Estudios Geologicos-Madrid最新文献

{"title":"Structure of the Alpujarride Complex and hydrogeological observations to the NW of Sierra Tejeda (Granada and Malaga provinces, Betic Internal Zone, Spain)","authors":"C. Galdeano, J. Prieto-Mera, B. Andreo","doi":"10.3989/EGEOL.43395.509","DOIUrl":"https://doi.org/10.3989/EGEOL.43395.509","url":null,"abstract":"espanolAl NO de Sierra Tejeda solo se pueden diferenciar dos unidades tectonicas alpujarrides, la de Almijara y, sobre ella, la de Robledal, simplificando divisiones previas. Datos hidrogeologicos avalan esta interpretacion ya que apuntan a la posible conexion hidraulica entre dos areas ocupadas por marmoles (sectores de Tejeda y Rodaderos) que previamente han sido consideradas como unidades tectonicas diferentes lo que lo hace improbable. En la unidad Robledal la presencia de gneises en la parte inferior de la secuencia litologica permite su correlacion con otras unidades del grupo Guajares-Jubrique/ Los Reales (grupo superior de unidades del Complejo Alpujarride). Deformaciones extensionales se superponen al cabalgamiento de unidades, pero a las que no damos la enorme importancia atribuida en previos modelos, pues no permiten, al menos en esta area, la diferenciacion de nuevas unidades tectonicas. Se muestran, ademas, nuevas fallas E-O situadas al N de Sierra Tejeda, que facilitaron el desplazamiento hacia el oeste de la Zona Interna Betica. EnglishIn the NW of Sierra Tejeda (Spain) it is possible differentiate only two Alpujarride tectonic units, i.e. the Almijara and, in an upper position, the Robledal unit, simplifying previous divisions. Hydrogeological data support this interpretation since a hydraulic connection exists between the two areas occupied by marbles (Sierra Tejeda and Rodaderos sectors). Both areas has been previously considered as belonging to two different tectonic units not directly connected. In the Robledal unit, gneisses in the lower part of the lithologic sequence correlate with other units of the Guajares-Jubrique/Los Reales group (upper group of Alpujarride units). Extensional deformations are superposed over these tectonic units, but, according to field observations, they have not the enormous importance attributed to them in previous models, as they do not differentiate new tectonic units, at least in this area. New E-W faults are drawn along the northern edge of Sierra Tejeda, contributing to the westward drift of the Betic Internal Zone.","PeriodicalId":50496,"journal":{"name":"Estudios Geologicos-Madrid","volume":"34 1","pages":"90"},"PeriodicalIF":0.7,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72921325","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":"Structuration profonde dans la région de Bir M’Chergua (Nord-Est de la Tunisie). Implications hydrogéologiques","authors":"A. Ferjani, R. Guellala, A. Amiri, Amira Merzougui, M. H. Inoubli","doi":"10.3989/EGEOL.42955.461","DOIUrl":"https://doi.org/10.3989/EGEOL.42955.461","url":null,"abstract":"The Bir M’Chergua region, located fifty kilometers from the capital Tunis, is an important economic pole in Tunisia. However, the water shortage resulting from many successive drought periods has led to a significant degradation of the various industrial, tourist and agricultural activities in this region. Groundwater exploitation can alleviate this situation, but it requires a better characterization of aquifers. In this context, the present study aims to provide precisions on the Bir M’Chergua hydrogeological scheme by determining the subsurface structures from gravimetric data interpretation. \u0000Residual anomaly, vertical derivative and total horizontal gradient maps are calculated from the Bouguer anomaly to identify and delimit the causative sources. The Euler deconvolution technique is also applied to estimate these sources depth. \u0000The structural map resulting from gravimetric interpretation highlights buried structures and discontinuities of different direction and depth that can greatly influence the Bir M’Chergua aquifer system geometry and functioning. In fact, the highlighting of tectonic features at more than 1500 m depth around the Jebel Oust dome explains the origin and the high salinity of the thermal waters in this sector; such tectonic accidents have favored a deep penetration of the recharge water as well as their contact with the Triassic terrains.","PeriodicalId":50496,"journal":{"name":"Estudios Geologicos-Madrid","volume":"139 