Geomagnetic polarity transitions recorded in the Miocene lavas of the Wuyu basin, Tibet

Geomagnetic polarity transitions were the most important phenomena in the study of the geomagnetic field evolution and the earth＇s deep interior dynamics. The Miocene postcollisional ultrapotassic-potassic rocks are widely distributed in the Lhasa Block of southern Tibet. Paleomagnetic studies on the Wuyu Formation indicated that these volcanic rocks recorded the C5Bn.2n-C5Bn.lr and C5ACr-C5ACn geomagnetic polarity transitions. The virtual geomagnetic poles （VGPs） of these two polarity transitions were located in the Atlantic and the central Pacific, respectively. Due to data scarcity, it remains unclear whether VGP paths of Miocene geomagnetic polarity transitions were longitudinal preference and/or 90° away from the sampiing sites.