Person:
Muñoz García, María Belén

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First Name
María Belén
Last Name
Muñoz García
Affiliation
Universidad Complutense de Madrid
Faculty / Institute
Ciencias Geológicas
Department
Geodinámica, Estratigrafía y Paleontología
Area
Estratigrafía
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UCM identifierORCIDScopus Author IDDialnet IDGoogle Scholar ID

Search Results

Now showing 1 - 9 of 9
  • Publication
    Land surface temperature changes in Northern Iberia since 4000 yr BP, based on δ13C of speleothems
    (Elsevier, 2011) Martín Chivelet, Javier; Muñoz García, María Belén; Edwards, R. Lawrence; Turrero Jiménez, María Jesús; Ortega Martínez, Ana Isabel
    The surface temperature changes for the last 4000 years in northern inland Iberia (an area particularly sensitive to climate change) are determined by a high resolution study of carbon stable isotope records of stalagmites from three caves (Kaite, Cueva del Cobre, and Cueva Mayor) separated several tens of kilometers away in N Spain. Despite the local conditions of each cave, the isotopic series show a good overall coherence, and resulted to be strongly sensitive to surface temperature changes. The record reflects alternating warmer and colder intervals, always within a temperature range of 1.6 °C. The timing and duration of the intervals were provided by 43 230Th–234U (ICP-MS) ages. Main climatic recognized periods are: (1) 3950–3000 yr BP: warm period punctuated by cool events around ~3950, 3550 and 3250 yr BP; (2) 2850–2500 yr BP cold interval (Iron Age Cold Period); (3) 2500–1650 yr BP moderate warm period (Roman Warm Period), with maximum temperatures between 2150 and 1750 yr BP; (4) 1650– 1350 yr BP cold interval (Dark Ages Cold Period), with a thermal minimum at ~1500 yr BP; (5) 1350– 750 yr BP warm period (Medieval Warm Period) punctuated by two cooler events at ~1250 and ~850 yr BP; (6) 750–100 yr BP cold period (Little Ice Age) with extremes occurring at 600–500 yr BP, 350–300 yr BP, and 150–100 yr BP; and (7) the last 150 years, characterized by rapid but no linear warming (Modern Warming). Remarkably, the presented records allow direct comparison of recent warming with former warm intervals such as the Roman or the Medieval periods. That comparison reveals the 20th century as the time with highest surface temperatures of the last 4000 years for the studied area. Spectral analysis of the time series shows consistent climatic cycles of ~400, ~900 and ~1300 yr, comparable with those recognized in the North Atlantic marine record, the Greenland ice cores, and other terrestrial records for the middle–late Holocene, suggesting common climate forcing mechanisms related to changes in solar irradiance and North Atlantic circulation patterns.
