Wet–dry seasonal and spatial variations in the δ13C and δ18O values of the modern endogenic travertine at Baishuitai, Yunnan, SW China and their paleoclimatic and paleoenvironmental implications

Equilibrium vs. kinetic fractionation of oxygen isotopes in two low-temperature travertine-depositing systems with differing hydrodynamic conditions at Baishuitai, Yunnan, SW China

“…The seasonal variation of carbon and oxygen isotopes (d 13 C and d 18 O) may synchronize with biannual lamination, i.e., low in summer and high in winter, which has been widely observed in meteogene travertine (Pentecost, 1995) or tufa (Matsuoka et al, 2001;Ihlenfeld et al, 2003;Kano et al, 2003Kano et al, , 2007Hori et al, 2009;Brasier et al, 2010) and thermogene travertine (Pentecost, 1995;Liu et al, 2003Liu et al, , 2006aSun and Liu, 2010). Travertine and tufa have unique advantages in providing high-resolution (up to seasonal, monthly or even daily) paleoclimate information due to the high growth rates of many deposits (mm to cm/year) (Kano et al, 2003;Liu et al, 2010).…”

“…In a previous study, Liu et al (2006a) demonstrated that there was regular seasonal variation of the C and O isotope ratios in a modern laminated travertine deposited in a sample canal between May 1998 and November 2001. Sun and Liu (2010) provided more detailed temporal and spatial data on the same travertinedepositing canal. In the present study, the oxygen isotopic fractionation under two different sets of hydrodynamic conditions (a fast flow canal system and a slow flow pools system) is investigated by the method of placing plexiglass substrates .…”

Geochemistry and Stable Isotopes of Travertine from Jordan Valley and Dead Sea Areas

“…Such ratios provide an expanded scale for the comparative small differences observed [42]. For travertine, fractionation of carbon and oxygen isotopes is of particular interest.…”

“…They provide information about the carbon dioxide source, the physio-chemical conditions of the precipitation event (rate and temperature), and the influence of metabolic processes. In favorable circumstances, they provide information about the temperature at which deposition occurred, and assist in radiometric dating [42].…”

“…As the lithosphere water exchanges oxygen atoms with the dissolved carbon dioxide, and where equilibrium is established, the difference between the ratio of oxygen isotopes in carbonates and depositing water can be used to estimate past water temperatures, assuming that the fluid source has not changed through time. Information can also be obtained on rates of water evaporation with time [8,42].…”