【摘要】 中国东北地区古亚洲洋与古太平洋构造叠加与转换的过程存在着很大的争议，而位于吉黑东部地区的吉林-黑龙江高压变质带记录了这一地质过程。本文针对依兰和萝北地区黑龙江杂岩开展了岩石学、地球化学和LA-ICP-MS锆石U-Pb同位素定年的专项工作，结合吉黑高压带研究最新进展，为探讨吉黑东部地区两大构造域叠加与转化过程提供关键证据。地球化学研究表明依兰地区的蓝片岩原岩为亚碱性玄武岩，形成于洋岛环境。LA-ICP-MS锆石U-Pb分析分别获得了依兰地区251±2.7Ma和268±2.5Ma的蓝片岩原岩年龄和260±12Ma和251±4Ma的绿片岩原岩年龄，及萝北地区259±3.1Ma、264±13Ma的角闪石片岩和钠长石角闪石片岩的原岩年龄。针对吉黑高压带中变质单矿物Ar-Ar年龄统计显示，变质单矿物具有～185Ma峰期年龄，应代表黑龙江蓝片岩相变质作用的时代。上述研究揭示了佳木斯与松辽地块之间的吉林-黑龙江洋的打开时间为中二叠世至晚二叠世(268～251Ma),闭合时间发生在早侏罗世(峰期185Ma)。吉林-黑龙江洋具有自西向东渐进式闭合、消亡的趋势，导致张广才岭杂岩(260～194Ma)早于黑龙江杂岩(256～185Ma)形成和就位。早侏罗世(194～185Ma)张广才岭杂岩带率先就位于松辽地块东缘，早-中侏罗世之后(～185Ma)黑龙江蓝片岩带就位于佳木斯地块西缘。早侏罗世(194～185Ma)为吉黑高压带形成与就位时代，也是古亚洲洋闭合和古太平洋俯冲启动的关键地质时期，即两大构造域叠加与转换的时代。更多还原

【Abstract】 There is considerable controversy over the formation and evolution process of the Jilin-Heilongjiang Ocean in Northeast China. This geological process is recorded by the Jilin-Heilongjiang high-pressure metamorphic belt located at the easternmost end of the Central Asian Orogenic Belt. To address this issue, we investigated the Heilongjiang Complex exposed in the Yilan and Luobei regions using geological and geochemical analyses combined with laser ablation inductively coupled plasma mass spectrometry zircon U-Pb isotopic dating. Our geochemical studies indicate that the protoliths of the Yilan blueschist consist of subalkaline basalt formed in an ocean island environment. The zircon U-Pb analyses yielded protolith ages of 251±2.7Ma and 268±2.5Ma for blueschist, and 260±12Ma and 251±4Ma for greenschist in the Yilan area. Additionally, protolith ages of 259±3.1Ma and 264±13Ma were obtained for amphibole schist and albite-amphibole schist in the Luobei area. After statistical analysis of the Ar-Ar ages of metamorphic single minerals in the Jilin-Heilongjiang high-pressure belt(Ji-Hei HP belt), it was found that metamorphic single muscovite has an isotopic age peak of 185Ma, representing the time of the blueschist-facies metamorphism in Heilongjiang. Our findings indicate that the opening of the Jilin-Heilongjiang Ocean occurred during Middle Permian to the Late Permian(268～251Ma) and its subduction occurred at Early Jurassic(～185Ma). The results of this study indicate that the opening of the Jilin-Heilongjiang Ocean, which developed between the Jiamusi and Songliao terranes, occurred during the Middle to Late Permian(268～251Ma) and closed during the Early Jurassic(peak age of 185Ma). The Jilin-Heilongjiang Ocean exhibits a trend of progressive closure and disappearance from west to east, which resulted in the formation and emplacement of the Zhangguangcai Range Complex(260～194Ma) earlier than the Heilongjiang Complex(256～185Ma).The Zhangguangcai Range Complex Belt was first located on the eastern edge of the Songliao Block during the Early Jurassic(194～185Ma), and after the Early and Middle Jurassic(～185Ma), the Heilongjiang Complex was located on the western edge of the Jiamusi Block. The Early Jurassic(194～185Ma) was the era of the formation and positioning of the Jilin-Heilongjiang high-pressure metamorphic belt, and also a crucial geological period when the Paleo-Asian Ocean closed and the Paleo-Pacific subduction was initiated, marking the superposition and transformation of the two major tectonic domains.更多还原