麻山杂岩的形成与演化及其对佳木斯地块构造属性的制约

佳木斯地块是中国东北地区著名的晚泛非期高级变质微陆块，其基底组成及构造属性研究是重建中亚造山带东段构造格局和东北亚大陆演化过程的关键。本项目选择代表佳木斯地块基底的麻山杂岩为研究对象，开展岩石学、年代学、矿物学与元素-同位素地球化学的系统研究，旨在查明新元古代表壳岩的沉积时限、岩石组合和物源，确定新元古代正片麻岩的原岩时代、成因和构造背景，明确晚泛非期麻粒岩相变质作用的峰期时间和P-T-t轨迹，进而反演麻山杂岩的形成与演化历史。结合区域古地磁、古生物和增生杂岩资料以及全球超大陆重建的最新认识，最终揭示佳木斯地块的构造属性及其与Rodinia超大陆和东冈瓦纳大陆的时空演化联系。该项研究不仅可以为揭示中亚造山带东段构造演化模式提供关键证据，而且对理解增生型造山带的地壳增生及岩石圈深部作用过程具有重要意义。

Jiamusi Block is the famous late Pan-African high-grade metamorphic microcontinent in NE China, the research on its basement composition and tectonic affinity is the key to reestablish the tectonic frame of the eastern Central Asian Orogenic Belt (CAOB) and the evolution processes of the Northeast Asian continent. This project will take the Mashan Complex (i.e., the basement of the Jiamusi Block) as the research object, and conduct a systematical study of petrology, geochronology, mineralogy and element-isotope geochemistry, in order to 1) investigate the depositional ages, rock associations and provenance of the Neoproterozoic supracrustal rocks; 2) determine the protolith ages, petrogenesis, and tectonic settings of the Neoproterozoic orthogneisses; 3) ascertain the peak timing and P-T-t path of the late Pan-African granulite-facies metamorphism, and then establish the formation and evolution history of the Mashan Complex. In combination with regional data of paleomagnetism, paleontology, and accretionary complexes, as well as the latest knowledge of global supercontinent reconstruction, this project will finally reveal the tectonic affinity of the Jiamusi Block and its temporal-spatial evolution relations with the Rodinia supercontinent and East Gondwana continent. This project not only provides vital evidence for revealing the tectonic evolution model of the eastern CAOB, but also has important significances for understanding the crustal growth and deep processes of the lithosphere in the accretionary orogenic belt.