163 research outputs found
Stratigraphic units of the Apulian Tavoliere plain (Southern Italy): Chronology, correlation with marine isotope stages and implications regarding vertical movements
The geologic study of the Apulian Tavoliere plain (Apulia region, southern Italy) is extremely difficult due to the scarcity of outcrops and fauna that could be used for dating. The survey in progress of the 1:50,000 scale geological sheet no. 409 “Zapponeta” (including the coastal zone of the Apulian Tavoliere) has prompted us to tackle this problem by using a large set of borehole data and the AAR dating method applied to ostracod shells, which are capable of colonizing all types of environment as long as there is water. This alternative approach has allowed us to recognise nine stratigraphic units or synthems and, for the first time in this area, to date them, and to find a correlation between them and the cycles of sea level variation. The recognised stratigraphic units are: the Coppa Nevigata sands (NEA; middle Pleistocene: MIS 17–16), argille subappennine unit (ASP; middle Pleistocene: MIS 15–13), the Coppa Nevigata synthem (NVI; middle Pleistocene: MIS 11), the Amendola subsynthem (MLM1; middle Pleistocene: MIS 11), an undifferentiated continental unit (UCI; middle Pleistocene: MIS 8–7), the Foggia synthem (TGF; middle–late Pleistocene: MIS 6), the Carapelle and Cervaro streams synthem (RPL; late Pleistocene: MIS 5–3), and the Inacquata farm synthem (NAQ; Holocene). Within the RPL unit, a buried Cladocora caespitosa bioherm referable to MIS 5.5, lacking in warm fauna, and in which the coral is embedded in clay has been found in some boreholes. This is the first finding of Tyrrhenian deposits with C. caespitosa along the Italian Adriatic coast; the presence of this coral in clayey sediments, a very uncommon occurrence, strengthens the hypothesis that the major fossil reefs grew in coastal waters that were characterised by alluvial inputs of fine sediments, higher turbidity, and higher temperature than today. In addition, on the basis of the current evidence, some consideration about the fauna of the MIS 5.5 layer allows us to hypothesise that the Adriatic Sea underwent a more moderate warming compared to that of the Ionian and Tyrrhenian seas. Instead, the finding in the NVI unit of a tropical lagoonal deposit with stromatolites referred to MIS 11 proves that the warming in this stage was undoubtedly greater than that of MIS 5.5. The MM4 borehole, which goes through the MIS 5 layers of the RPL unit, made it possible to recognise two marine phases during MIS 5: the first is referable to the MIS 5.5–5.3 interval, and the second to MIS 5.1. MIS 5.2 is marked by land emersion, whereas no evidence of land emersion between MIS 5.5 and 5.3 has been found. Also for the first time in this area, uplifting and subsiding areas have been recognised and the vertical movements assessed. In general, the data suggest that the Garganic Apulian foreland and the Amendola highland experienced an uplift, while the central-southern part of the study area, belonging to the Apulian Tavoliere plain, suffered a subsidence with rates increasing from north–northwest to south–southeast. In particular, the finding of the MIS 5.5 buried layer with C. caespitosa has allowed us to fill a gap in the data regarding the recent tectonic movements along the Adriatic coast (Ferranti et al., 2006). This feature proves that there has been a recent subsidence event since MIS 5.5 in the coastal area of the Apulian Tavoliere plain
New objectives and methodologies teaching Geology at the E.T.S.I. Minas de Madrid
El aprendizaje de la Geología requiere, además del conocimiento conceptual
y teórico, de una habilidad que fundamentalmente se consigue con la práctica en
la Naturaleza para entender las formas y estructuras. Así, la enseñanza de la
Geología y disciplinas asociadas, requiere la realización de prácticas en campo.
