U series dating
Because these elements (and their isotopes) all have different half-lives, elements with longer half-lives will be present in greater quantities than those with shorter half-lives.
Therefore, when equilibrium is disrupted (for example when a mineral breaks down leading to gain or loss of uranium and/or thorium), we can calculate the degree to which equilibrium has been restored between parent and daughter isotopes.
This area is at the intersection of the southeastern edge of the Colorado Plateau with the Jemez lineament, a northeast-trending zone of volcanic activity over the last 4.5 Ma.
Travertine deposits occur in clusters near the Little Colorado River (LCR) and along fault lineaments overlying the Springerville-St.
Thus, the apparent ~70 ka cyclicity of travertine deposition appears to be due to a combination of increased climatically-modulated groundwater recharge during wet/glacial times and over-pressuring of the CO2/groundwater system due to the periodic influx of magmatically sourced fluids.
Dated travertines and basalts associated with elevated LCR gravel terraces in the region provide constraints on river incision and landscape denudation.
High CO2 springs and related travertine deposits of the Springerville area of east-central Arizona provide an exceptional field laboratory for understanding travertine-depositing spring systems.
U-series dating of travertines provides an opportunity to unravel paleohydrologic and neotectonic histories near the southeastern edge of the Colorado Plateau.
This travertine and CO2 system is bounded on the west by the Plio-Pleistocene Springerville volcanic field (SPV) which was active until 308 ka and on the east by the late Mio-Pleistocene Red Hill-Quemado volcanic field where volcanic activity continued until as recently as 71 ka.These elements are usually present in constant (equilibrium) amounts in a sample, as long as the system remains closed.A closed system is one in which there is no free exchange of elements in a material with the outside environment.Modern springs adjacent to the CO2 field are actively degassing CO2, have Cexternal values of 50%, concentrations of TDS up to 2538 mg/l, and are currently depositing minor volumes of travertine.3He/4He ratios from wells in the CO2 field and adjoining springs range up to 0.58 RA, indicating the presence of asthenospheric mantle-derived gases in modern spring waters (up to about 7% of the total helium).