Las rocas hipoabisales hercinianas y tardi-hercinianas del sector centro-oriental del sinclinal de Llavorsí (Pirineo Central)

Los materiales silúricos, devónicos que constituyen el sinclinal de Llavorsí (Pirineo central) están atravesados por dos grupos principales de rocas ígneas hipoabisales. El primer grupo esta formado por rocas de composición básica e intermedis afectadas por un metamorfismo herciniano de grado muy bajo y forman parte, por tanto, de un episodio magmático básico anterior a las deformaciones principales hercinianas. Las transformaciones secundarias sufridas por estas rocas impiden deducir, apartir del estudio de loss elementos mayores, su pertenencia a una serie ignea determinada si bien pueden distinguirse claramente dos asociaciones con distintas relaciones Mg/Fe. El segundo grupo, claramente postectónico, está constituido únicamente por rocas ácidas (felsitas y pórfidos graníticos y granodioriticos), relacionadas aparentemente con el plutonismo calcoalcalino tardi-herciniano

Las rocas hipoabisales hercinianas y tardi-hercinianas del sector centro-oriental del sinclinal de Llavorsí (Pirineo Central)

Los materiales silúricos, devónicos que constituyen el sinclinal de Llavorsí (Pirineo central) están atravesados por dos grupos principales de rocas ígneas hipoabisales. El primer grupo esta formado por rocas de composición básica e intermedis afectadas por un metamorfismo herciniano de grado muy bajo y forman parte, por tanto, de un episodio magmático básico anterior a las deformaciones principales hercinianas. Las transformaciones secundarias sufridas por estas rocas impiden deducir, apartir del estudio de loss elementos mayores, su pertenencia a una serie ignea determinada si bien pueden distinguirse claramente dos asociaciones con distintas relaciones Mg/Fe. El segundo grupo, claramente postectónico, está constituido únicamente por rocas ácidas (felsitas y pórfidos graníticos y granodioriticos), relacionadas aparentemente con el plutonismo calcoalcalino tardi-herciniano

Las rocas hipoabisales hercinianas y tardi-hercinianas del sector centro-oriental del sinclinal de Llavorsí (Pirineo Central)

Los materiales silricos, devnicos que constituyen el sinclinal de Llavors (Pirineo central) estn atravesados por dos grupos principales de rocas gneas hipoabisales. El primer grupo esta formado por rocas de composicin bsica e intermedis afectadas por un metamorfismo herciniano de grado muy bajo y forman parte, por tanto, de un episodio magmtico bsico anterior a las deformaciones principales hercinianas. Las transformaciones secundarias sufridas por estas rocas impiden deducir, apartir del estudio de 10s elementos mayores, su pertenencia a una serie ignea determinada si bien pueden distinguirse claramente dos asociaciones con distintas relaciones Mg/Fe. El segundo grupo, claramente postectnico, est constituido nicamente por rocas cidas (felsitas y prfidos granticos y granodioriticos), relacionadas aparentemente con el plutonismo calcoalcalino tardi-herciniano

Cuantificación del crecimiento de pliegues con sedimentos sintectónicos asociados: aplicación al anticlinal de Santarén (orógeno cubano, cuenca de antepaís de las Bahamas)

The Santaren anticline, located offshore, is the outermost structure of the Cuban fold and thrust belt. The detailed study of the geometry of the syntectonic sediments associated with this anticline has allowed us to document its kinematic evolution. A number of reverse modelling geometrical techniques have been used to quantify fold gr owth (crestal structural relief, shortening, limb dip, interlimb angle and axial plane dip) during different stages. The values obtained for each of these parameters have been plotted versus time in order to s h ow their evolution through time. The conclusions achieved from all these plots are consistent and enable us to understand how fold amplification took place. Thus, the data obtained indicate that fold gr owth initiated during Middle Eocene, or before, and it continued until present day. Fold amplification took place at extremately slow rates from Middle Miocene to present day, and perhaps faster during deposition of older growth strata. In particular, data concerning rotation of the southern limb and interlimb angle tightening support this hypothesis. The data presented in this paper regarding the Santaren anticline evolution disagree with previous plate tectonic models that postulate the end of tectonic activity in this region during Middle Eocene

Cuantificación del crecimiento de pliegues con sedimentos sintectónicos asociados: aplicación al anticlinal de Santarén (orógeno cubano, cuenca de antepaís de las Bahamas)

