Nuevas aportaciones a la palinología del Terciario de la Cuenca del Duero

Abstract

The present work describes the palinological study of the Torremormojón section (Falencia) of the upper Miocene of the Duero Basin. Folien analysis reveals a slight predominance of Gymnosperms over Angiosperms. Within these latter, two famihes, Arecaceae (= Falmae) and Fagaceae, are outstanding, followed in predominance by Ericaceae and Oleaceae {Fraxinus and Phillyrea). Regarding the pollen from sources other than trees, the Family Foaceae (= Gramineae) is noteworthy in the pollen spectrum, followed to a lesser extent by Amaranthaceae-Chenopodiaceae, wich are always present. Fteridophyta are very scarce and yet the presence of Zygnemataceae, Dinoflagellates and other non-pahnomorphic organic remains are very abundant. These data point to the existence at Torremormojon of a lake environment which underwent expansions and contractions possibly due to local chmatic changes. Such changes would have modified the plant layer, the warm and humid tertiary element alternating with the temperate Mediterrenean-like elements (humid or dry).