Estudios Geologicos-Madrid最新文献

{"title":"Las asociaciones de microfauna como indicadores de cambios paleoambientales en los ciclos fluvio-lacustres Miocenos (NE de la Cuenca del Duero, España)","authors":"A. Herrero-Hernández, G. Alonso-Gavilán, J. Llovera","doi":"10.3989/EGEOL.42381.400","DOIUrl":"https://doi.org/10.3989/EGEOL.42381.400","url":null,"abstract":"The siliclastic and carbonate deposits are interbedded in the Villadiego area (Miocene, NE Duero Basin). They have been subdivided into two high-rank depositional sequences: DDS and CDS. The sedimentary analysis of these units and the study of the microfauna content, mainly ostracods, led to the identification of lacustrine-fluvial interaction systems. The sedimentary characteristics reveal the existence of fluvial systems of gravel, flood plains and lacustrine systems that were interconnected and intimately related in north-south direction. In the sedimentological analysis, thirteen types of fluvial and lacustrine lithofacies and six genetic facies associations were recognized. The top of DDS is the result of lake level risings. The CDS shows a deepening-shallowing cycle. The ostracod micropaleontological analysis of the sediments have been studied, with the aim of reconstructing the palaeoenvironmental evolution of this area. These microfauna assemblages integrated with the analysis of the sedimentary facies allowed to conclude the existence of lakes with a water-bearing level of few tens of meters. A change in the chemical conditions of the waters, which evolved from oligohaline and carbonated to mesohaline and sulphated is concluded.","PeriodicalId":50496,"journal":{"name":"Estudios Geologicos-Madrid","volume":"43 1","pages":"053"},"PeriodicalIF":0.7,"publicationDate":"2016-11-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78898190","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Fossil Suidae (Artiodactyla, Mammalia) from Aves Cave I and nearby sites in Bolt’s Farm Palaeokarst System, South Africa","authors":"M. Pickford, D. Gommery","doi":"10.3989/EGEOL.42389.404","DOIUrl":"https://doi.org/10.3989/EGEOL.42389.404","url":null,"abstract":"Excavations carried out since 2011 at Bolt’s Farm Palaeokarst System, South Africa, have led to the recovery of interesting remains of suids, notably from Aves Cave I. The taxa present are Potamochoeroides hypsodon and Notochoerus capensis , the same as those that occur at Makapansgat. The new Notochoerus material, which includes an upper third molar and a lower fourth premolar, strengthens the conclusion that this genus is a suine and not a tetraconodont as thought for the past half century. Potamochoeroides has thickened mandibular rami indicating that it descended from the genus Dasychoerus that dispersed into Africa from Eurasia about 5 million years ago. Other karst deposits at Bolt’s Farm have yielded a younger suid fauna comprising Metridiochoerus andrewsi and Phacochoerus modestus , indicating that the Bolt’s Farm Karst System was active for a considerable period of time (ca 4.5 Ma - 1.8 Ma). The fact that all the suid taxa from Bolt’s Farm are hypsodont indicates that the palaeoenvironment contained abundant grass.","PeriodicalId":50496,"journal":{"name":"Estudios Geologicos-Madrid","volume":"37 1","pages":"059"},"PeriodicalIF":0.7,"publicationDate":"2016-11-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74450962","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Resolución de enigmas geológicos e históricos utilizando técnicas gemológicas avanzadas: Caso del ópalo noble de Franco Dávila (1772)","authors":"Javier Garcia-Guinea, J. González-Alcalde, M. Furió, A. Jorge, F. Garrido","doi":"10.3989/EGEOL.42459.410","DOIUrl":"https://doi.org/10.3989/EGEOL.42459.410","url":null,"abstract":"The large precious opal weighting 33 grams fitted in a silver jewel and exposed to visitors at the Museo Nacional de Ciencias Naturales (MNCN) is well documented in: (i) its own mounting (1772), (ii) at the 775 document of the Archive of the MNCN and (iii) the 395 specimen described in the of Pedro Franco Davila catalogue. The X-ray diffractogram (XRD) performed onto the opal block is very similar to other opals of volcanic origin containing varied amounts of cristobalite, tridymite and amorphous silica. The Raman spectrum shows a band peaked at 242, 343 and 416 cm -1 associated with O-Si-O stretching groups; other spectral band peaked at 780 and 819 cm -1 corresponding to vibration of symmetrical