiating in the previously thinned Rawson/Valdes-Outeniqua segment. A precursor oblique rift system and a larger degree of extension in this segment could explain the lack of Seaward Dipping Reflectors (SDR) south of the Colorado-Cape fracture zones. Rifting and SDR emplacement occurred progressively to the north along different rift segments, producing strongly asymmetric conjugate margins.

中文翻译：

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冈瓦纳西南的中生代裂谷演化：一个多相的、与俯冲相关的、伸展历史，负责沿阿根廷大西洋边缘盆地的形成

摘要 早白垩世南大西洋的开放是冈瓦纳西南部复杂裂谷历史的最后阶段。在这篇文章中，我们重新评估了南美洲南部和非洲中生代盆地形成的年代，并将其整合到西南冈瓦纳的长期破裂历史中。三叠纪裂谷的特征是非洲大陆内裂谷（Karoo I 期）和冈瓦纳大陆西南缘的弧后延伸。在早侏罗世，卡鲁羽流的撞击引发了东非的裂谷，产生了卡鲁 II 盆地（以及阿根廷大陆架上的科罗拉多和萨拉多盆地）。东非裂谷最终导致了中侏罗世东部冈瓦纳大陆和西部冈瓦纳大陆的分裂。在巴塔哥尼亚，澳大利亚，马尔维纳斯和其他相关盆地的形成与巴塔哥尼亚后弧中 Chon Aike 岩浆区的同伸侵位有关。在晚侏罗世，Rocas Verdes 弧后盆地在巴塔哥尼亚南部开放，而晚古生代冈瓦尼德造山带核心的斜裂谷产生了 Outeniqua 和 Rawson/Valdes 盆地。南大西洋裂谷起始于与现今 EW 延伸相关的早白垩世。裂谷从南到北历时发生，起始于先前变薄的 Rawson/Valdes-Outeniqua 段。前体斜裂谷系统和该段更大程度的延伸可以解释科罗拉多-开普断裂带以南缺乏向海倾角反射体（SDR）的原因。