Cave temperature effect

Dvorsky, R., Sevcik, J., Caves, L. S. D., Hubbard, R.E., and Verma, C. S. (2000) Temperature effect on protein motion a molecular dynamics study of RNAase-Sa/. Phys. Chem. B 104, 10387-10397. 

The second step is to establish whether the calcites were deposited in isotopic equilibrium with the waters from which they are derived. During slow degassing, the isotopic fractionation between the aqueous and solid phases is controlled indirectly by cave temperature under equilibrium conditions. However, under an evaporative cave regime or rapid crystallisation, the isotopic fractionation is modulated by kinetic effects which inhibit isotopic equilibrium between the calcite and the drip waters (Hendy, 1971). 

Two features in caves facilitate the use of stable isotopes as a palaeoarchive (1) cave air temperatures remain relatively constant throughout the year and are similar to the mean annual temperature above the cave. (2) In cool temperate climate regions, cave air is characterized by very high humidity that minimizes evaporation effects. Interest in speleothems as recorders of continental palaeoenvironments has increased considerably in recent years. The potential of speleothems as climate indicators was first discussed by Hendy and Wilson (1968) followed by Thompson et al. (1974). These early investigators already recognized the complexity of cave carbonate iso-... 

Figure 2. Effects of different parameters on cave calcite growth rate A) precipitation rates for vmious film thicknesses (d in cm die thicker line represents average film thickness of 7.5 cm Baker and Smart, 1995) as a function of [Ca ] in the water film (T = 10°C, cavepCOz = 3x10" atm) B) precipitation rates (widi d = 0.01 cm and cave pCOt = SxlO atm) for various temperatures (in °C) C) precipitation rates for various cave pC02 levels (in 10 atm) (d = 0.005 cm, T = 10°C) D) values of the kinetic constant a as a function of temperature for different film diicknesses (d in cm)(cavepCO = 3x10 atm). All figures after B er et al. (1998).

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