U-series dating of the travertine depositing near the Rongma hot springs in northern Tibet, China, and its paleoclimatic implication

Abstract

High resolution age data obtained by travertine dating is necessary for the reconstruction of paleoclimate and palaeohydrology near Rongma hot springs in northern Tibet. U-series dating of a travertine cone depositing in the study area was used. The results show that the U contents of the travertine samples range from 0.298 to 1.363 ppm, and the 234U/238U is in the rage of 1.475–1.700, indicating that the deposition of travertine near the Rongma hot springs is stable and continuous. The age of the travertine samples ranges from 11,500 to 4600 a, corresponding to the first stage of MIS 1. Combination of the first stage of MIS with the effect of monsoon climate of the Indian Ocean in the same period implies a warm and humid climate during the deposition of the travertines in the study area. The U-series age range in the Rongma hot springs area is coincident with that of the travertine in southern Tibet. The age data detected from travertine cone help in understanding the evolution of hydrogeology of the hot spring area. High resolution age data must be acquired before travertine can be confidently used as a paleoclimatic archive.