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10.1016/j.quascirev.2013.12.002 Vallparadís is one of the best calibrated and most accurately dated archaeological sites from the European Early Pleistocene. Chronological analyses combined with palaeomagnetism, ESR-U/series and OSL, and the biochronology of macro- and micromammals are fully consistent and situate the site just above the upper limit of the Jaramillo subchron. In this article we compare the mandibular first molar (m1) of individual adult specimens of Mimomys savini recovered from level 10 (EVT7) at Vallparadís with specimens from the stratigraphic sequence at Gran Dolina (Atapuerca), Fuente Nueva 3 and Barranco León D (Orce). This comparison allows us to chronostratigraphically relate level 10 at Vallparadís with level TD5 at Gran Dolina and to fix the former's chronology to around 0.98¿0.95 Ma (MIS 27) and, therefore, prior to level TD6 in which fossil remains of Homo antecessor were recovered. The chronology of Vallparadís and the set of contemporary palaeoclimatic proxies regarding the Iberian Peninsula strengthen the hypothesis that hominins continuously populated Europe, at least in Iberia, throughout the late Early Pleistocene between the Jaramillo subchron and the Matuyama¿Brunhes boundary by overcoming the climatic fluctuations and changes to the landscape that occurred during this period.

This paper presents the existing differences between the evolution of the Holocene landscape of the Southeastern and Southwestern areas of the Iberian Peninsula. Moreover, some palaeoenvironmental characteristics of OIS 4 and OIS 3 of the western Andalusia appear. The five presented sequences have been analyzed from palynological and geomorphological point of view. The obtained results show that during the Holocene no significant forest cover existed in the eastern area and that the different phases identified mainly show an alternation of shrub and steppe communities, taking place during the fifth millennium a radical transformation of the landscape and the definitive establishment of the semi-desert conditions that are registered at the present time. In the western area the evolution of the landscape is determined basically by the changes of geomorphological conditions of the coast and the marshland zones of the Guadalquivir and the Tinto-Odiel systems, registering diverse moments of increase of the aridity conditions, without remarkable changes in the vegetal landscape. Sequences obtained do not provide evidence of indicators of human intervention that might be clearly attributable to the pattern of human activities established in the area until a the two millennium ago.

Con la aplicación del método semiempírico CND0/2 (CompletNeglect of Differential Overlap in Two-electron Integrals and in Normalization), se han calculado las curvas de energía potencial, en función de la distancia de enlace correspondientes a los poliedros aniónicos: (SiO4)4-, (AlO4)5- (AlO5)7 y (AlO6)9, así como las correspondientes a formas polimerizadas del tipo: (Si2O7)6 (Si2O6)4-, (Si2o3)2-, (Si8O10)8-, (Al207)8- (Al2O6)6- y (Al2O5)4-.Dado el estado actual más bien precario de conocimientos sobre los efectos y relaciones que rigen la dinámica de redes cristalinas minerales, el tipo de curvas potenciales obtenidas establecen un modelo suficientemente expresivo para comprender que la estabilización del proceso de polimerización de grupos (SiO4) en la estructura de silicatos no es independiente de la totalidad de factores cristaloquímicos inherentes a este tipo de estructuras. Por otra parte, ponen también de manifiesto las serias limitaciones que pueden concurrir en la aceptación de un modelo estrictamente molecular en la tarea de predecir los modos vibracionales de las estructuras de silicatos.Finalmente, se han calculado para los grupos aniónicos: (SiO4)4-, (AlO4)5, (AlO5)7- y (AlO6)6- los valores correspondientes a la constante de fuerza k ("stretching constant force").

Se estudia la hidrólisis de olivino de composición: SiO4 Mg1,8Fe10 a 100ºC en función de soluciones a distintos pH: 1,6, 3,18, 3,55, 3,65 y 7,9. Los resultados obtenidos permiten un ajuste según funciones exponenciales (cte. tw) donde w se aproxima 1/2. Se establece un modelo para explicar el proceso de disolución de cationes Mg24 en la superficie del olivino.