En el Departamento de Ingeniería Geológica de la E.T.S.I. Minas de Madrid,
apoyándose en las nuevas tecnologías, se han elaborado fichas de salidas al
campo, o “Rutas Geológicas”, acompañadas virtualmente por profesores de la
ETSIMM, en las que se señalan los aspectos geológicos más importantes que se
pueden observar y, en general, del Medio Físico. Estas fichas están disponibles
en la web o se pueden consultar impresas. De esta manera se facilitan
herramientas necesarias para definir entornos virtuales de aprendizaje que se
adapten tanto a la didáctica de cada profesor, como a las necesidades e
inquietudes que les puedan surgir a los alumnos (geología, recursos,
geomorfología, estratigrafía, paleontología, biología, etc) mediante “enlaces”
(aplicaciones móviles, vídeos, fichas en papel). Cualquier profesor puede, de una
manera rápida y sencilla preparar la clase práctica de campo. Asimismo, los
alumnos que lo deseen pueden realizar itinerarios de interés geológico sin
necesidad de ir acompañados de un docente, profundizando en los temas que más
les interesen. En algunos casos también se han rodado vídeos explicativos cortos,
realizados por los propios alumnos como actividad docente, que recogen
aspectos de estos itinerarios. También con este sistema se favorece la realización
de un proyecto interdisciplinar e integrador, ya que estas fichas posibilitan la
integración de información por parte de todos los profesores, y la participación
en la elaboración por parte de los alumnos. La realización de estas fichas ha sido
acogida favorablemente por parte de los alumnos, habiendo incrementado su
motivación y mejorado su rendimiento académico.Learning Geology requires, in addition to the conceptual and theoretical
knowledge, a skill that is primarily achieved with practice in nature to
understand forms and structures. Therefore, the teaching of geology and
associated disciplines, requires carrying out internships in field. In the
Geological Engineering Department of the Madrid School of Mines, we
elaborated "Geological routes," which are virtually accompanied by teachers,
indicating the most important geological aspects that can be observed and, in
general, of the environment. These Geological Routes are available on the web
or you can consult them printed. This provides tools to define virtual learning
processes that are suited to each professor and to the needs and concerns that
may arise to students (geology, resources, geomorphology, stratigraphy,
paleontology, history, biology, etc) through "links" (mobile applications, videos,
cards on paper). Thus, the professor can prepare practical classes on field, in a
quick and easy way. Also, students can make itineraries of geological interest
without having to be accompanied by a professor, deeping into the most
interesting topics. In some cases also explanatory short videos, made by the
students, covering aspects of these itineraries have been filmed. This system
favors the realization of an interdisciplinary project, because these routes enable
the integration of information by professors together with the participation of
students. The realization of these routes has been very welcomed by students,
having increased their motivation accompanied by an improvement in grades
Influence of the substrate bias voltage on the crystallographic structure and surface composition of Ti6A14V thin films deposited by rf magnetron sputtering
In this work, the influence of the substrate bias on the crystalline structure and surface composition of Ti6Al4V thin films prepared by rf magnetron sputtering were studied. Samples were grown onto two different types of substrates: AISI 420 steel and common glass using a Ti6Al4V (99.9 %) target. Substrate bias was varied from -100V to -200 V. Samples were characterized by X-ray diffraction (XRD), Energy Dispersive X-ray Analysis (EDX), Scanning Electron Microscopy (SEM), and X-Ray Photoelectron Spectroscopy (XPS). It was observed that the increase of the substrate voltage improved the crystallinity of the deposited films. The stoichiometry of the deposited thin films was studied by EDX and found to be slightly different from that of the target material. Finally, the passive film spontaneously formed on the deposited films upon exposure to the laboratory atmosphere was studied by XPS. The composition of the passive film is rather complex since it contains several forms of oxidized titanium and vanadium as well as Al2O3.Peer reviewe
Eolianitas costeras del Pleistoceno superior en el "Sitio de Interés Científico de Tufia"(Gran Canarias):sedimentología, petrografía y aminocronología
Los niveles de eolianitas costeras de Tufia (Este de Gran Canaria) aparecen de forma dispersa en un área de 54,1 ha y presentan estratificaciones cruzadas de gran escala, bases erosivas, rizolitos y bandas con gasterópodos terrestres. Estos depósitos eólicos están constituidos por arenas de grano fino y, en menor medida, medio, y están entre bien y moderadamente seleccionadas. Los granos terrígenos predominan sobre los bioclastos en las eolianitas de Aguadulce y Botonera, y en los sedimentos de trasplaya, y tienen proporciones similares en las eolianitas de la Cantera. Entre los granos terrígenos destacan los fragmentos de rocas volcánicas básicas y de minerales ferromagnesianos, mientras que entre los bioclastos predominan las mallas de algas coralinas rojas y moluscos. Las edades definidas mediante análisis de racemización/epimerización de conchas de los géneros Theba y Hemicycla oscilan entre 31,2±6,2 y 39±8,8 Ka BP, por lo que son depósitos eólicos del Pleistoceno Superior, relacionados con las Aminozonas 3 y 4 establecidas para las Islas Canarias orientales y coincidentes con los Episodios de Heinrich 4 y 3. Por lo tanto, las eolianitas de Tufia se habrían formado durante una época de regresión marina y las dataciones corresponderían a la etapa isotópica OIS 3.
