Pub. date: 2008 | Online Pub. Date: April 25, 2008 | DOI: 10.4135/9781412963893 | Print ISBN: 9781412958783 | Online ISBN: 9781412963893| Publisher:SAGE Publications, Inc.About this encyclopedia
Climatic Data, Cave Records
Abbey E. Chrystal
CAVES HAVE PROVIDED climate researchers with several useful ways to learn about past climates. In caves that are connected to the surface, plant (particularly pollen) and animal remains allow scientists to study floral and faunal successions over time, which often reflect concurrent climate shifts. Cave deposits, collectively called speleothems (for example, stalagmites and stalagtites) provide interesting information that, though geochemical techniques are still being refined, promises a detailed and well-constrained record of past climate variability. Caves are commonly found in limestone (calcium carbonate, CaCO 3 ) bedrock settings. When precipitation moves through a soil horizon, it picks up dissolved carbon dioxide (CO 2 ) produced in organic decomposition, thereby becoming mildly acidic. The acidic groundwater then slowly dissolves CaCO 3 bed-rock, forming caves over time. Speleothems form when dissolved CaCO 3 precipitates from groundwater upon interaction with cave air. As groundwater carrying dissolved CO 2 and CaCO 3 reaches 2 ...