The inner Apennines (Italy) are characterized by scattered outcrops of continent‐derived orogenic metamorphic units exposed along the Tyrrhenian coast from northern to southern Apennines. At least since the 1970s, some peculiar rocks exposed on Zannone Island (central Italy) have been described as the only Paleozoic‐Triassic metamorphic complex linking those exposed in the northern—with those in the southern Apennines. Assessing the protolith nature, thermobaric conditions, and structural features of what is accepted to be the metamorphic unit of Zannone is, therefore, crucial to elucidate the early paleotectonic evolution of the Apennines‐Tyrrhenian orogenic system. To that end, we interpreted seismic reflection profiles offshore Zannone, we carried out mesoscale and microscale structural investigations of representative outcrops on the island, performed X‐ray diffraction analysis, and K‐Ar and U‐Pb geochronology of representative clay gouge and syntectonic carbonate veins. Results show that the metamorphic rocks of Zannone can actually be reinterpreted as belonging to nonmetamorphic siliciclastic turbidites, likely deposited in foredeep settings, and coeval to the Oligocene‐Miocene Macigno Fm. of the northern Apennines. The turbiditic sequence was overthrust by Triassic dolostone in the early Miocene (~22 Ma), weakly deformed at <200°C, and downfaulted by postorogenic extensional faults starting ~7 Ma ago. Hence, Zannone represents a unique geological location in central Italy where to study the innermost (i.e. oldest) thrust sheet of the central‐northern Apennines, thereby shedding new light onto the early tectonics of the Apennines. Based on this evidence, a new evolutionary scheme for the early stage of the Apennines tectonic evolution is proposed.

中文翻译：

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证明赞诺内岛（意大利中部）上的古生代-三叠纪变质岩的存在：对第勒尼安-亚平宁山脉构造演化的早期意义

内亚平宁山脉（意大利）的特征是，从亚平宁山脉的北部到南部沿第勒尼安海岸暴露的大陆性造山变质单元的零散露头。至少从70年代开始，一些在赞诺尼岛（意大利中部）裸露的岩石被描述为唯一的古生代-三叠纪变质复合体，将北部和南部的亚平宁山脉的那些联系起来。因此，评估被认为是Zannone变质单元的原生岩的性质，高温高压条件和结构特征，对于阐明亚平宁-第勒尼期造山系统的早期古构造演化至关重要。为此，我们解释了赞纳诺（Zannone）海上的地震反射剖面，并对岛上有代表性的露头进行了中微尺度的结构研究，进行了X射线衍射分析，以及代表性的粘土凿和共构造碳酸盐岩脉的K-Ar和U-Pb年代学。结果表明，Zannone的变质岩实际上可以重新解释为属于非变质硅质碎屑浊积岩，可能沉积在前深层环境中，并与渐新世-中新世Macigno Fm相同。亚平宁山脉北部。在中新世早期（〜22 Ma），三叠系白云岩推覆了湍流序列，在<200°C时微弱变形，并在〜7 Ma以前由造山后伸展断层破坏。因此，Zannone代表了意大利中部一个独特的地质位置，在那里研究中北部亚平宁山脉的最里面（即最古老的）逆冲片，从而为亚平宁山脉的早期构造提供了新的亮光。根据这些证据，