Coastal aeolianite strata from Tufia (Eastern Gran Canaria Island) appear dispersed in an area of 54.1 hectares and they show large scale cross bedding, erosive bases, rhizoliths and terrestrial gastropod shells. These aeolian deposits are formed by fine grain sands and, in lower proportion, medium, and are between well and moderately sorted. The terrigenous grains predominate over bioclasts in the aeolianites of Aguadulce and Botonera, and in the backshore sediments, and these components appear in similar proportions at the Cantera. The volcanic basic rocks and ferromagnesian mineral fragments stand out as terrigenous grains, whereas, among bioclasts the red coralline algae and mollusc fragments predominate. The dates defined through racemization/epimerization analysis of Theba and Helicycla shells range between 31,2±6,2 y 39±8,8 Ka BP, that is why they are aeolian deposits of Upper Pleistocene, related to the 3 and 4 Aminozones established for oriental Canary Islands and coincident with 4 and 3 Heinrich Episodes. Therefore, Tufia aeoleanites would have been formed during a marine regression and the date would correspond with the OIS 3 isotopic stage
Organic geochemistry of the Villaviciosa estuary record since 1400 AD (North of Spain)
We have reconstructed the palaeoenvironmental conditions in the Villaviciosa estuary during the last 600 yrs, from the biomarker content (alkanes and alkanoic acids) of the sediment. The amino acid racemization method in ostracodes allowed determining that the sedimentation in the Selorio bay started in 1400 AD. Organic matter was well preserved, although certain microbial activity was interpreted. Three periods were established from the alkane content: 1.- Between 1400 and 1580 AD terrestrial input was dominant; 2.- Between 1580 and 1720 AD there was a major influence of aquatic macrophytes, coinciding with the Little Ice Age, 3.- Between 1720 and 2015 AD there were alternating periods during which land plants or aquatic macrophytes predominated, probably linked to anthropogenic activitiesSe han reconstruido las condiciones paleoambientales de la zona de la ría de Villaviciosa de los últimos 600 años, a partir de los biomarcadores (alcanos y ácidos alcanoicos) presentes en el sedimento. El método de racemización de aminoácidos en ostrácodos ha permitido determinar el inicio de la sedimentación en la ensenada de Selorio, en la ría de Villaviciosa, que comenzó en 1400. La preservación de la materia orgánica es buena, aunque se observa una actividad microbiana importante. A partir de los alcanos se han establecido tres episodios: 1.- Entre 1400 y 1580 predominó el aporte de vegetación terrestre, 2.- Entre 1580 y 1720 hubo una mayor abundancia de macrofitas acuáticas, coincidiendo con la Pequeña Edad del Hielo, 3.- Entre 1720 y 2015, hubo una alternancia de aportes terrestres y de macrofitas acuáticas, posiblemente ligados a la acción antrópic
Organic pollutants (PAHs) derived from the dump of the Thermal Power Station of Aliaga (Teruel)
The aim of this study was to determine if the soils, waters and plants
from the Aliaga dump contained polycyclic aromatic hydrocarbons (PAHs)
and their quantification.The results showed that PAHs concentrations in soils
are in general higher than the reference levels from the Spanish legislation.
