Browsing by Author "Ruiz, Francisco"
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- El contraste micropaleontológico de la Historia: el Lacus Ligustinus romanoPublication . Guerra, Liliana; C. Veiga-Pires, C.; González-Regalado, María Luz; Abad, Manuel; Toscano, Antonio; Muñoz, Juan Manuel; Ruiz, Francisco; Rodríguez Vidal, Joaquín; Cáceres, Luis Miguel; Izquierdo, Tatiana; Carretero, María Isabel; Pozo, Manuel; Monge, Guadalupe; Tosquella, Josep; Gómez, Paula; Romero, Verónica; Arroyo, Marta; Gómez, GabrlelDuring the Roman period (3rd century BC-5th century AD), the areas located near the present-day mouth of the Guadalquivir River were occupied by a lagoon with marine connection, according to the paleoenvironmental interpretation of benthic foraminiferal assemblages obtained in a core extracted in the Donana National Park. The inner zones of this lagoon were occupied by clayey tidal flats, which suffered the effects of a storm towards the end of the 1st century A.D. The comparison with the ostracod assemblages of the same core confirms this reconstruction and the paleogeographic data provided by various chroniclers, although these microcrustaceans better record the paleoenvironmental changes in these coastal sectors.
- Fingerprinting ceramics from the chalcolithic Santa Vitória Enclosure (SW Iberia)Publication . Marques, Rosa; Rodrigues, Ana Luisa; Russo, Dulce; Gméling, Katalin; Valera, António Carlos; Dias, Maria I.; Prudêncio, Maria I.; Basílio, Ana Catarina; Fernandes, Paula G.; Ruiz, FranciscoThe Santa Vitória Chalcolithic site (southern Portugal) prompts several questions related to the provenance and production technology of artefacts. Archaeological ceramics from two sections of Ditch 1 of the Santa Vitória site were studied by neutron activation analysis and X-ray diffraction for the first time, with the main goal of contributing to the contextualization of the artefacts and better understanding their production processes/technologies and the provenance of raw materials. The results point to a local production of ceramics, since their mineral phases reflect the geological contexts around the archaeological site. The mineralogical assemblage indicates a firing temperature below 850 ◦C. Iron is the better discriminator of ceramics from both sections, which could be related to the addition of different proportions of temper grains during the ceramics’ production. Although trace elements do not serve as discriminating geochemical indicators for the analyzed samples, they do imply a slightly higher heterogeneity in the composition of the ceramic paste from section 2. The negative Eu anomaly found in two samples is in accordance with the lower contents of Na2O, related to plagioclase weathering. Detailed studies on ceramics and potential raw materials are foreseen to assist in discussing the role of this Chalcolithic archaeological site at a regional level.
- From a marsh that was once sea: the geological evolution of Europe's largest biological reserve as told by its benthic foraminifera-a reviewPublication . González-Regalado, María Luz; Guerra, Liliana; Ruiz, Francisco; Veiga-Pires, Cristina; Abad, Manuel; Izquierdo, Tatiana; Vidal, Joaquín Rodríguez; Cáceres, Luis Miguel; Muñiz, Fernando; Carretero, María Isabel; Tosquella, Josep; Muñoz, Adolfo Francisco; Pozo, Manuel; Muñoz, Juan Manuel; Toscano, Antonio; Gómez, Paula; Romero, Verónica; Gómez, GabrielThis paper presents an updated list of benthic foraminifera found in brackish and marine (paleo-)environments of the Donana National Park (SW Spain) from the Lower Pliocene to the present-day. This list, based on published records, includes ninety-four species whose autoecology and temporal distribution in surface sections and continuous sediment cores allow us to infer the palaeogeographic evolution of this Biosphere Reserve over the last millions of years. During the Lower Pliocene, this area was occupied by a wide shallow bay with Nonion faba and Ammonia beccarii as the most representative species. During the Upper Pliocene, there was a transition to terrestrial environments, later dominated by fluvial dynamics for much of the Pleistocene and devoid of these aquatic microorganisms. During the Upper Pleistocene and part of the Holocene, the park was flooded during the MIS-1 transgression and a large lagoon was formed and progressively silted up. At this stage, benthic foraminiferal assemblages were dominated by the brackish species Ammonia morphogroup tepida and Haynesina germanica, which were occasionally replaced by marine species (mainly miliolids) during high-energy events. Currently, benthic foraminifera are mainly represented by Ammonia morphogroup tepida in the temporary lagoons and distributary channels, while Ammonia beccarii is dominant in their marginal marine areas. In summary, there is a clear correspondence between the palaeogeographic evolution of the park and its benthic foraminiferal associations, a review of which contributes to increase the knowledge of its remarkable present and past faunal diversity.
- Relationship between substrate, physico-chemical parameters and foraminiferal tests in the Doñana National Park, a Biosphere Reserve in SW SpainPublication . Guerra, Liliana; C. Veiga-Pires, C.; González Regalado, María Luz; Abad, Manuel; Toscano, Antonio; Muñoz, Juan Manuel; Ruiz, Francisco; Rodríguez Vidal, Joaquín; Cáceres, Luis Miguel; Izquierdo, Tatiana; Carretero, María Isabel; Pozo, Manuel; Monge, Guadalupe; Tosquella, Josep; Prudencio, María Isabel; Dias, María Isabel; Marques, Rosa; Gómez, Paula; Romero, VerónicaA multidisciplinar analysis of sediments collected in diferent environments of the Doñana National Park (Guadalquivir estuary, SW Spain) provides an overview of the textural, mineralogical and physico-chemical parameters that control the distribution of benthic foraminiferal tests in this Biosphere Reserve. These microorganisms are absent in the fne quartzitic sands that constitute the substrate of temporary ponds with brief hydroperiods located in the dune systems and spits, as well as in other ponds with low conductivities or hypersaline conditions located in the inner marshlands or near the Guadalquivir river banks. Dead benthic foraminifera are mainly found on phyllosilicate-rich, silty-clayey substrates. The taphonomic analysis of the main species (Ammonia tepida, Haynesina germanica, Trochammina infata, Entzia macrescens) points to its deposit in situ. Cluster analysis permits to delimitate six foraminiferal assemblages. Cluster II (A. tepida+H. germanica) is the dominant assemblage in the central ponds and the margins of the main channels, while cluster IV (T. infata+E. macrescens) is restricted to some ponds located on the high marsh and cluster VI (Ammonia beccarii+Quinqueloculina spp.) is abundant on external beaches. Tidal fuxes cause the transport of these last marine benthic species and some plaktonic forms both to the inner areas of the estuary and to these beaches.