El estudio detallado de la geometría de los sedimentos sintectónicos asociados al crecimiento del anticlinal de Santaren, localizado bajo el mar en la parte más externa de la faja plegada cubana, ha permitido documentar la evolución cinemática de dicho pliegue. Para ello se han utilizado una serie de técnicas geométricas de modelización inversa que permiten cuantificar el crecimiento del pliegue en función de: el relieve estructural de la cresta, el acortamiento, el buzamiento de los flancos, el ángulo entre flancos y el buzamiento del plano axial para diferentes estadios durante el depósito de los sedimentos sintectónicos. Para cada uno de los parámetros, los valores obtenidos se representan en una gráfica con respecto a la edad correspondiente, y de esta manera se conoce su evolución a través del tiempo. Las conclusiones que se obtienen a partir de las diferentes gr á ficas son coherentes entre sí y permiten vislumbrar datos importantes de la evolución del pliegue. Así, los resultados obtenidos indican que el anticlinal se inició en el Eoceno Medio, o anteriormente, y su crecimiento perduró hasta la actualidad. El anticlinal creció de forma extremadamente lenta a partir del Mioceno Medio y tal vez lo hizo de forma mas rápida durante el depósito de los sedimentos sintectónicos más antiguos. En particular, los datos sobre la rotación del flanco sur del anticlinal y sobre la variación del ángulo entre flancos parecen estar de acuerdo con esta última hipótesis. Estos nuevos datos sobre la evolución del anticlinal de Santaren contradicen modelos previos que postulan que la deformación en esta región culminó en el Eoceno Medio.The Santaren anticline, located offshore, is the outermost structure of the Cuban fold and thrust belt. The detailed study of the geometry of the syntectonic sediments associated with this anticline has allowed us to document its kinematic evolution. A number of reverse modelling geometrical techniques have been used to quantify fold gr owth (crestal structural relief, shortening, limb dip, interlimb angle and axial plane dip) during different stages. The values obtained for each of these parameters have been plotted versus time in order to s h ow their evolution through time. The conclusions achieved from all these plots are consistent and enable us to understand how fold amplification took place. Thus, the data obtained indicate that fold gr owth initiated during Middle Eocene, or before, and it continued until present day. Fold amplification took place at extremately slow rates from Middle Miocene to present day, and perhaps faster during deposition of older growth strata. In particular, data concerning rotation of the southern limb and interlimb angle tightening support this hypothesis. The data presented in this paper regarding the Santaren anticline evolution disagree with previous plate tectonic models that postulate the end of tectonic activity in this region during Middle Eocene

Horizontal Wavenumber Spectra of Vertical Vorticity and Horizontal Divergence of Mesoscale Dynamics in the Mesosphere and Lower Thermosphere Using Multistatic Specular Meteor Radar Observations

Specular meteor radars (SMRs) have significantly contributed to the understanding of wind dynamics in the mesosphere and lower thermosphere (MLT). We present a method to estimate horizontal correlations of vertical vorticity (Qzz) and horizontal divergence (P) in the MLT, using line-of-sight multistatic SMRs velocities, that consists of three steps. First, we estimate 2D, zonal, and meridional correlation functions of wind fluctuations (with periods less than 4 hr and vertical wavelengths smaller than 4 km) using the wind field correlation function inversion (WCFI) technique. Then, the WCFI's statistical estimates are converted into longitudinal and transverse components. The conversion relation is obtained by considering the rotation about the vertical direction of two velocity vectors, from an east-north-up system to a meteor-pair-dependent cylindrical system. Finally, following a procedure previously applied in the upper troposphere and lower stratosphere to airborne wind measurements, the longitudinal and transverse spatial correlations are fitted, from which Qzz, P, and their spectra are directly estimated. The method is applied to a special Spread spectrum Interferometric Multistatic meteor radar Observing Network data set, obtained over northern Germany for seven days in November 2018. The results show that in a quasi-axisymmetric scenario, P was more than five times larger than Qzz for the horizontal wavelengths range given by ∼50–400 km, indicating a predominance of internal gravity waves over vortical modes of motion as a possible explanation for the MLT mesoscale dynamics during this campaign

Extreme Horizontal Wind Perturbations in the Mesosphere and Lower Thermosphere Over South America Associated With the 2022 Hunga Eruption

On 15 January 2022, the Hunga volcano produced a massive explosion that generated perturbations in the entire atmosphere. Nonetheless, signatures in the mesosphere and lower thermosphere (MLT) have been challenging to identify. We report MLT horizontal wind perturbations using three multistatic specular meteor radars on the west side of South America (spanning more than 3,000 km). The most notorious signal is an exceptional solitary wave with a large vertical wavelength observed around 18 UT at all three sites, with an amplitude of ∼50 m/s mainly in the westward direction. Using a customized analysis, the wave is characterized as traveling at ∼200 m/s, with a period of ∼2 hr and a horizontal wavelength of ∼1,440 km in the longitudinal direction, away from the source. The perturbation is consistent with an L1 Lamb wave mode. The signal's timing coincides with the arrival time of the tsunami triggered by the eruption

On the formation of gold nanoparticles from [AuIIICl4]- and a non-classical reduced polyoxomolybdate as an electron source: A quantum mechanical modelling and experimental study

Polyoxometalate (POM)-mediated reduction and nucleation mechanisms in nanoparticle (NP) syntheses are still largely unknown. We carried out comprehensive theoretical analysis using density functional theory (DFT) to gain insight into the molecular and electronic changes that occur during the reduction of HAuIIICl4 with the Kabanos-type polyoxomolybdate, Na{(MoV2O4)3(µ2-O)3(µ2-SO3)3(µ6-SO3)}2]15-. In the system presented herein the electrons are supplied by the POM, making the computational thermodynamic analysis more feasible. Our results reveal that this particular POM is a multi-electron source and the proton-coupled electron transfer (PCET) greatly promotes the reduction process. Based on the energy and molecular orbital studies of the intermediate species the reduction of AuIII to AuI is shown to be thermodynamically favourable, and a low HOMO-LUMO gap of the POM-Au superstructure is advantageous for electron transfer. By modelling the reduction of three couples of AuIII ¿ AuI by the same POM unit, it is proposed that the reduced polyoxomolybdate is finally fully oxidised. The subjacent idea of using the Kabanos POM was confirmed by comprehensive experimental characterisation of POM-stabilised gold nanoparticles (AuNPs@POM). Present theoretical analysis suggests that protons have a significant influence on the final AuI to Au0 reduction step that ultimately leads to colloidal AuNPs@POM