Estacionalidad de la laminación espeleotémica de las Cuevas de Ortigosa de Cameros (La Rioja): aproximación experimental

Abstract

Monitoring of both carbonate precipitation process and environmental parameters inside two caves in Ortigosa de Cameros (La Rioja, Spain) has allowed us to establish the seasonality of speletohem lamination in these caves. Temperature record shows a minimum in March-June and a maximum in August with little oscillation (< 1ºC). Drip water flow is maximum in autumn and spring. The carbonate record displays white porous laminae (WPL) and dark compact laminae (DCL) of seasonal origin. DCL are organic matter rich and form in high drip water flow periods, when soil organic matter is flushed into the caves. Stable isotope analyses of drip water (δ18O and δD) and carbonate (δ18O and δ13C) confirm the seasonal pattern: δ13C minimus correspond to the warm seasons (WPL) while δ18O pattern can be explained on the basis of the corresponding drip water δ18O variations