The bioerosion trace fossils are described from the Pliocene cropping out at the Agua Amarga Subbasin (Betic Cordillera, Almería Province, SE Spain). They are associated with limestone clasts (pebbles and cobbles) and molluscs constituting a shallow marine conglomerate and an overlying composite shell bed that were deposited in a shallow marine setting. The ichnotaxa include borings produced by sponges (Entobia cateniformis, E. geometrica, E. laquea, E. form A and E. form B), bivalves (Gastrochaenolites torpedo, and G. lapidicus) and polychaete annelids (Caulostrepsis taeniola, Meandropolydora ?decipiens, M. cf. elegans, and M. cf. sulcans). Encrustations by bryozoans and tube annelids are also present. The bioerosion trace fossils assemblages from the conglomerate and the shell bed can be ascribed to the Entobia subichnofacies, which is typical of Neogene rocky-shore settings. Bioerosion analysis allows improved interpretation of palaeoenvironmental (ecological and depositional) conditions i.e. hydrodynamic energy, rate of sedimentation, and exposure time, in the Agua Amarga Subbasin during the Pliocene.

We report high-resolution macroscopic charcoal, pollen and sedimentological data for Agua Caliente, a freshwater lagoon located in southern Belize, and infer a late Holocene record of human land-use/climate interactions for the nearby prehistoric Maya center of Uxbenká. Land-use activities spanning the initial clearance of forests for agriculture through the drought-linked Maya collapse and continuing into the historic recolonization of the region are all reflected in the record. Human land alteration in association with swidden agriculture is evident early in the record during the Middle Preclassic starting ca. 2600calyrBP. Fire slowly tapered off during the Late and Terminal Classic, consistent with the gradual political demise and depopulation of the Uxbenká polity sometime between ca. 1150 and 950calyrBP, during a period of multiple droughts evident in a nearby speleothem record. Fire activity was at its lowest during the Maya Postclassic ca. 950–430calyrBP, but rose consistent with increasing recolonization of the region between ca. 430calyrBP and present. These data suggest that this environmental record provides both a proxy for 2800years of cultural change, including colonization, growth, decline, and reorganization of regional populations, and an independent confirmation of recent paleoclimate reconstructions from the same region.

[EN] In this PhD thesis, we contribute to a more detailed knowledge of the biogeography of coccolithophores in one of the most productive marine ecosystem on earth: the Peru-Chile Current realm, which extends along the west coast of South America. | [ES] En esta tesis se contribuye a un mayor conocimiento de la biogeografía de los Cocolitóforos en uno de los ecosistemas marinos más productivos de nuestro planeta: el sistema de corrientes de Perú- Chile, que se extiende a lo largo de la costa oeste de Suramérica.

The Regional Deep Cretaceous Aquifer (RDCA) is the principal groundwater resource in Syria. Isotope and hydrochemical data have been used to evaluate the geographic zones in terms of renewable and non-renewable groundwater and the inter-relation between current and past recharge. The chemical and isotopic character of groundwater together with radiometric ¹⁴C data reflect the existence of three different groundwater groups: (1) renewable groundwater, in RDCA outcropping areas, in western Syria along the Coastal and Anti-Lebanon mountains. The mean δ¹⁸O value (−7.2 ‰) is similar to modern precipitation with higher ¹⁴C values (up to 60–80 pmc), implying younger groundwater (recent recharge); (2) semi-renewable groundwater, which is located in the unconfined section of the RDCA and parallel to the first zone. The mean δ¹⁸O value (−7.0 ‰) is also similar to modern precipitation with a ¹⁴C range of 15–45 pmc; (3) non-renewable groundwater found in most of the Syrian interior, where the RDCA becomes confined. A considerable depletion in δ¹⁸O (−8.0 ‰) relative to the modern rainfall and low values of ¹⁴C (<15 pmc) suggest that the large masses of deep groundwater are non-renewable and related to an older recharge period. The wide scatter of all data points around the two meteoric lines in the δ¹⁸O-δ²H diagram indicates considerable variation in recharge conditions. There is limited renewable groundwater in the mountain area, and most of the stored deep groundwater in the RDCA is non-renewable, with corrected ¹⁴C ages varying between 10 and 35 Kyr BP.