Radiocarbon-Dated Molluscan Successions from the Holocene of Central Spain
1991; Wiley; Volume: 18; Issue: 4 Linguagem: Inglês
10.2307/2845483
ISSN1365-2699
Autores Tópico(s)Pleistocene-Era Hominins and Archaeology
ResumoThe molluscan successions from thick calcareous sediments exposed in the Rio Henares valley near Baides, central Spain, have been analysed. The main sequence com- prises a thick unit of bedded silts, with occasional interbed- ded gravels and sands. These silts accumulated in a marsh on the river floodplain between 9940 ? 120 BP and 6210 ? 85 BP. Pollen spectra from this period are completely dominated by Pinus which reaches frequencies of -80%. The silts have yielded a hygrophilous fauna which includes several taxa which today are scarce or very local. These include Vallonia enniensis (Gredler) and towards the top Vertigo moulinsiana (Dupuy) and V. angustior Jeffreys. This unit is overlain by tufa containing an aquatic communi- ty that includes some brackish elements. A date of 5160 ? 90 BP has been obtained from charcoal from a palae- osol, representing a pause in tufa growth when the surface was invaded by species of dry ground. The tufa is overlain by slope deposits containing re-worked elements from the tufa, mixed with a xerophilous fauna that includes Zebrina detrita (Muller) and Orculella bulgarica (Hesse). The latter species is particularly noteworthy because it is only known as fossils or from dead shells from a few scattered localities in southern Europe, Turkey and Soviet Asia. The compara- tively young date of 2640 ? 70 BP from this sequence sug- gests that it may well persist in this part of Spain. A further section, immediately south of the others, represents a much drier facies with a higher proportion of xerophiles including
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