How does speleothem (cave deposit) data factor into the study of global climate change?

Question

I'm somewhat familiar with the study of tree rings, ice cores and coral, but was wondering how this line of study can be useful.

Answer 1

They are made from calcium carbonate precipitated out of solution.  The carbon atoms come from CO2 respired by plant roots and soil organisms that feed on dead plant matter.  The isotope ratio of carbon atoms (amount of 13C/12C) is related to plant responses to water stress for C3 plants (most plants), and there is big change in 13C content when C4 plants occupy an area (C4 plants are adapted to hot conditions or low CO2 environments).  The oxygen in the CaCO3 ultimately traces back to water that fell at the site where the dissolved carbonates entered the groundwater.  The oxygen isotope ratio (amount of 18O/16O) depends on a number of factors related to climate and geography, including temperature.

Answer 2

I know at least part of the answer. NOT the part Tik knows.

The Carroll Cave Conservancy has allowed Ancient weather studies to be conducted on Carroll cave speleothems. As the formations are forming There are floods and droughts. The floods cover the formations with silt/mud. The formation is always growing so clean layers form over muddy layers. If you cut a Stalagmite in two you will see rings like a tree. There are ways to date the rings  (not my expertise).

Studies like this and others is what we support at C.C.C.