Waters and plants contained PAHs but in low concentrations. The possible
actions for remediation (photodegradation and bioremediation) seem to be
unviable here because of the large volume of materials involved, although
its use as an additive for the cement industry and derivatives can be
considered. It is proposed that fluorantene in waters, and phenanthrene and
benzo[ghi]perilene in soils be considered as pollutants as well as to study the
incorporation of PAHs to plantsEl objetivo de este estudio fue determinar y cuantificar los hidrocarburos
policíclicos aromáticos (PAHs) en los suelos, plantas y aguas de la Escombrera
de Aliaga. La concentración de PAHs en las cenizas supera, en general, los
valores establecidos en la legislación española. Las aguas y plantas contienen
PAHs, aunque en concentraciones bajas. La remoción de los materiales para
someterlos a fotodegradación y biorremediación es inviable debido al gran
volumen de la escombrera, aunque se plantea su uso como aditivo en la
fabricación de productos derivados del cemento. Se propone incluir el
fenantreno y benzo[ghi]perileno en el la normativa de suelos, así como el
naftaleno en la de aguas y la elaboración de una legislación sobre la
incorporación de estos compuestos a las planta
Origin and distribution of organochlorine pesticides in present-day sediments of El Hito Lake (Cuenca, Central Spain)
Se llevó a cabo el estudio del estado ambiental actual de la Laguna de
El Hito basado en el análisis y cuantificación de 24 pesticidas
organoclorados (OCPs): hexaclorobenceno, hexaclorociclohexanos,
diclorodifenil-tricloroetano sus homólogos y metabolitos (DDTs), y
ciclodienos (aldrín, dieldrín, endrín, endrín aldehido, endrín cetona, α-
clordano, γ-clordano, endosulfán I, endosulfán II, endosulfán sulfato,
heptacloro, heptacloro epóxido B y metoxicloro). Algunos compuestos
superaron los Niveles Genéricos de Referencia (NGR) para la salud humana
y los ecosistemas del R.D.09/2005. Se determinó su origen a partir de
diversos índices interpretándose tanto aplicaciones históricas como más
recientes. Se obtuvieron los mapas de distribución de los índices y de las
concentraciones de OCPsEnvironmental evaluation of the current state of El Hito Lake referred to
24 organochlorine pesticides (OCPs) was carried out: hexachlorobenzene,
hexachlorocyclohexanes, dichlorodiphenyltrichloroethane their homologs
and metabolites (DDTs), and cyclodienes (aldrin, dieldrin, endrin, endrin
aldehyde, endrin ketone,α-chlordane, γ- chlordane, endosulfan I, endosulfan
II, endosulfan sulphate, heptachlor, heptachlor epóxide B and metoxichlor).
Some of these compounds showed concentrations above the Soil Screening
Levels (SSLs) for human health and ecosystems as is established in
R.D.09/2005. Different indexes were used to determine their origin. Both
historical and recent applications sources were interpreted. Distribution
maps for concentrations and indexes were plotte
Origin and distribution of Rare Earth Elements (REEs) in the water and sediments of El Hito Lake (Cuenca, Central Spain)
Determination of Rare Earth Elements (REEs) in the waters and sediments of El Hito Lake and its drainage basin was carried out. Distribution maps for REEs concentrations show increasing values in the lake sediments from the center to the eastern edge reaching 166.5 mg/kg. In the drainage basin, higher values were observed with a maximum of 350.9 mg/kg in the southern part. Concentrations in the water were considerably lower with a maximum value of 1.3 µg/L. Ce, La and Nd were the most abundant elements. When normalized REE concentrations against NASC (North American Shale Composite), a positive anomaly of Eu in the water and of Nd in the sediments (lake and basin) was observed. The (La/Gd)NASC and (La/Yb)NASC ratios determined the predominance of light REE (LREE) over medium (MREE) and heavy REE (HREE)Se llevó a cabo el estudio de Tierras Raras (REEs) del agua y los sedimentos de la Laguna de El Hito así como de su cuenca de recepción. Los mapas de distribución de las concentraciones de REE en los sedimentos de la laguna mostraron valores crecientes desde el centro hacia el margen este alcanzando 166,5 mg/kg. En la cuenca se midieron valores más elevados llegando hasta 350,9 mg/kg en la mitad sur. Los valores en el agua fueron notablemente inferiores, con un máximo de 1,3 µg/L. El elemento más abundante fue el Ce seguido del Nd. Se normalizaron las concentraciones de REEs frente a las del NASC (North American Shale Composite), observándose una anomalía positiva de Eu en el agua, así como de Nd en los sedimentos (laguna y cuenca).
