The Structural Position and the Petrogeochemical and Petropaleomagnetic Characteristics of Volcanic Rocks from the Nilan Terrane (the Junction Zone between the Mongol-Okhotsk and Sikhote-Alin Orogens) and Geodynamic Conclusions

The results of structural, petrogeochemical, petro- and paleomagnetic studies of Mesozoic rocks from the Nilan terrane, which from the north adjoin the Paleozoic rocks of the Paukan block (52.0° N, 135.6° E), are presented. Jurassic and Triassic (?) complexly dislocated deposits of terrane are found to be fragments of the Middle–Late Jurassic accretionary complex with different concentration of older oceanic rocks and the oceanic plate with completely destroyed stratigraphy. Basic and intermediate volcanic rocks hosted within Jurassic and Triassic (?) sedimentary rocks of the terrane are of oceanic origin. Based on geochemical and paleomagnetic data, it is assumed that the volcanic rocks formed near the equator in geodynamic settings of the mid-ocean ridge and intraplate ocean islands.