En la cordillera de Talamanca los productos del magmatismo se encuentran ampliamente distribuidos, y corresponden con episodios intrusivos y extrusivos del Neógeno y del Cuaternario. En general es posible reconocer tres fases magmáticas: 1) Vulcanismo anterior al Mioceno Superior, de unos 17 a 11 millones de años atrás; 2) Plutonismo durante el Mioceno Medio-Superior, entre 12,5 y 7,5 millones de años, conocido como Grupo Intrusivo de Talamanca o Granito-Gabro de Talamanca; 3) Pulsos magmáticos post-intrusivos del Neógeno al Cuaternario, cuyo rango temporal se extiende entre 5 y 2 millones de años. Por primera vez se propone una diferenciación del magmatismo post-intrusivo en tres unidades, separables por aspectos petrográficos: a) Unidad Kámuk, constituida por andesitas con plagioclasa de tipo labradorita y ocasionalmente con ortopiroxeno; b) Unidad Dúrika, definida por plagioclasa de tipo andesina y biotita como fenocristal ferromagnesiano predominante; c) Unidad Río Lori, cuyos productos no fueron recolectados, pero con base en trabajos previos se caracteriza por la presencia de cuarzo, anfíbol y biotita. Se realiza además una contribución a la cartografía geológica de la cordillera de Talamanca, con una descripción geológica de las cimas de Cuericí, Ena, Dúrika, Utyum, Kámuk, fila Pittier y Echandi. También se presentan nuevos datos sobre la geología del cerro Chirripó.

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The Atlantic coast of Galicia (NW Spain) is a high‐energy environment where shingle beaches are currently developing. These coarser sediments alternate with sandy deposits which are also considered as beaches typical of a low‐energy environment. The physical association of both types of sediment with contrasted sedimentary significance raises problems of interpretation. The study of four outcrops of fossil aeolianites on this coast has allowed us to reconstruct their evolution from the end of the Upper Pleistocene to the present day. Their chronology, estimated by optically stimulated luminescence between 35 and 14 ky at the end of the last glaciation (MIS2), coincides with a local sea level 120 m below the present one. This implies a coastline shifted several kilometres from its current location and the subaerial exposure of a wide strip of the continental shelf covered by sands. The wind blew sand to form dunes towards the continent, covering the coastal areas, which then emerged with no other limitation than the active river channels. Sea‐level rise during the Holocene transgression has progressively swamped these aeolian deposits, leaving only flooded dunes, relict coastal dunes and climbing dunes on cliffs up to 180 m high. The aeolian process continued as long as there was a sandy source area to erode, although accretion finished when the sea reached its current level (Late Holocene). Since then, the wind turned from accretion to erosion of the dunes and sand beaches. This erosion exposes the older shingle beaches (probably of Eemian age) buried under the aeolian sands, as well as old, submerged forest remains and megalithic monuments. The destruction of sand beaches and dunes currently observed along the Galician coast is linked, according to most researchers, to anthropogenic global warming. However, their management should consider these evolutive issues.

Granite massifs often contain caves, with dimensions ranging from a few meters up to 1,000 m, also referred to as pseudokarst. The speleothems in such caves are mostly composed of either Si-rich (commonly opal-A) or Al-rich authigenic mineraloids. Whereas the formation and geochemical composition of opal-A biospeleothems have been studied and are fairly well understood, knowledge on the Al-rich analogues is scarce. This work reports for the first time a study on the composition, accretion process, age and growth rate of an Al-rich speleothem type flowstone from the A Trapa Cave System (Galicia, NW Spain), developed in a granite cave. To understand the growth process, trickling water was analyzed and the deposition environment inside the cave was characterized. We found that the speleothems are alternating Si- and Al-rich layered deposits formed between 1,635 ± 75 and 1,243 ± 58 cal BP by percolating water that carries underground mineral grains, dissolved ions, and organic matter from soil and the weathered bedrock above the cave.

Este trabajo establece la edad de un afloramiento de depósitos fluviales situados en la desembocadura actual del Río Ulla en la Ría de Arousa (Galicia, NO de España), a +40 m y +30m sobre el nivel del mar actual. Los depósitos están formados por materiales siliciclásticos de tipo trenzado (braided). Aunque conocidos desde hace mucho tiempo, no se había determinado nunca su edad, considerándose sucesivamente desde finiterciaria a cuaternaria e incluso material indiferenciado holoceno. Utilizando la técnica de luminiscencia ópticamente estimulada (OSL) se ha calculado una edad de enterramiento para los granos de cuarzo incluidos en el sedimento de 180 ka para el nivel inferior y entre 70 ka y 60 ka para los niveles superiores. La cronología aquí establecida es coherente con la obtenida para otros depósitos fluviales estudiados en la costa gallega y del norte de Portugal.