| 释义 |
speleothem Geol.|ˈspiːliːəʊθɛm|
[f. Gr. σπήλαιον cave + θέµα that which is laid down, deposit.]
Any structure which is formed in a cave by the deposition of minerals from water, e.g. a stalactite, stalagmite, etc.
1952G. W. Moore in Nat. Speleol. Soc. News June 2/1 In an effort to relieve the ambiguities of ‘formation’, the term speleothem is proposed... It is suggested that the word be used as a general term for secondary mineral deposits formed from water in caves, such as stalactites, helictites, rimstone terraces. 1968Nature 6 July 49/1 Temperature dependent fluctuations in the 18O/16O composition of calcite deposited on speleothems could be used to fill this gap in the present understanding of past climates. 1976W. B. White in Ford & Cullingford Sci. of Speleology viii. 271 There is a competition between shapes guided by the flow path of the solution and shapes guided by the particular mineral and its crystal habit. This gives rise to two broad classes of speleothems, drip⁓stone and flowstone forms and erratic forms. 1980Cambr. Encycl. Archaeol. 53/1 Methods involving the measurement of different isotopes are being widely applied to derive long climatic records from ice cores, cave deposits like stalagmites (speleothems) and tree rings. |