1","pages":"075"},"PeriodicalIF":0.7,"publicationDate":"2018-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86567978","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":"Procedencia del material pétreo de los molinos de los yacimientos Cogotas I (Bronce Medio y Tardío) de la Cuenca del Duero y modelos consecuentes de flujo","authors":"M. López-Plaza, Á. E. Arroyo, I. G. Gómez, F. J. López-Moro","doi":"10.3989/EGEOL.42955.462","DOIUrl":"https://doi.org/10.3989/EGEOL.42955.462","url":null,"abstract":"The source provenance of twelve hand grindstones of Cogotian sites from the sedimentary Duero Basin was characterized using petrographic, mineralogical and geochemical criteria, according to an operational process previously proposed. Many of the provenances were determined after trace-element normalized diagrams and comparative diagrams with respect to available data from potential source areas. This methodology confirms that the geochemical signature can be seen as an archaeological fingerprint which allows the identification of facies or rock sub-types from the established source areas. Granite sources are the commonest provenance, although granodiorite, orthogneisses and sandstone are also involved, all of them belonging to the Variscan Basement. One of these source areas includes copper minerals, which could have been used for metallurgical purposes. Probably, since the early phase of Cogotas I, the principle of least effort no longer was a guiding force to boost the supply of material. The archaeological sites experienced a long-distance raw material supply in crossed directions, according to the established sources areas, indicating a dense network of connections between the commnunities of the region at a hecto-kilometric scale.","PeriodicalId":50496,"journal":{"name":"Estudios Geologicos-Madrid","volume":"100 1","pages":"074"},"PeriodicalIF":0.7,"publicationDate":"2018-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88540658","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":"Nueva especie de ostrácodo del Plioceno de la Depresión del Guadalquivir (S.O. de España)","authors":"F. Ruiz, M. L. González-Regalado, M. Abad","doi":"10.3989/EGEOL.43012.468","DOIUrl":"https://doi.org/10.3989/EGEOL.43012.468","url":null,"abstract":"A new ostracod species from Pliocene sediments of the Gualdalquivir Basin (SW Spain), Cyprideis civis nov. sp., is herein described and illustrated. This new species is distinguished in having small size (length: Cyprideis civis nov. sp. inhabited in the bottom, sandy sediments of an infralittoral palaeoenvironment, subjected to occasional freshwater fluxes and storms. In this scenario, this species was part of the gastropod diet, as evidenced by the bioerosion traces found in the valves.","PeriodicalId":50496,"journal":{"name":"Estudios Geologicos-Madrid","volume":"417 1","pages":"073"},"PeriodicalIF":0.7,"publicationDate":"2018-02-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78106989","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":"El registro sedimentario de la Cuenca del Bajo Segura (SE España) a través del análisis de correspondencia: implicaciones paleoambientales","authors":"Hugo Corbí","doi":"10.3989/EGEOL.42908.459","DOIUrl":"https://doi.org/10.3989/EGEOL.42908.459","url":null,"abstract":"The Messinian and Pliocene record of the Bajo Segura Basin has been analysed by multivariate detendred correspondence analysis (DCA). The obtained results enables a comprehensive and synthetic examination of the sedimentary record, considering the distribution of benthic and planktic foraminifera (ecological groups) recorded in six representative sections of the basin, three on the northern sector (Colmenar, Torrellano and Elche) and three on the southern part (Garruchal, La Pedrera and El Canal). From the statistical analysis, contrasted with the bibliographical sources available, it can be concluded that: a) the southern sector presents, in comparison with the northern sector, a greater diversity of marine environments; and b) the three analysed synthems have their own characteristics in terms of variety and representation of their registered sedimentary environments.","PeriodicalId":50496,"journal":{"name":"Estudios Geologicos-Madrid","volume":"1 1","pages":"071"},"PeriodicalIF":0.7,"publicationDate":"2017-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72550068","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":"Las formaciones yesíferas del Triásico Superior y Jurásico Inferior de Camarasa, en el frente Surpirenaico Catalán","authors":"Josep Maria