  • Publication
    Speleothem architectural analysis: integrated approach for stalagmite-based paleoclimate research
    (Elsevier, 2017-05) Martín Chivelet, Javier; Muñoz García, María Belén; Cruz, Juncal A.; Ortega Martínez, Ana Isabel; Turrero Jiménez, María Jesús
    Carbonate stalagmites have become increasingly attractive to Quaternary paleoclimate research, as they can be accurately dated by radiometric methods and concurrently yield high-resolution multi-proxy records of past climate conditions. Reliable series however require the precise characterization of stalagmite internal icrostratigraphy,4 a task too often poorly accomplished despite the recent advances in speleothem research. This weakness is due to the lack of a robust integrative methodological framework capable of integrating the wide range of petrographical and micro-stratigrafical methods currently used in speleothem characterization. For covering this need, this review introduces the Speleothem Architectural Analysis (SAA), a holistic approach inspired in well-established stratigraphic procedures such as the architectural element analysis and the sequence stratigraphy, commonly used by geoscientists for categorizing internal stratigraphic heterogeneities in sedimentary deposits. The new approach establishes a six-fold hierarchy of speleothem architectural elements and their bounding surfaces: individual crystallites (1st order), single growth layers (2nd order), speleothem fabrics (3rd order), stacking patterns sets (4th order), morphostratigraphic units (5th order), unconformity-bounded units and major unconformities (6th order). Each category of architectural element is formed in a different range of time, from intervals as short as a year/season to others of centuries or millennia. The SAA, which has the capability of incorporating any petrographic or stratigraphic classification, provides a useful, systematic, and versatile tool for unraveling the complexities of speleothem growth, and thus for genetically interpreting stalagmites in a multi-temporal scale. A detailed speleothem stratigraphy must be the basis for performing robust reconstruction of paleoclimate series. They should precede and accompany any work focused in absolute age dating or in reconstructing paleoclimate by means of any geochemical proxy
  • Publication
    The Blake geomagnetic excursion recorded in a radiometrically dated speleothem
    (Elsevier Science B.V., Amsterdam, 2012) Osete López, María Luisa; Martín Chivelet, Javier; Rossi, Carlos; Edwards, R. Lawrence; Egli, Ramon; Muñoz García, María Belén; Wang, Xianfeng; Pavón Carrasco, Francisco Javier; Heller, Friedrich
    One of the most important developments in geomagnetism has been the recognition of polarity excursions of the Earth’s magnetic field. Accurate timing of the excursions is a key point for under standing the geodynamo process and for magnetostratigraphic correlation. One of the best-known excursions is the Blake geomagnetic episode, which occurred during marine isotope stage MIS 5, but its morphology and age remain controversial. Here wes how, for the first time, the Blake excursion recorded in a stalagmite which was dated using the uranium-series dis equilibrium techniques. The characteristic remanent magnetisation is carried by fine-grained magnetite. The eventis documented by two reversed intervals (B1 and B2). The age of the eventis estimated to be between 116.5 ± 0.7 kyr BP and 112.0 ± 1.9 kyr BP, slightly younger (~3–4 kyr) than recent estimations from sedimentary records sated by astronomical tuning. Low values of relative palaeointensity during the Blake episode are estimated, but a relative maximum in the palaeofield in tensity coeval with the complete reversal during the B2 interval was observed. Duration of the Blake geomagnetic excursion is 4.5 kyr, two times lower than single excursions and slightly higher than the stimated diffusion time for the inner core (~3 kyr).
  • Publication
    Geodivulgar: Geología y Sociedad
    (2017-06-29) García Frank, Alejandra; Canales Fernández, María Luisa; Muñoz García, María Belén; Rodríguez García, Sergio; Martínez Gutierrez, Gemma; Sarmiento, Graciela N.; Cózar Maldonado, Pedro; Gómez Heras, Miguel; Díaz Megias, Isabel; Rico Arjona, Rocio; Alonso Recio, Carlos; Salazar Ramirez, Roselis Waikiria; Berrocal Casero, Melani; Rodríguez García de Castro, Isabel; Borrego Salgado, David; Sánchez Fontela, Noelia; Martín Perea, David Manuel; Montesinos del Valle, Mercedes; Fesharaki, Omid; Iglesias Álvarez, Nuria; Navalpotro Gordo, Tania; Portales Níñez, Killian; Armendáriz Sanz, Andrés; Rey Samper, Jesús Javier; Del Moral González, Begoña; Gonzalo Parra, Lorena; Coronado Vila, Ismael; Pérez Martín del Campo, Daniel; Hontecillas Tamayo, Daniel; Calonge García, María Amelia; Taboada Trujols, Irene; Rodrigo Sanz, Ana; Moreno De Alborán Calvo, Fernando; Poves Garrido, Consuelo; Hernández Fragua, Laura; Silva, Silvia
  • Publication
    Comparison of speleothem fabrics and microstratigraphic stacking patterns in calcite stalagmites as indicators of paleoenvironmental change
    (Elsevier, 2016) Muñoz García, María Belén; Cruz, J.; Martín Chivelet, Javier; Ortega, Ana Isabel; Turrero, M.J.; López Elorza, M.