O-Si-O rings of 3 and 4 link members, plus other minor bands. The Raman spectrum is also very similar to those observed in Mexican opals of volcanic origin containing an spectral band of stretching nodes v1 (OH) at 3233, 3393, 3511, 3628 cm -1 related to OH groups with hydrogen bonds of isolated silanol groups. The interferometric confocal dual microscope 3D (MCI3D), which is a nondestructive facility of high resolution and LED technology reveals the geometry of graver tools on the silver jewel and the computed tomography X-ray highlights the opal cutting as a squared princess type and silver chloride infillings of a crack probably caused by a shock on a corner. Under the scanning electron microscope we observed barite, sealed veins of silica rich in Mn and opal with high contents of Al and K which, along with the historical data, the piece can be attributed to the historical site of opals hosted in Slovakia andesite rocks, this data explains the optical light behavior in the cabochon. The silver jewel has large amounts of Hg and AgCl indicating amalgam method. In addition the natural AgS 2 phases probably come from Nueva Espana (year 1772) in full production of silver in such time. The association of new analytical non-destructive techniques combines the preservation of samples together with significant analytical data allowing us to deduce genetic mineral processes, provenances and manufacturing techniques of materials. These facilities allow the characterization, interpretation, conservation and enhancement of cultural and archaeological heritage.","PeriodicalId":50496,"journal":{"name":"Estudios Geologicos-Madrid","volume":"2 1","pages":"056"},"PeriodicalIF":0.7,"publicationDate":"2016-11-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84690066","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Heterogeneidad lateral en las muestras de roedores del tramo T1 del Mioceno Medio de Somosaguas (Pozuelo de Alarcón, Madrid)","authors":"F. Blanco, M. H. Fernández","doi":"10.3989/EGEOL.42255.386","DOIUrl":"https://doi.org/10.3989/EGEOL.42255.386","url":null,"abstract":"Rodent associations are habitually used in palaeoenviromental inferences. Assuming lateral homogeneity in fossil content within stratigraphic levels, sometimes these inferences are performed using the relative abundances of species included in such associations. Nevertheless, this homogeneity has never been checked empirically in species proportions inside the same fossiliferous level. Because of that, in this work we compared two samples from T1 level of the Somosaguas fossil site (middle Miocene), which were separated laterally by 30 m. Although both samples show identical faunal composition from a qualitative viewpoint, analysis realized through Monte Carlo randomizations indicated the existence of significant differences in relative abundances of different species between the two samples. These results could be due to 1) different sedimentary behaviour of dental pieces from different species due to differences in size; 2) small size of sediment samples combined with high density of fossil remains in level T1 of Somosaguas; 3) differential time averaging related to presence of successive alluvial fans, associated to population changes due to environmental changes during the Aragonian. Our results show the need of cautiousness when palaeoenviromental inferences are based on relative abundances of micromammalian species.","PeriodicalId":50496,"journal":{"name":"Estudios Geologicos-Madrid","volume":"45 1","pages":"052"},"PeriodicalIF":0.7,"publicationDate":"2016-11-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84097156","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Estimación de la escorrentía superficial para el cálculo de la recarga a los acuíferos del macizo kárstico de los Ports de Beseit (Tarragona, España) combinando balance de agua en el suelo y análisis de hidrogramas de caudales","authors":"S. Martínez, E. Custodio","doi":"10.3989/EGEOL.42132.374","DOIUrl":"https://doi.org/10.3989/EGEOL.42132.374","url":null,"abstract":"For the right estimation of aquifer recharge by precipitation surface taking into account runoff is particularly relevant. Non considering it in the estimation of the groundwater resources can overestimate them. In the Baix Ebre aquifer system, in southern Catalonia, the surface and vadose zone runoff produced in the karstified carbonate formations in the Ports de Beseit massif has to be