Position of the Lhasa Terrane and Two‐Stage Crustal Shortening During the India–Asia Collision

Abstract The paleolatitudinal change of the Lhasa Terrane is critical for estimating the timing of the India–Asia collision and associated syn‐to post‐collisional crustal shortening, but its paleoposition is highly debated. Here we present integrated geochronologic and paleomagnetic results from the Lower Eocene Nianbo Formation in the Linzhou Basin. Two SIMS U−Pb zircon ages of 54.59 ± 0.68 Ma and 53.97 ± 0.43 Ma were obtained from the strata. The magnetostratigraphy spans chrons C24r–C23r, estimating deposition from ∼55.37 to ∼52.54 Ma. Paleomagnetic data yield a paleopole of 74.1°N, 270.1°E ( A 95 = 2.2°) for the Lhasa Terrane, corresponding to a paleolatitude of 14.1 ± 2.2°N. Synthesis of published paleomagnetic data reveals that the Lhasa Terrane migrated from ∼10°N (Late Cretaceous) to ∼14°N (Early Eocene), and reached ∼20°N at ∼50 Ma. This two‐stage latitudinal shift implies two‐stage crustal shortening, which might relate to the Tethyan Himalaya–Lhasa collision and the India–Asia collision, respectively.