    In the necessary task of obtaining high-resolution paleoclimate series from speleothems, the characterization of their internal microstratigraphy is a useful tool for: a) improving geochronology, and b) reaching a more complete knowledge of the speleothem formation and evolution through time and thus obtaining additional paleoenvironmental information. However, the development of standardized methodologies for microstratigraphic characterization is a pending task. In this paper, two different approaches allow construction of microstratigraphic logs for three stalagmites retrieved from two different caves. The logs correspond to vertical variations in speleothem fabrics and in microstratigraphic stacking patterns. The “fabrics logs” essentially provide information about the drip rate (sometimes used as a precipitation proxy) and the regularity or irregularity of each drip in the short-term. The “microstratigraphic stacking patterns logs” can be interpreted to obtain information about the changes in drip rates in the mid- and long-term. The results show a broad correlation between both kinds of logs that supports their validity as paleoenvironmental proxies. Fabrics formed under relatively constant and regular drips (columnar compact, open and elongated) usually constitute aggradational or progradational microstratigraphic stacking patterns. On the other hand, retractional stacking patterns are usually related with fabrics precipitated under more irregular drips (dendritic and columnar microcrystalline).However, this relation is not rigid and the information obtained from the logs is not equivalent, but complementary. The combination of both logs allows reconstruction of the hydrological history for each drip site. As all the obtained information derives directly from the drip conditions, drip effects result to be very important and can, in some cases, overwhelm the paleoclimate information recorded in each stalagmite.
  • Publication
    Sedimentary facies and three-dimensional reconstructions of upper Oligocene meander belts from the Loranca Basin, Spain
    (The American Association of Petroleum Geologists, 2010-02) Díaz Molina, Margarita; Muñoz García, María Belén
    In this article, we reconstruct and explore the three-dimensional (3-D) architecture of superimposed meander-belt sediments as an analog of subsurface reservoirs. Two exposures, named the Huete anticline and Garcinarro, were selected from the Loranca Basin, central Spain. In both of them, deposits are dominated by meandering river sediments of Oligocene age. Some point bars show fining-upward sequences of sedimentary structures and grain size typical of the helicoidal flow, but most of them present multiple vertical changes in grain size and are characterized by the occurrence of small-scale cross-stratification filling scours. The origin of these structures is related to oppositely rotating spiral vortices associated with flow separation along the convex bank of the meander bends. The 3-D architecture of superimposed meander-belt sediments allowed the reconstruction of meandering channel orientations and meander wavelength, calculation of the net/gross sandstone content, and the fraction of interconnected sandstone bodies. The 3-D architecture revealed that the interconnection areas are nearly absent when the orientations of the superimposed meander belts were perpendicular and that interconnection areas are more abundant and larger where a coincidence in the orientations of superimposed meander belts is observed. Horizontal projections of the highly interconnected areas allow calculation of the area fraction where one or more sandstone bodies could be intersected by vertical drilling. Differences in sandstone fraction between the two studied exposures were caused by the proximity to the Altomira Sierra thrust belt, which forms the western margin of the Loranca Basin.
