Granite emplacement by crustal boudinage: example of the Calmayo and El Hongo plutons (Córdoba, Argentina)

This study deals with the structure and emplacement of the Calmayo and El Hongo trondhjemite plutons (Famatinian belt of Córdoba, Argentina). It provides structural data from the granites and the country rocks and a study of the magnetic fabric in the plutons. New U/Pb geochronological data yield intrusion ages of 512.1 ± 3.4 Ma and 500.6 ± 4.5 Ma for the Calmayo and El Hongo plutons respectively. The El Hongo massif and the southern part of the Calmayo trondhjemite preserve magmatic structures, whereas the northern domain of Calmayo shows the imprint of solid-state deformation. The main foliation in the country rocks outlines a boudin-like pattern at the map scale and the granites are located along boudin necks, suggesting that the emplacement of these trondhjemite plutons was linked to large-scale boudinage of the country rocks.Fil: D'eramo, Fernando Javier. Universidad Nacional de Rio Cuarto. Facultad de Ciencias Exactas, Fisicoquímicas y Naturales. Departamento de Geología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Tubía, José M.. Universidad del País Vasco; EspañaFil: Pinotti, Lucio Pedro. Universidad Nacional de Rio Cuarto. Facultad de Ciencias Exactas, Fisicoquímicas y Naturales. Departamento de Geología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Vegas, Néstor. Universidad del País Vasco; EspañaFil: Coniglio, Jorge Enrique. Universidad Nacional de Rio Cuarto. Facultad de Ciencias Exactas, Fisicoquímicas y Naturales. Departamento de Geología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Demartis, Manuel. Universidad Nacional de Rio Cuarto. Facultad de Ciencias Exactas, Fisicoquímicas y Naturales. Departamento de Geología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Aranguren, Aitor. Universidad del País Vasco; EspañaFil: Basei, Miguel. Universidade de Sao Paulo; Brasi

Anisotropy of magnetic susceptibility of the Pyrenean granites

In this paper, we report on a compilation of more than 2200 sites (more than 10,000 individual measurements) where anisotropy of magnetic susceptibility (AMS) was studied in granites from the Variscan Pyrenees. The standardization and homogenization of this information has allowed us to produce three Main Maps that synthesize all the information related with the AMS of the Pyrenean granites. We also describe the problems found during the construction of the database (variable geo-positioning, different published information, etc.). The information derived from 21 granite bodies, the database, and the synthesis maps (magnetic susceptibility, Km, and the orientation of the magnetic foliation, plane perpendicular to k3, and of the magnetic lineation, k1) allow us to see for the first time a complete image of this important kinematic and petrographic indicator

Orogenias paleozoicas en los Andes de Argentina y Chile y en la Península Antártica

Congreso Geológico Argentino (20º. 2017. San Miguel de Tucumán, Argentina). Simposio de Téctonica pre-andinaDurante el Neoproterozoico y Paleozoico, los Andes de Argentina y Chile, y desde fines del Paleozoico también la Península Antártica, formaron parte del margen SO de Gondwana. Durante este tiempo se acrecionaron a dicho margen varios fragmentos continentales de tamaño y aloctonía variable; denominados de N a S: Antofalla, Chi-Cu, Patagonia Occidental y Antártida Occidental. Estos fragmentos formaban parte de placas litosféricas, en ocasiones divididas en subplacas. La colisión de dichos fragmentos continentales con Gondwana y una última subducción bajo dicho margen, dieron lugar a 6 orogenias de extensión temporal y espacial limitada.Instituto Geológico y Minero de España, EspañaDepartamento de Geología, Universidad de Oviedo, EspañaUniversidad de Río Negro, ArgentinaServicio Geológico y Minero Argentino, ArgentinaInstituto De Bio y Geociencias Del NOA, Consejo Nacional de Investigaciones Científicas y Técnicas, ArgentinaInstituto De Bio y Geociencias Del NOA, Universidad Nacional de Salta, ArgentinaDepartamento de Geodinámica, Universidad del País Vasco, EspañaFacultad de Geología, Universidad de Barcelona, EspañaDepartamento de Geología, Universidad de Chile, ChileUniversidad Andrés Bello, ChileUnidad de Tectónica, Consejo Nacional de Investigaciones Científicas y Técnicas, ArgentinaFacultad de Geología, Universidad de Buenos Aires, ArgentinaÁrea de Geología, Universidad Rey Juan Carlos, EspañaUniversidad de Salta, ArgentinaInstituto de Investigación en Paleobiología y Geología, Universidad de Río Negro, ArgentinaInstituto de Investigación en Paleobiología y Geología, Consejo Nacional de Investigaciones Científicas y Técnicas, ArgentinaCentro de Investigaciones Geológicas, Universidad de La Plata, ArgentinaUniversidad de San Juan, ArgentinaPeer reviewe

Anisotropy of magnetic susceptibility variations in albian turbidiles from the Basque-Cantabrian basin

