Papers by José López-gómez
Geotemas ( Madrid ), 2004
Geotemas ( Madrid ), 2001
The Aptian El Burgal Mb. up to 85 m in thickness crops out in the SE Iberian Ranges (Central Spai... more The Aptian El Burgal Mb. up to 85 m in thickness crops out in the SE Iberian Ranges (Central Spain). It is m ainly comprised o f fine to coarse-grained' , white and ochre sandstones (arkoses) with intercalated levels o f medium-sized, rounded quartzite pebbles, fine red sediments and local coal (lignite) horizons. Detailed study o f isopachs, 15 logs and 6 facies associations indicate that the El Burgal Mb. was deposited within different environments o f sandy fluvial systems and fluvialwave-tidal interaction environments, com m only truncated by tidal channels from northern to southern zones respectively. The fluvial environments are represented by bedload, deposited as bars that till channels o f m ainly low but also o f high sinuosity. Crevasse splays are frequent, showing long complex sheet-sandstone bodies interspersed with the channel fill in the northern area. The fluvio-m arine transitional zone is located in the central area, where sandy fluvial meandering deposits cut soil horizons and coal seams in flood plain areas. Fluvial-wave-tide interaction deltas vertically alternate with shallow water marine sediments o f Urgonian carbonate facies in the southern zone. Dispersion o f the sediments are clearly controlled by the NW-SE tectonic alignment o f Lower Cretaceous rift development that represented the Iberian Basin, with an interaction o f both extrabasinal and intrabasinal tectonics resulting in a regression w ithin a long term transgressive episode.
The species rubra sp. nov., a new triadotypomorphan insect from the Iberian Ranges, is described ... more The species rubra sp. nov., a new triadotypomorphan insect from the Iberian Ranges, is described on the basis of a newly discovered specimen, found in fine grained sandstones of alluvial origin, in the lowermost part of the Eslida Formation (Buntsandstein facies), in the central part of the Iberian Ranges. The occurrence of a triadotypomorphan suggests an Anisian age of the Eslida Formation. The species represents the oldest Mesozoic insect described from Spain, and provides interesting information to better appreciate the process of ecosystems recovery after the Permian-Triassic boundary crisis.
Journal of Iberian Geology, Oct 30, 2009
The species rubra sp. nov., a new triadotypomorphan insect from the Iberian Ranges, is described ... more The species rubra sp. nov., a new triadotypomorphan insect from the Iberian Ranges, is described on the basis of a newly discovered specimen, found in fine grained sandstones of alluvial origin, in the lowermost part of the Eslida Formation (Buntsandstein facies), in the central part of the Iberian Ranges. The occurrence of a triadotypomorphan suggests an Anisian age of the Eslida Formation. The species represents the oldest Mesozoic insect described from Spain, and provides interesting information to better appreciate the process of ecosystems recovery after the Permian-Triassic boundary crisis.
Journal of Sedimentary Research, May 13, 2013
Aluminum-phosphate-sulfate (APS) minerals, formed during early diagenesis in relation to acid met... more Aluminum-phosphate-sulfate (APS) minerals, formed during early diagenesis in relation to acid meteoric waters, are the main host of Sr and S in the Early-Middle Triassic continental sandstones of the Iberian Ranges (east of the Iberian Peninsula). The sources of these elements and the effects of paleoenvironmetal changes on these sources and on the formation of APS minerals during Early-Middle Triassic times, were established on the basis of Sr and S isotopic analyses. The S and Sr data (d 34 S V-CDT = +11 to +14% and 87 Sr/ 86 Sr = 0.7099-0.7247, respectively) can be interpreted as resulting from mixing of different sources. Strontium was sourced from the dissolution of pre-existing minerals like K-feldspar and clay minerals inherited from the source areas, causing high radiogenic values. However, the isotopic signal must also be influenced by other sources, such as marine or volcanic aerosol that decreased the total 87 Sr/ 86 Sr ratios. Marine and volcanic aerosols were also sources of sulfur, but the d 34 S was lowered by dissolution of pre-existing sulfides, mainly pyrite. Pyrite dissolution and volcanic aerosols would also trigger the acid conditions required for the precipitation of APS minerals. APS minerals in the study area are found mainly in the Cañizar Formation (Olenekian?-Aegian), which has the lowest 87 Sr/ 86 Sr ratios. The lower abundance of APS minerals in the Eslida Formation (Aegian-Pelsonian) may indicate change in the acidity of pore water towards more alkaline conditions, while the increased 87 Sr/ 86 Sr ratios imply decreased Sr input from volcanic activity and/or marine aerosol inputs during Anisian times. Therefore, the decrease in abundance of APS minerals from the Early to Middle Triassic and the variations in the sources of Sr and S are indicative of changes in paleoenvironmental conditions during the beginning of the Triassic Period. These changes from acid to more alkaline conditions are also coincident with the first appearance of carbonate paleosols, trace fossils, and plant fossils in the upper part of the Cañizar Formation (and more in the overlying Eslida Formation) and mark the beginning of biotic recovery in this area. The presence of APS minerals in other European basins of the Western Tethys (such as the German Basin, the Paris Basin and the southeastern France and Sardinia basins) could thus also indicate that unfavorable environmental conditions caused delay in biotic recovery in those areas. In general, the presence of APS minerals may be used as an indicator of arid, acidic conditions unfavorable to biotic colonization.