Salvany","doi":"10.3989/EGEOL.42914.460","DOIUrl":"https://doi.org/10.3989/EGEOL.42914.460","url":null,"abstract":"The present study describes the lithostratigraphic characteristics of the Canelles Gypsum Formation (lower Keuper) and the Lecera Gypsum Formation (Lower Jurassic) in the area of Camarasa, in the Catalan South Pyrenean front. The Lecera Formation forms a cyclic alternation of gypsum and carbonate layers of about 300 m thick. Gypsum displays gray laminated, white laminated, and white massive lithofacies. Carbonate forms minor layers of dolobreccia and thin bedded dolomicrite lithofacies. On the contrary, the Canelles Formation forms a 100 m thick massive sequence mainly composed of white and brown laminated gypsum, with carbonate layers restricted to the base of the formation and to its middle part. On the base, the carbonate layers consist of laminated dolomicrite lithofacies, while in the middle part they display laminated dolomarl, thin bedded dolomicrite and oolitic lithofacies, which are arranged in four carbonatic cycles of few meters thick. Both formations originated in similar evaporitic environments of very stable sulfate lagoons fed by sea water and away from the influence of detrital inputs. In such lagoons sedimentation mainly consisted of laminated gypsum with minor carbonate beds, representing sediments of relatively high and low concentration of the lagoon water respectively, but without precipitation of more soluble salts (halite).","PeriodicalId":50496,"journal":{"name":"Estudios Geologicos-Madrid","volume":"153 1","pages":"070"},"PeriodicalIF":0.7,"publicationDate":"2017-11-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77526176","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":"Correlación entre parámetros químicos, cristalográficos y espectroscópicos en la termometría de grafito aplicada a una aureola de contacto del monzogranito de La Soledad (Andes venezolanos)","authors":"K. Reátegui, Manuel Martínez","doi":"10.3989/EGEOL.42748.444","DOIUrl":"https://doi.org/10.3989/EGEOL.42748.444","url":null,"abstract":"Graphite samples from a metamorphic contact aureole between phyllites of the Cerro Azul Association (Palaeozoic) and La Soledad Monzogranite, in the Venezuelan Andes, were studied by chemical (% inorganic carbon and isotopic distribution), crystallographic (DRX) and spectroscopic (Raman) techniques in order to assess changes in the graphite in the vicinity of the contact, the correlation between the different parameters, and the determination of the higher temperature reached by the host rock during igneous intrusion. The δ13C reached less negative values near the monzogranite, caused by devolatilization; the graphite present just in contact with the pluton experienced retrograde recrystallization, which causes a shift towards more negative values. The calculated degree of graphitization intervals (GD = 53–80) corresponds to a well-structured mineral with ordered packaging. The peak metamorphic temperature at the contact was calculated from crystallographic (XRD) and spectroscopic (Raman) parameters with great agreement in both techniques, registering the 528 ± 16 and 526 ± 20 oC respectively. The metapelitic rocks reached the Cordierite Zone (cordierite + biotite + muscovite) in the contact aureole where the graphite is well ordered and in hexagonal microtexture. Factors such as fluid activity and the subsequent retrograde recrystallization have an effect on isotopic redistributions after the intrusive event, as well as on the crystallinity change rate with the temperature, avoiding a clear correlation between the isotopic variations of 13C in graphite and the temperature.","PeriodicalId":50496,"journal":{"name":"Estudios Geologicos-Madrid","volume":"33 1","pages":"069"},"PeriodicalIF":0.7,"publicationDate":"2017-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86344909","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":"Pistas fósiles y dubiofósiles del Ediacárico y Cámbrico del Anticlinal de Alcudia, España","authors":"J. Simón","doi":"10.3989/EGEOL.42724.442","DOIUrl":"https://doi.org/10.3989/EGEOL.42724.442","url":null,"abstract":"The fossil record of the Ediacaran—Cambrian transition in Spain provides potentially useful information to understand this critical episode in the history of life on Earth. In the present work, new findings of trace fossils and dubiofossils are described from the upper Ediacaran and lowermost Cambrian of the Alcudian unit in the Alcudia Anticline, at the southern margin of the Central Iberian Zone (valle de