Paleotemperatures derived from

Paleotemperatures derived from noble gas analyses are potentially more meaningful than those from oxygen-deuterium analyses because the noble gas content is a direct measure of the temperature of the water at the time of infiltration rather than a complex function of geographic and meteorological factors as is the case with 2H and 180. Despite this potential superiority, few noble gas studies of water paleotemperatures have been published. Specifically, questions need to be answered relative... 

Johnsen S. J., Dahl-Jensen D., Dansgaard W., and Gundestrup N. (1995) Greenland paleotemperatures derived from GRIP bore hole temperature and ice core isotope prohles. Tellus 47B, 624-629. 

Talma, A. S. and Vogel., J. C., 1992, Late quaternary paleotemperatures derived from a speleothem from Cango Caves, Cape Province, South Africa Quat. Res. 37 203-213. 

Stute, M., Schlosser, P., Clark, J. F., and Broecker, W. S. (1992). Paleotemperatures in the southwestern United States derived from noble gases in ground-water. Science 256,1000-1003. 

Stute M., Clark J. F., Schlosser P., Broecker W. S., and Bonani G. (1995) A 30,000 yr continental paleotemperature record derived from noble gases dissolved in groundwater from the San Juan Basin, New Mexico. Quat. Res. 43, 209—220. 

The temperature dependence of equilibrium isotope exchange in the calcite-water system has been intensively studied since Urey (1947) first suggested that the paleotemperature of the ancient oceans could be estimated by the 0-isotope distribution between seawater and the calcium carbonate precipitated from it. Urey et al. (1951) argued that O-isotope equilibrium between seawater and CaC03 was likely and support for this idea has come from the close agreement between the CaC03-H20 isotopic fractionation observed in natural systems and those derived from both thermodynamic calculations and laboratory experiments (e.g. Epstein et al., 1951, 1953 Emiliani, 1955 O Neil et al., 1969 O Neil et al., 1975). 

The identification of paleo anomalies in heat flow and geothermal gradients supports the identification of former hydrodynamic and migration conditions in a basin. Information on paleotemperatures can be derived from fluid inclusion data (Roedder, 1984), apatite fission track analysis, biomarkers and vitrinite reflectance data (Allen and Allen, 1990 Naeser and McCulloh, 1989). 

The possibility to derive paleotemperature records from dissolved noble gases in ground water, on the basis of the temperature dependency of their solubilities in water, is probably the application of noble gases in subsurface hydrology that received most attention in recent years. A large number of ground-water studies over the past 40 years used this approach to reconstruct paleoclimate conditions. 

Heaton THE, Talma AS, Vogel JC (1986) Dissolved gas paleotemperatures and 0 variations derived from ground water near Uitenhage, South Africa. Quat Res 25 79-88 Heaton THE, Vogel JC (1979) Gas concentrations and ages of ground waters in Beaufort Group sediments, South Africa. Water SA 5 160-170... 

Diffusive information loss limits resolution of borehole-derived paleotemperatures. A borehole temperature profile from central Greenland reveals information about the previous day, the previous year, the previous decade, the Little Ice Age of one to a few centuries ago, the warmth in the middle Holocene a few millennia ago, and the cold of the ice age centered about 20-30 thousand years ago (Alley and Koci 1990 Cuffey et al. 1992, 1994, 1995 Firestone 1995 Johnsen et al. 1995 Cuffey and Clow 1997 Dahl-Jensen et al. 1998). 

Another important aspect of ground-water paleoclimate records is the possibility to relate the absolute temperature estimates obtained from the noble gases to the relative temperature indicator provided by the stable isotope composition of the water (5 0 and 5 H). In most noble gas paleotemperature studies, stable isotopes ratios have also been determined, and in many cases clear relationships between the two climate proxys were found (e.g., Heaton et al. 1986 Stute and Deak 1989 Beyerle et al. 1998 Huneau et al. 2001). Such relationships offer the chance to derive local slopes for the long-term S O/T-relationship. 

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