Mediante los índices (La/Gd)NASC y (La/Yb)NASC se determinó el predominio de las REEs ligeras (LREEs) frente a las medias (MREE) y pesadas (HREE
Organic matter accumulation during the Holocene in the Guadalquivir marshlands (SW Spain)
The distribution of biomarker compounds and magnetic susceptibility observed in the sediment from a 20 m core drilled in the
marshlands of the estuarine region of the Guadalquivir River (southwest coast of Spain) has allowed us to reconstruct the
palaeoenvironmental evolution of this area during the Holocene. Several organic compounds (n-alkanes, ra-ketones, n-alkanols,
n-alkanoic acids and organic sulphur), as well as different biomarker ratios, have been used to show changing environmental
conditions through time. These geochemical proxies suggest good preservation of the organic matter, although some diagenesis
has occurred to particular organic compounds, especially the n-alkanoic acids. Our data indicate a major allochthonous supply of
terrestrial plants, with less influence from aquatic plants or algae through the core. There are markedly different palaeoenvironmental
conditions between the uppermost 5 m (last 6ka cal. B.P.) and the rest of the core. From 5 m (ca 6ka cal. B.P.) to 19 m
(ca 8ka cal. B.P.) depth the palaeoenvironmental conditions were almost constant. Based on organic sulphur content and
n-alkane content logs, anoxic conditions prevailed from 8 to 6ka cal. B.P., while oxic conditions with enhanced convection of
water (prevalence of fluvial input), and consequently a greater organic matter supply, predominated in the upper 5 m of the core.
Similarly, little variation in the magnetic susceptibility profile below 5 m indicates stable environmental conditions, while in the
upper 5 m conditions shifted to one with elevated water input and clastic sediment supply. This is linked to palaeofloral
alterations in the Guadiamar/Guadalquivir drainage basins and/or anthropogenic effects. We propose that from ca 8 to 6 ka cal.
B.P. a stable landscape physiognomy in the surroundings of the estuarine area of the Guadalquivir River, with a predominance of
pines and grassland. However, over the last 6ka cal. B.P. a variation in the terrestrial plant biomarker compounds suggests an
alternation of relatively dry and humid phases and/or the impact of human populations on altering the vegetation community
have occurred
Biometría de Strombus bubonius Lamark 1791 del yacimiento de Cerro Largo (Roquetas de Mar, Almería)
This paper deals with a comparative metrical study of the mesogastropods Strombus bubonius and Strombus
latus. The former from the raised marine deposits of Cerro Largo (Roquetas de Mar, Almería) of Middle
Pleistocene age, and the second still living in the Gulf of Guinea and Cabo Verde Islands. The high correlation
between length and maximum width reveals a positive allometrical relationship in fossil and living species.
There is a good metrical coincidence between Cerro Largo S. bubonius representatives and S. latus from
Cabo Verde, while S. latus representatives from Guinea and Senegal reach larger sizes. It is postulated that
a partially developed sexual dimorphism explains the co-occurrence at the same beds of small and big
sized S. bubonius shells
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