Alcudia, Iberian Massif, Spain). Two new trace fossil sites are described from the Upper Alcudian subunit and assigned to the Fortunian stage (lower Cambrian, Terreneuvian series) and to the regional Lower Corduban substage. They contain examples of arthropod-like scratches ( Monomorphichnus lineatus ), small bilobed trails (similar to Archaeonassa ), an inclined burrow with spreite (may be a teichichnid), and long unbranched burrows with very fine transversal structure (probably the ventral surface of Psammichnites ). Torrowangea aff. rosei and possible body fossils of late Ediacaran age are described from the Lower Alcudian subunit, including a disc resembling a frond holdfast and a diamond-shaped complex structure with no known equivalents.","PeriodicalId":50496,"journal":{"name":"Estudios Geologicos-Madrid","volume":"10 1","pages":"068"},"PeriodicalIF":0.7,"publicationDate":"2017-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78117765","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":"Primer registro de Nopachtus coagmentatus (Xenarthra, Glyptodontidae) para la Provincia de Catamarca, Argentina. Revisión del género Nopachtus","authors":"Martín Zamorano, G. Moreno, N. E. Vaccari, C. M. Falcón, A. M. Combina, R. Bonini","doi":"10.3989/EGEOL.42809.449","DOIUrl":"https://doi.org/10.3989/EGEOL.42809.449","url":null,"abstract":"Nopachtus coagmentatus was recognized by Ameghino in 1888. Holotype comes from Brochero Formation (Montehermosan - Chapadmalalan [early Pliocene - late Pliocene]), near to Villa Cura Brochero (Cordoba). First find of this species for the Catamarca Province is reported. Remains found are described, its provenance detailed and the corresponding stratigraphic log is presented. The mentioned material, came from Salicas Formation, cropping out in the paraje Suri Yaco, consists of 14 osteoderms of the dorsal region of the carapace attributed to N. coagmentatus , 12 complete and 2 fragmented corresponding to the media and posterodorsal region of the carapace. These osteoderms present a central figure surrounded by two row of peripheral figures, and figures that would correspond to a third row, always incomplete. The first row has between 10 and 12 figures and the second between 19 and 22; the figures are pentagonal or, mainly, hexagonal. In turn, all specimens known today for this genus, that included two species, is revised. Until this communication, only two reliable records, and several doubtful were recognized for N. coagmentatus ; while for N. cabrerai Zamorano, Scillato-Yane, Gonzalez Ruiz & Zurita only the holotype was given to known.","PeriodicalId":50496,"journal":{"name":"Estudios Geologicos-Madrid","volume":"1 1","pages":"067"},"PeriodicalIF":0.7,"publicationDate":"2017-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76102038","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":"La identificación del uso de fuentes secundarias de materiales líticos asistida por SIG: El Arroyo Chasicó (Argentina) como caso de estudio","authors":"Luciana Catella, G. Barrientos, F. Oliva","doi":"10.3989/EGEOL.42720.441","DOIUrl":"https://doi.org/10.3989/EGEOL.42720.441","url":null,"abstract":"The aim of this paper is to present the methodology deployed in the Chasico basin (southern Pampas, Argentina) in order to discuss the differential contribution of primary and secondary lithic sources in the spatial and technological organization of late Holocene hunter-gatherers societies. Such methodology is based on the comparative analysis of curves constructed with data obtained from virtual transects traced over continuous spatial models representing different properties of regional lithic landscapes. Those models were created by interpolation using a technique called Inverse Distance Weighted (IDW) from scattered information recovered at point locations ( i.e. archaeological sites and localities; n = 12). Investigated raw materials were rhyolites and two varieties of quartzites, and the monitored variables were relative frequency (F%), relative weight (P%) and cortex index (IC). Our results suggest that both varieties of quartzites were mainly procured from secondary sources distributed along the basin and that rhyolites were mostly obtained from primary sources located at the headwaters.","PeriodicalId":50496,"journal":{"name":"Estudios Geologicos-Madrid","volume":"1 1","pages":"066"},"PeriodicalIF":0.7,"publicationDate":"2017-07-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89136510","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}