evaluated in order to achieve a better estimation of the resources transferred from this massif to the Plana de La Galera plain. Starting from the conceptual hydrogeological model, the average annual runoff is estimated. It includes the discharge from temporal perched aquifers in the Ports de Beseit massif, in the Matarrana river basin, and in the SE watershed to the Plana de La Galera plain. This is performed by analyzing the river and tributaries hydrographs, the filling and emptying hydrographs of the Ulldecona reservoir, and the soil water balance using the Visual Balan code applied to obtain the runoff in the Ulldecona reservoir watershed. The runoff has been estimated about 105±20 mm·yr −1 , which represents 20–30% of average annual recharge in the Ports, estimated with soil water balance and atmospheric chloride deposition balance, about 350–500 mm·yr −1 , which is mostly transferred laterally to the Plana de La Galera plain.","PeriodicalId":50496,"journal":{"name":"Estudios Geologicos-Madrid","volume":"1 1","pages":"045"},"PeriodicalIF":0.7,"publicationDate":"2016-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90895440","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Petrophysical characterization of the Dolomitic Member of the Boñar Formation (Upper Cretaceous; Duero Basin, Spain) as a potential CO 2 reservoir","authors":"A. Suarez-Gonzalez, T. Kovács, A. Herrero-Hernández, F. Gómez‐Fernández","doi":"10.3989/EGEOL.42191.384","DOIUrl":"https://doi.org/10.3989/EGEOL.42191.384","url":null,"abstract":"La Formacion Bonar (Cretacico Superior) es una sucesion carbonatica que aflora al Norte de la Cuenca del Duero (Espana). Segun datos previos, el Miembro Dolomitico de esta formacion es el que muestra caracteristicas petrograficas mas favorables para almacenamiento geologico de CO 2 . \u0000El principal objetivo de este trabajo es el aporte de elementos de juicio que apoyen, clarifiquen y concreten –a un nivel de estudio preliminar– la potencialidad del Miembro Dolomitico de la Formacion Bonar como roca almacen. \u0000La Formacion Bonar (Cretacico Superior) es una sucesion carbonatica que aflora al Norte de la Cuenca del Duero (Espana). Segun datos previos, el Miembro Dolomitico de esta formacion es el que muestra caracteristicas petrograficas mas favorables para almacenamiento geologico de CO 2 . \u0000El principal objetivo de este trabajo es el aporte de elementos de juicio que apoyen, clarifiquen y concreten –a un nivel de estudio preliminar– la potencialidad del Miembro Dolomitico de la Formacion Bonar como roca almacen.","PeriodicalId":50496,"journal":{"name":"Estudios Geologicos-Madrid","volume":"22 1","pages":"048"},"PeriodicalIF":0.7,"publicationDate":"2016-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81738071","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Hidrogeología del Karst de Pico Frentes (Cordillera Ibérica, España)","authors":"P. Rosas, E. Sanz, I. Menéndez-Pidal","doi":"10.3989/EGEOL.42132.375","DOIUrl":"https://doi.org/10.3989/EGEOL.42132.375","url":null,"abstract":"The karst system of Pico Frentes has developed within an Upper Cretaceous calcareous series whose well-defined folded geometry determines that its aquifer reserves are held mainly in three hydraulically-connected synclines, with a groundwater capacity of between 5 and 7 hm 3 . The recharge to this unconfined peneplain aquifer is autogenous and diffuse. On a large scale, groundwater flow is directed by the base of the synclines, while on a small scale, it flows along groundwater conduits towards the Fuentetoba Spring (210 l/s) and source of the River Mazos (50 l/s), following a highly variable flow regime of low inertia, with other smaller discharges emanating during periods of high water. Analysis of hydrographs of these springs indicates a very variable rate system and little power regulating natural, characteristic of a typical karstic aquifer, with great capacity for renewal and low residence time. \u0000Using hydrogram simulations of these upwellings using a mathematical rainfall-runoff model, a detailed quantification of the average water balance was made for a twenty-year time series. This water balance consists of 16,86 hm 3 rainfall (100%); natural recharge, 8,35 hm 3 (49,53%); EVT 8,50 hm 3 (50,41%); pumped groundwater abstractions, 0,01hm 3 (0,06%); surface runoff, 0 hm 3 , groundwater transfers to other aquifer, 0 hm 3 .","PeriodicalId":50496,"journal":{"name":"Estudios