  • Publication
    GEODIVULGAR: Geología y Sociedad
    (2018-06-29) García Frank, Alejandra; Canales Fernández, Mª Luisa; Muñoz García, María Belén; González Acebrón, Laura; Rodríguez García, Sergio; Martínez Gutiérrez, Gemma; Cózar Maldonado, Pedro; Calonge García, María Amelia; Gómez Heras, Miguel; Henriques, Maria Helena; Díaz Mejías, Isabel; Alonso Recio, Carlos; Rico Arjona, Rocío; Salazar Ramirez, Roselis Waikiria; Hontecillas Tamayo, Daniel; Berrocal Casero, Melani; Martín Perea, David Manuel; Rodríguez García de Castro, Isabel; Sánchez Fontela, Noelia; Martín Millán, Mariano; Seijas Morales, Naomi; Conde Carrión, Teresa; Domínguez Valdés, Elena; Sierra Ramírez, Nuria; Durán León, Alfonso; Ortiz Lucena, Antonio; Luceño Martín, Elena; Herranz García, Sergio; Fesharaki, Omid; Iglesias Álvarez, Núria; Navalpotro Gordo, Tania; Portales Núñez, Killian; Borrego Salgado, David; Montesinos del Valle, Mercedes; Poves Garrido, Consuelo; Hernández Fragua, Laura; Coronado Vila, Ismael; Armendáriz Sanz, Andrés; Rey Samper, Jesús Javier; Taboada Trujols, Irene; Guilló Carrasco, Vicente Eduardo; González Blázquez, Javier; Peña Vilanova, Jorge; Sarmiento, Graciela N.; Silva, Silvia; Rodrigo Sanz, Ana; del Moral González, Begoña; Gonzalo Parra, Lorena; Pérez Martín del Campo, Daniel; Chicote Alvira, Gabriel
  • Publication
    Estudios paleoclimáticos y paleoambientales en cuevas kársticas
    (2011) Martín Chivelet, Javier; Muñoz García, María Belén; Garralón, A.; Gómez, P.; Turrero, M.J.; Ortega, A.I.; Edwards, R.L.; Cheng, H.; Santisteban, J.I.; Mediavilla, R.; Pérez-Monserrat, Elena M.; Charco Romero, María
  • Publication
    Land surface temperature changes in Northern Iberia since 4000 yr BP, based on δ13C of speleothems
    (Elsevier, 2011-02-22) Martín Chivelet, Javier; Muñoz García, María Belén; Edwards, R. Lawrence; Turrero, María J.; Ortega, Ana I.
    The surface temperature changes for the last 4000 years in northern inland Iberia (an area particularly sensitive to climate change) are determined by a high resolution study of carbon stable isotope records of stalagmites from three caves (Kaite, Cueva del Cobre, and Cueva Mayor) separated several tens of kilometers away in N Spain. Despite the local conditions of each cave, the isotopic series show a good overall coherence, and resulted to be strongly sensitive to surface temperature changes. The record reflects alternating warmer and colder intervals, always within a temperature range of 1.6 °C. The timing and duration of the intervals were provided by 43 230Th–234U (ICP-MS) ages. Main climatic recognized periods are: (1) 3950–3000 yr BP: warm period punctuated by cool events around ~3950, 3550 and 3250 yr BP; (2) 2850–2500 yr BP cold interval (Iron Age Cold Period); (3) 2500–1650 yr BP moderate warm period (Roman Warm Period), with maximum temperatures between 2150 and 1750 yr BP; (4) 1650– 1350 yr BP cold interval (Dark Ages Cold Period), with a thermal minimum at ~1500 yr BP; (5) 1350– 750 yr BP warm period (Medieval Warm Period) punctuated by two cooler events at ~1250 and ~850 yr BP; (6) 750–100 yr BP cold period (Little Ice Age) with extremes occurring at 600–500 yr BP, 350–300 yr BP, and 150–100 yr BP; and (7) the last 150 years, characterized by rapid but no linear warming (Modern Warming). Remarkably, the presented records allow direct comparison of recent warming with former warm intervals such as the Roman or the Medieval periods. That comparison reveals the 20th century as the time with highest surface temperatures of the last 4000 years for the studied area. Spectral analysis of the time series shows consistent climatic cycles of ~400, ~900 and ~1300 yr, comparable with those recognized in the North Atlantic marine record, the Greenland ice cores, and other terrestrial records for the middle–late Holocene, suggesting common climate forcing mechanisms related to changes in solar irradiance and North Atlantic circulation patterns.