C) are recorded well in speleothems, giving high-resolution data that can show annual variation in temperature (oxygen isotopes primarily reflect rainfall temperature) and precipitation (carbon isotopes primarily reflect C3/C4 plant composition and plant productivity, but the interpretation is often complicated).By sampling along a dated transect of a speleothem, these isotope values and speleothem growth rates provide a paleoclimate records similar to those from ice cores.This makes the technique often disappointing for the experimentalists.One of the main challenge of the technique is the correct identification of the radiation-induced centers and their great variety related to the nature and the variable concentration of the impurities present in the crystal lattice of the sample.Unfortunately, not all the samples are suited for ESR dating: indeed, the presence of cationic impurities such as Mn, humic acids (organic matter), can mask the signal of interest, or interfere with it.Moreover, the radiation centers must be stable on geologic time, i.e., to have a very large lifetime, to make dating possible.
These indicators, alone and in conjunction with other climate proxy records, can provide clues to past precipitation, temperature, and vegetation changes over the last ~ 500,000 years.
However, "good samples" might be found if all the selection criteria are met.
Secondary deposits derived from concrete, lime, mortar or calcarious material as found on man-made structures outside the cave environment or in artificial caves (e.g.
Most other solution caves that are not composed of limestone or dolostone are composed of gypsum (calcium sulfate), the solubility of which is positively correlated with temperature.
Speleothems are studied as climate proxies because their location within cave environments and patterns of growth allow them to be used as archives for several climate variables.