Geotemas ( Madrid ), 2001
Macla: revista de la Sociedad Española de Mineralogía, Jul 1, 2017
Journal of the Geological Society, May 17, 2018
Sedimentary Geology, Apr 1, 2011
This article appeared in a journal published by Elsevier. The attached copy is furnished to the a... more This article appeared in a journal published by Elsevier. The attached copy is furnished to the author for internal non-commercial research and education use, including for instruction at the authors institution and sharing with colleagues. Other uses, including reproduction and distribution, or selling or licensing copies, or posting to personal, institutional or third party websites are prohibited. In most cases authors are permitted to post their version of the article (e.g. in Word or Tex form) to their personal website or institutional repository. Authors requiring further information regarding Elsevier's archiving and manuscript policies are encouraged to visit: https://www.elsevier.com/copyright Author's personal copy Earthquake-induced soft-sediment deformation structures in Upper Jurassic open-marine microbialites (Neuquén Basin, Argentina
Palaeogeography, Palaeoclimatology, Palaeoecology, Nov 1, 2014
Global and Planetary Change, 2017
Palaeogeography, Palaeoclimatology, Palaeoecology, Oct 1, 2023
Estudios Geologicos-madrid, Oct 30, 1986
Review of Palaeobotany and Palynology, Dec 1, 2009
Plant fossils are rarely preserved within the Upper Permian of western Europe as the majority of ... more Plant fossils are rarely preserved within the Upper Permian of western Europe as the majority of continental deposits consists of siliciclastic redbeds. Because organic matter such as plant debris and palynomorphs is destroyed by oxidizing conditions, these red sedimentary facies were often considered as "devoid of life". This paper presents new palaeobotanical data from the Upper Permian strata of Minorca (Balearic Islands, Spain). In addition, a rich and diverse "Thuringian" palynoflora was recovered from the Permian sediments, and several megafloral taxa are recorded. Additionally, a detailed sedimentological analysis of the studied section is provided. The Permian succession shows a general evolution from a ponded floodplain environment to sand-sheet rivers flowing across a semi-arid alluvial plain. Additionally, new palaeobotanical elements, added to the study of palaeosols, allow reconstruction of Late Permian plant growth within the terrestrial environment, as well as a palaeoenvironment reconstruction of the preserved sedimentary interval. At the transition between ponds and alluvial plain deposits, root systems surprisingly similar to those known in extant mangroves are described for the first time within Permian deposits. As there are no other palaeobotanical remains preserved in association, the type of plant that inhabited this environment remains conjectural.
Palaeogeography, Palaeoclimatology, Palaeoecology, Dec 1, 2005
Actas de las XXXII Jornadas de la Sociedad Española de Paleontología, 2016, ISBN 978-84-9138-016-0, págs. 471-478, Sep 21, 2016
En este trabajo se presenta una recopilación de las especies de ammonoideos conocidas en los mate... more En este trabajo se presenta una recopilación de las especies de ammonoideos conocidas en los materiales de facies Muschelkalk del Triásico Medio de las diferentes cuencas españolas,
El objetivo del presente trabajo es la prospección de recursos hídricos subterráneos en el extrem... more El objetivo del presente trabajo es la prospección de recursos hídricos subterráneos en el extremo sureste del territorio saharaui, para paliar las necesidades básicas de la población nómada de la región, y a la vez evaluar la posibilidad de creación de nuevos asentamientos en el área. El trabajo es el primero de carácter geológico, estratigráfico, geofísico e hidrogeológico que se lleva a cabo en la zona. Mediante los trabajos de geofísica se ha podido detectar que en algunos lugares los valores de resistividad eléctrica aparente disminuyen hasta profundidades superiores a los 50 metros, abriendo una puerta a la posibilidad de encontrar agua en cantidad suficiente especialmente en zonas de fracturas profundas. Los lugares preferentes para emplazar captaciones son los abanicos aluviales, las sabkhas y fondos de valle sometidos a fracturación. Queda por delante un amplio campo de investigación cuando se den las condiciones políticas estables que permitan una investigación con mayor d...
The Triassic of the Iberian Peninsula presents three carbonate epeiric platforms (Lower Muschelka... more The Triassic of the Iberian Peninsula presents three carbonate epeiric platforms (Lower Muschelkalk, Upper Muschelkalk and Imon Fm.). These three carbonate platforms are intensively dolomitized with a lower part made up of grey dolomites and an upper part of white dolomites. The white dolomites are sabkha-type dolomites and the grey dolomites reflux-type dolomites. The petrography stable isotopes and Sr isotopes of the grey and white dolomites suggest a late recrystallization process related to deep burial or hydrothermal conditions during the Jurassic-Cretaceous rifting.
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Papers by José López-gómez