The first results extracted from the study of the Anisotropy of magnetic susceptibility (ASM) from 33 turbidites allocated in Basque-Cantabrian basin show the validity of the ASM as a rock fabric analysis tool to determine deposit mechanism and paleocurrents in turbidite

Geological implications of scapolite-bearing marbles in the Biscay Synclinorium

We report by the first time the finding of scapolite-bearing marbles in the Southern limb of the Biscay Synclinorium (Basque-Cantabrian basin). Marbles are found as layers or fragments in Triassic evaporites. I. Evaporitic rocks an antiform cut acrossby crop out in transversal faults. The presence of such marbles lead us to propose a new location for the prolongation of the North Pyrenean Fault in western sectors of the Basque-Cantabrian bassi

Inversion tectonics in the central part of the Basque Arc (Basque-Cantabrian basin)

We report the existence of a thrust system in the central part of the Basque Arc (Basque-Cantabrian basin, Guipúzcoa). From bottom to top, the thrust system is formed by theAia, Pagoeta and Azpeitia allochthonous sheets. The kinematic and structural analysis provides a top to the NE movement, and reveals the widespread reactivation of normal faults during the Pyrenean inversion tectonic

Magmatism coeval with lower Paleozoic shelf basins in NW-Argentina (Tastil batholith): Constraints on current stratigraphic and tectonic interpretations

The Tastil batholith (Eastern Cordillera, NW Argentina) holds relevant keys for interpreting the tectonic evolution of the Central Andes basement since it has always been interpreted as the subcrop of the Cambrian and Lower Ordovician basins in the Eastern Cordillera. However, in the Angosto de la Quesera section, the batholith intrudes sandstones underlying a fossiliferous Lower Tremadocian conglomerate containing Tastil granite pebbles. The precise assignation of the sandstones intruded by the granite to Cambrian Mesón Group or to the Uppermost Cambrian–Lower Tremadocian Santa Victoria Group is a key for refining the relationships between magmatic and sedimentary units. The ages of 526 Ma and 517 Ma (U/Pb, zircons) obtained from two facies of the batholith are coherent with the proposal of including these sandstones in the Mesón Group. However, the lithologic features and fossil content point to an affinity with the basal units of the Santa Victoria Group according to sedimentologic and stratigraphic studies ruled out by other authors. The intrusive relationships between the Tastil batholith and the Lower Paleozoic sandstones indicates the batholith is coeval with the Mesón and/or Santa Victoria groups basins instead of being its subcrop, which strongly contradicts previous proposals about basement evolution along the Lower Paleozoic margin of Gondwana. Therefore, the genesis and emplacement of the Tastil batholith must be related to the development of the Lower Paleozoic shelf basins rather than with the final stages of Puncoviscana-type basin evolution. The basement of central and northern Argentina records a wide spectrum of sedimentary, deformational, magmatic and metamorphic processes at a variety of crust levels during the Early Paleozoic. Tastil batholith emplacement and exhumation in the Eastern Cordillera represent shallower crustal expressions of the plutonic and high-T–low-P metamorphic events at deeper levels in the basement now exposed mainly in eastern Puna and Pampean Ranges.Fil: Hongn, Fernando Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Salta. Instituto de Bio y Geociencias del Noroeste Argentino; Argentina. Universidad Nacional de Salta; ArgentinaFil: Tubía, José M.. Universidad del Pais Vasco; EspañaFil: Aranguren, Aitor. Universidad del Pais Vasco; EspañaFil: Vegas, Néstor. Universidad del Pais Vasco; EspañaFil: Mon, Ricardo. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Tucumán; ArgentinaFil: Dunning, Gregory R.. Memorial University Of Newfoundland; Canad

Seismic Study of the Iberian Crust, ESCI-Betics survey

Two land seismic profiles across the Betic Chain imaged the deep structure of the crust belonging to two different crustal domains. To the north, one profile samples the crust of the Variscan Iberian Massif that underlies the sedimentary cover of both the Guadalquivir foreland basin and the South Iberian crustal domain. A second profile crosses the Alpine metamorphic complexes of the Betics.Comisión Interministerial de Ciencia y Tecnología - CICYT.-- Dirección General de Investigación Científica y Técnica - DGICYT.--Peer reviewe

Anisotropy of magnetic susceptibility of the Pyrenean granites

<p>In this paper, we report on a compilation of more than 2200 sites (more than 10,000 individual measurements) where anisotropy of magnetic susceptibility (AMS) was studied in granites from the Variscan Pyrenees. The standardization and homogenization of this information has allowed us to produce three <a href="https://doi.org/10.1080/17445647.2017.1302364" target="_blank">Main Maps</a> that synthesize all the information related with the AMS of the Pyrenean granites. We also describe the problems found during the construction of the database (variable geo-positioning, different published information, etc.). The information derived from 21 granite bodies, the database, and the synthesis maps (magnetic susceptibility, Km, and the orientation of the magnetic foliation, plane perpendicular to k3, and of the magnetic lineation, k1) allow us to see for the first time a complete image of this important kinematic and petrographic indicator.</p