1. Institute of Regional Geological Survey of Heilongjiang Province, Harbin 150080, China;
2. Department of Earth Science and Engineering, Taiyuan University of Technology, Taiyuan 030024, China;
3. College of Paleontology, Shenyang Normal University, Shenyang 110034, China

Huanerku rock association in the Dayangqi forest farm of the Da Hinggan mountains, is composed of amphibolite, meta-gabbro, peridotite and marble, which mainly occurr as NE-trending layers, lens and pieces. LA-ICP-MS zircon U-Pb dating of meta-gabbro samples from the Huanerku rock association yields ages of (696.8±2.9)Ma. Geochemistry analysis shows that the meta-gabbro samples are similar to N-type mid-ocean ridge basalts (N-MORB), and are also with some features of island arc tholeiite (IAT), indicating that the formation of the meta-gabbro was affected by subduction. Integrating the data from the Jifeng and Gaxian ophiolite in adjacent regions, the authors suggest that the Huanerku rock association has an affinity with ophiolitic melange. The meta-gabbro may represent the remnant of Late Neoproterozoic oceanic crust, indicating that there was a palaeo-ocean basin in the northern Da Hinggan mountains.