LA-ICP-MS zircon U-Pb age of the tuffs from the Luobusha conglomerates in southeast Tibet and its implications

The age of the felsic tuff interbedded with the Luobusha conglomerates in western Zetang County is reported for the first time in this paper. LA-ICP-MS zircon U-Pb analysis shows that the tuffs were formed at 18.7±0.2Ma, and hence the time of the initial deposition should be about 20Ma, whereas the LA-ICP-MS zircon U-Pb age of granite underlying the Luobusa conglomerates is 29.9±0.4Ma. The existence of the tuff documents a volcanic activity developed at 18.7±0.2Ma. In combination with geochronologic data from previous work, the authors hold that volcanic activities were developed all along the Yarlung Zangbo suture zone, meaning the re-activation of the suture zone, which is remarkably similar to the potassic-ultrapotassic volcanism along the Gangdise zone in time and space.