New detailed structural data from the Fuegian Andes including new ages and cross-cutting relationships with intrusive rocks, as well as an appraisal of published structural data, support that this orogen evolved as a basement-involved thrust-fold belt after initial formation in an arc-continent collision scenario. New structural data from a deformed 84 Ma intrusive indicate that structures from the collisional event in the Argentine Fuegian Andes are of Campanian age, comprising only the youngest and less intense deformation of the orogenic wedge. In the internal thrust-fold belt, these structures are cut by intrusives with new ages of 74 Ma (Ar/Ar on hornblende). The superposition of thrusts on these early structures indicates a subsequent event in which a thrust-fold belt formed since the Maastrichtian-Danian. Additional new data confirm brittle-ductile thrusting in the central belt, with thrusts joining a common upper detachment in the base of the Lower Cretaceous rocks. These thrusts formed a first-order duplex system that transferred the shortening accommodated in the foreland until the Miocene.

中文翻译：

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Fuegian 逆冲褶皱带：从弧形大陆碰撞到最南端安第斯山脉的逆冲变形

来自 Fuegian Andes 的新的详细结构数据，包括新时代和与侵入岩的横切关系，以及对已发表结构数据的评估，支持该造山带在弧形初始形成后演化为一个涉及基底的逆冲褶皱带-大陆碰撞场景。来自变形的 84 Ma 侵入岩的新结构数据表明，来自阿根廷安第斯火山碰撞事件的结构属于坎帕阶，仅包括造山楔最年轻且强度较小的变形。在内部逆冲褶皱带中，这些构造被新年龄为 74 Ma（角闪石上的 Ar/Ar）的侵入岩切割。这些早期构造上的逆冲叠加表明随后发生了自马斯特里赫特-大年以来形成逆冲褶皱带的事件。额外的新数据证实了中央带中的脆性-韧性逆冲推力，逆冲带加入了下白垩统岩石底部的一个共同的上拆离层。这些推力形成了一个一级双重系统，将容纳在前陆的起酥油转移到中新世。