Geologicos-Madrid","volume":"52 1","pages":"047"},"PeriodicalIF":0.7,"publicationDate":"2016-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79860891","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Late Palaeozoic to Triassic formations unconformably deposited over the Ronda peridotites (Betic Cordilleras): Evidence for their Variscan time of crustal emplacement","authors":"C. Galdeano, M. D. R. Cruz","doi":"10.3989/EGEOL.42046.368","DOIUrl":"https://doi.org/10.3989/EGEOL.42046.368","url":null,"abstract":"The age of the emplacement of the Ronda Peridotites has been widely debated during recent decades, and ages ranging from the Palaeozoic to the early Miocene have been proposed, although most of the current interpretations suggest an Oligocene-Miocene age. In this article, we describe two meta-sedimentary formations (the lower one formed by detrital sediments and the upper one by marbles) that were unconformably deposited over the Ronda peridotites and now record low-grade metamorphism. The detrital formation contains layers of acidic rocks with an age of 269±9 Ma and the overlying marbles are assumed to be Triassic. The existence of these unconformable formations over the peridotites is crucial for the dating of the exhumation of the latter. The presence of peridotite clasts in the detrital formation indicates that peridotites were exposed during the Permian and other data suggest that peridotites were exhumed during the late Carboniferous. During the Alpine cycle, the peridotites operated as an element situated at the bottom of the tectonically higher Alpujarride/Sebtide unit (the Jubrique unit) and forming part of it, then being incorporated to the Alpine thrusts of this unit.","PeriodicalId":50496,"journal":{"name":"Estudios Geologicos-Madrid","volume":"32 1","pages":"043"},"PeriodicalIF":0.7,"publicationDate":"2016-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83174198","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Cartographie des linéaments géologiques en domaine aride par extraction semi-automatique à partir d’images satellitaires: Exemple à la région d’El Kseïbat (Sahara algérien)","authors":"N. Hammad, M. Djidel, N. Maabedi","doi":"10.3989/EGEOL.42158.377","DOIUrl":"https://doi.org/10.3989/EGEOL.42158.377","url":null,"abstract":"Geologists in charge of a detailed lineament mapping in arid and desert area, face the extent of the land and the abundance of eolian deposits. This study presents a semi-automatic approach of extraction of lineament, different from other methods, such as the automatic extraction and manual extraction, by being both fast and objective. It consists of a series of digital processing (textural and spatial filtering, binarization by thresholding and mathematic morphology ... etc.) applied to a Landsat 7 ETM+scene. This semi-automatic approach has produced a detailed map of lineaments, while taking account of tectonic directions recognized in the region. It helps mitigate the effect of dune deposits meet the specifications of arid environment. The visual validation of these linear structures, by geoscientists and field data, allowed the identification of the majority of structural lineaments or at least those tried geological.","PeriodicalId":50496,"journal":{"name":"Estudios Geologicos-Madrid","volume":"22 1","pages":"049"},"PeriodicalIF":0.7,"publicationDate":"2016-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91320800","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Nuevas evidencias acerca de la presencia de Stegomastodon platensis Ameghino, 1888, Proboscidea: Gomphotheriidae, en el Pleistoceno tardío de Chile central","authors":"R. Labarca, M. T. Alberdi, J. L. Prado, P. Mansilla, F. A. Mourgues","doi":"10.3989/EGEOL.42199.385","DOIUrl":"https://doi.org/10.3989/EGEOL.42199.385","url":null,"abstract":"This paper contextualizes, describes and taxonomically assigned cranial and dental Gomphotheriidae materials from the El Trebal 1, late Pleistocene form central Chile. Starting from metric and morphological variables fossils are included in Stegomastodon platensisStegomastodon platensis. Taxonomic implications of this finding as well as some regional paleoenvironmental history are discussed.","PeriodicalId":50496,"journal":{"name":"Estudios Geologicos-Madrid","volume":"15 1","pages":"046"},"PeriodicalIF":0.7,"publicationDate":"2016-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74766849","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}