The Wenduermiao Group consisting of mainly submarine volcano-sedimentary rocks with low to middle metamorphic grade outcrops around Zhurihe town located between Erlianhot and Jining cities. The Wenduermiao Group is characterized by having iron deposits or prospects, discontinuous ophiolite lenses and mineral assemblages formed under high pressure. All these geologic features have been regarded as evidences of existence of the Early Paleozoic submarine trench. The study on