张广才岭地体的构造属性及其形成动力学背景

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中图分类号：P54 文献标志码：A

Abstract： The extensive development of Permian to Jurassic magmatic rocks in the Zhangguangcai Terrane，Northeast China， provides important information for understanding the regional tectonic evolution. This study systematically summarizes the geochronological and whole-rock geochemical characteristics of 266-163 Ma magmatic rocks from this terrane，identifying four distinct episodes of magmatic activity： The 266 - 240 Ma magmatic activity is mainly composed of adakitic and I-type magmatic rocks，while the 229 - 210，209-185 and 184 -163 Ma magmatic activities are mainly composed of adakitic， I-type and A-type magmatic rocks. Based on analysis of magma sources and tectonic setings，combined with regional geological constraints，we propose that the tectono-magmatic history of the Zhangguangcai Terrane was primarily controlled by the evolution of the Heilongjiang Ocean.Specifically，westward subduction of the ocean beneath the terrane occurred during 266 - 210 Ma，followed by ocean closure during 210-180Ma ，which culminated in the final collision between the Jiamusi-Khanka block and the Songliao block. The obduction of residual oceanic crust during （204号 triggered tectonic exhumation and final emplacement of the Heilongjiang acretionary complex. The occurrence of a magmatic lull 240-230Ma ） is attributed to low-angle subduction of the Heilongjiang Ocean. Our findings indicate that the Zhangguangcai Terrane represents a combination of Late Paleozoic to Early Mesozoic accretionary complexes and continental arcs，rather than an ancient block with Neoproterozoic basement.

Key words： Zhangguangcai Terrane;Permian to Jurassc; Heilongjiang Ocean; magmatic phases;low angle subduction

0 引言

中国东北地区地处中亚造山带东段，位于古亚洲洋、蒙古一鄂霍茨克洋和古太平洋三大构造域的交汇与叠合部位[1-3]，复杂的构造演化历史，使其成为研究显生宙大陆地壳生长和构造体制转换的天然实验室。（剩余21390字）