A first last glacial maximum stalagmite record from southern Portugal

• Autor(es): Veiga-Pires, C. ; Ghaleb, Bassam ; Hélie, Jean-François ; Moura, Delminda ; Luis, Joaquim ; Hillaire-Marcel, C.
• Data: 2011
• Identificador Persistente: http://hdl.handle.net/10400.1/3236
• Origem: Sapientia - Universidade do Algarve
• Tipo de Documento: Outro
• Idioma: Inglês

Descrição

A newly launched research program permitted the sampling of speleothem deposits in the Algarve area (Southern Portugal). Unfortunately, this stalagmite yielded very small amounts of U (~ 20 ppb), making the setting of a U-series chronology difficult due to both the relative importance of a detrital contaminating fraction and the lack of precision on overall 230Th measurements. Nevertheless, based on the top and most recent sample, we extracted a first order estimate for the 230Th/232Th ratio of the contaminating fraction and for its 234U/232Th and 238U/232Th ratios as well, assuming a secular equilibrium between 234U and 238U in this fraction.