Evolución geológica cuaternaria del valle del río Deba (Gipuzkoa)

196 p.

El paisaje vegetal durante la prehistoria reciente en la vertiente mediterránea de Euskal Herria

421 p. (Bibliogr.: 375-421

Caracterización de los depósitos fluviales del río Ebro en la cuenca de Miranda de Ebro (Burgos)

[ES] La evolución fluvial del río Ebro ha sido analizada de forma desigual, siendo más numerosas las investigaciones centradas en su curso medio y bajo. En este trabajo se describe el sistema de terrazas fluviales elaborado por el río Ebro a su paso por la Cuenca de Miranda de Ebro (Álava – Burgos). Se han reconocido cinco niveles de terrazas (T1-T5) mediante su análisis estratigráfico, morfológico y sedimentológico. Las terrazas se sitúan a unas alturas que oscilan entre los 68 y los 5 m sobre el nivel actual del río Ebro. El relleno sedimentario de los niveles más elevados (T1-T4) está compuesto por gravas poligénicas bien clasificadas y muy redondeadas con presencia puntual de niveles de arenas; mientras que el nivel más bajo (T5) está constituido enteramente por partículas finas. Los resultados apuntan hacia variaciones de caudal y aportes sedimentarios, en relación con las oscilaciones climáticas cuaternarias, como los factores que gobiernan la evolución fluvial en la Cuenca de Miranda de Ebro, en coherencia con los modelos de evolución propuestos para otros puntos de la cuenca hidrográfica

Geology alive. GeoBizirik.org

Geology is the science that studies the Earth, its composition, structure and origin in addition to past and present phenomena that leave their mark on rocks. So why does society need geologists? Some of the main reasons are listed below: - Geologists compile and interpret information about the earth’s surface and subsoil, which allows us to establish the planet’s past history, any foreseeable changes and its relationship with the rest of the solar system. - Society needs natural resources (metals, non-metals, water and fossil fuels) to survive. The work of geologists is therefore a key part of finding new deposits and establishing a guide for exploring and managing resources in an environmentally-friendly way. - The creation of geological maps allows us to identify potential risk areas and survey different land uses; in other words, they make an essential contribution to land planning and proposing sustainable development strategies in a region. - Learning about Geology and the proper use of geological information contributes to saving lives and reducing financial loss caused by natural catastrophes such as earthquakes, tsunamis, volcanic eruptions, flooding and landslides, while also helping to develop construction projects, public works, etc. Through the proposed activities we aim to explain some of the basic elements of the different specialities within the field of Geological Sciences. In order to do this, four sessions have been organised that will allow for a quick insight into the fields of Palaeontology, Mineralogy, Petrology and Tectonics.

Geology alive. GeoBizirik.org

Geology is the science that studies the Earth, its composition, structure and origin in addition to past and present phenomena that leave their mark on rocks. So why does society need geologists? Some of the main reasons are listed below: - Geologists compile and interpret information about the earth’s surface and subsoil, which allows us to establish the planet’s past history, any foreseeable changes and its relationship with the rest of the solar system. - Society needs natural resources (metals, non-metals, water and fossil fuels) to survive. The work of geologists is therefore a key part of finding new deposits and establishing a guide for exploring and managing resources in an environmentally-friendly way. - The creation of geological maps allows us to identify potential risk areas and survey different land uses; in other words, they make an essential contribution to land planning and proposing sustainable development strategies in a region. - Learning about Geology and the proper use of geological information contributes to saving lives and reducing financial loss caused by natural catastrophes such as earthquakes, tsunamis, volcanic eruptions, flooding and landslides, while also helping to develop construction projects, public works, etc. Through the proposed activities we aim to explain some of the basic elements of the different specialities within the field of Geological Sciences. In order to do this, four sessions have been organised that will allow for a quick insight into the fields of Palaeontology, Mineralogy, Petrology and Tectonics.

Palaeoenvironmental analysis based on alluvial ostracod assemblages of the Cenicero section (lower Miocene, NW Ebro Basin)

In this work we perform for the first time a palaeoenvironmental and biostratigraphic analysis of the lower Miocene alluvial deposits of the Cenicero section (NW sector of the Ebro Basin; N Iberian Peninsula), based on the ostracod and micromammal assemblages. One of the main characteristics of this section is the unusual abundance on non-reworked ostracods present in the studied samples compared to other European sequences of similar age and sedimentary environment. This fact has allowed us to develop precise palaeoenvironmental reconstructions. The variations of the identified ostracod assemblages, defined by species such as Cyclocypris laevis, Ilyocypris bradyi, Ilyocypris gibba, Limnocythere sp. or Pseudocandona parallela, record the development of small, ephemeral and shallow ponds in a distal alluvial and/or floodplain environment. Towards the upper part of the section the ponds appear to be less ephemeral, being the aquatic systems more stable for ostracods development. Variations in the water temperature and salinity have been observed along the section, which are related to changes in the local pluviometric regime. On the other hand, the presence of micromammals in one of the studied samples has allowed the precise dating of this section. Thus, the presence of Armantomys daamsi dates the Cenicero section as Agenian (lower Miocene), local zone Y2 (MN2).