Discovery of the Upper/Lower Permian unconformity in the Rola Kangri junction zone, northern Tibet, China and its geological significance

The Rola Kangri junction zone is the westward extension of the Jinsha River junction zone. Through geological studies and investigations of the zone in recent years, many new discoveries have been made in the originally named Middle-Late Triassic Rola Kangri Group (T2-3rl) in this area and its neighboring areas. These discoveries indicate that this sequence of strata are an assembly of strata of many ages, which is not restricted to the Middle-Upper Triassic, and it has been found that the contact relationships between the Upper Permian and its underlying Carboniferous-Lower Permian are unconformable and that its contact relationships to its overlying Triassic are conformable. All these discoveries provide important information for reunderstanding the tectonic evolution in this area.