The Proterozoic evolution of northern Siberian Craton margin: a comparison of U–Pb–Hf signatures from sedimentary units of the Taimyr orogenic belt and the Siberian platform

Identifying the cratonic affinity of Neoproterozoic crust that surrounds the northern margin of the Siberian Craton (SC) is critical for determining its tectonic evolution and placing the Craton in Neoproterozoic supercontinental reconstructions. Integration of new U–Pb–Hf detrital zircon data with regional geological constraints indicates that distinct Neoproterozoic arc-related magmatic belts can be identified within the Taimyr orogen. Sedimentary rocks derived from 970 to 800 Ma arc-related suites reveal abundant Archean and Paleoproterozoic detritus, characteristic of the SC. The 720–600 Ma arc-related zircon population from the younger Cambrian sedimentary rocks is also complemented by an exotic juvenile Mesoproterozoic zircon population and erosional products of older arc-related suites. Nonetheless, numerous evidences imply that both arcs broadly reworked Siberian basement components. We suggest that the early Neoproterozoic (ca. 970–800 Ma) arc system of the Taimyr orogen evolved on the active margin of the SC and probably extended along the periphery of Rodinia into Valhalla orogen of NE Laurentia. We also suggest the late Neoproterozoic (750–550 Ma) arc system could have been part of the Timanian orogen, which linked Siberia and Baltica at the Precambrian/Phanerozoic transition.

识别西伯利亚克拉通（Siberian Craton, SC）北缘周边新元古代（Neoproterozoic）地壳的克拉通亲缘性，对于阐明该克拉通的构造演化历程，以及将其纳入新元古代超大陆重建框架均具有关键意义。将新获取的碎屑锆石U–Pb–Hf数据与区域地质约束条件相结合的研究表明，泰梅尔造山带（Taimyr orogen）内可识别出特征鲜明的新元古代弧相关岩浆带。源自970~800 Ma弧相关岩系的沉积岩蕴含大量太古代（Archean）与古元古代（Paleoproterozoic）碎屑物质，这一特征与西伯利亚克拉通的属性一致。来自较年轻寒武纪（Cambrian）沉积岩的720~600 Ma弧相关锆石群体，同时伴随有外来的中元古代（Mesoproterozoic）新生锆石群体，以及古老弧相关岩系的侵蚀产物。尽管如此，诸多证据均表明这两条弧带均广泛改造了西伯利亚克拉通的基底组分。研究认为，泰梅尔造山带的早新元古代（约970~800 Ma）弧系统形成于西伯利亚克拉通的活动大陆边缘，并可能沿罗迪尼亚超大陆（Rodinia）的边缘延伸至东北劳伦大陆（Laurentia）的瓦尔哈拉造山带（Valhalla orogen）。本研究同时提出，晚新元古代（750~550 Ma）弧系统可能属于蒂曼造山带（Timanian orogen）的组成部分，该造山带在前寒武纪-显生宙过渡时期连接了西伯利亚与波罗的古大陆（Baltica）。