Integrante

Foto Ibañez Natalia-400pxh
Natalia Belén
Ibañez
Licenciada en Ciencias Geológicas
Becaria doctoral
Ayudante de 2da
Geología de Yacimientos
Una breve descripción de actividad desarrollada: Estudio metalogenético de vetas de Pb-Ag-Zn (Cu-Au) del Distrito Castaño Viejo (Cordillera Frontal, San Juan) y su potencial como fuente de metales críticos
ibaneznataliab@gmail.com

Integrante

Herrmann Carlos-500px
Carlos
Herrmann
Dr. en Ciencias Geológicas
Profesor Adjunto
Geología de Yacimientos - Geología Minera
Publicaciones, investigaciones y docencia principalmente sobre los siguientes temas: Modelos geoambientales de depósitos minerales, Yacimientos no metalíferos y rocas, Yacimientos Argentinos, Metalogénesis para la prospección
carjor504@hotmail.com

Integrante

Premio Estímulo-Bellante-03-600pxh
Micaela Belén
Bellante
Lic. en Ciencias Geológicas
Becaria doctoral
Ayudante de 2da
Paleomagnetismo
Paleogeografía del Cratón del Río de La Plata en el Paleo, Meso y Neoproterozoico.
micabellante@gmail.com

A new ‘archaeohyracid’ (Notoungulata, Typotheria) from the Eocene of north-western Argentina: anatomy, phylogenetic relationships and evolutionary implications

Agostina Ferro, Daniel A. García-López, Luis S. Saade, Pablo J. Alonso-Muruaga, Agustín Scanferla
2 023
Journal of Systematic Palaeontology Volume 21, 2023 - Issue 1
Here we describe a new notoungulate taxon, Pascualhyrax irqi sp. nov., from Eocene levels of north-western Argentina. The materials studied include cranial and dental remains and were exhumed in sediments of the Quebrada de los Colorados Formation, corresponding to the late middle Eocene (Bartonian). General traits of the referred specimens (e.g. hypsodont postcanines, nasal bulge) point to a close relationship with different typotherian taxa traditionally included among the paraphyletic ‘Archaeohyracidae’. In turn, a combination of characters indicates that the new material represents a new taxon (e.g. smaller size, deep ectoflexus in upper molars in all wear stages, maxillary process extending posterior to the caudal end of the nasals). A phylogenetic analysis was performed, based in a previously published matrix and the addition of new characters, resulting in a close relationship of Pascualhyrax irqi sp. nov. with different ‘Archaeohyracidae’ of Oligocene radiation. This fact shows the early expression of some characters until now only known for later forms, and developed in the context of a recently acknowledged diversity of hypsodont typotherians in north-western Argentina. Regarding other evolutionary issues, the strong similitude of the juvenile specimens referred to Pascualhyrax irqi sp. nov. with adult individuals of the Neogene clade Pachyrukhinae, indicates possible heterochronic (paedomorphic) traits in the later forms.

Cerro Granito Granitoids: lithology, 40Ar/39Ar geochronology and regional correlations

Monica Graciela Lopez de Luchi, Eduardo Rossello, Carmen I. Martínez Dopico, Gilles Ruffet
2 023
Revista de la Asociación Geológica Argentina, 80(1) (2023), 21-36.
El cerro Granito es una lomada de contorno ovalado, con una altura máxima de 890 m s.n.m., que aflora en medio de capas jurásicas a modo de un anticlinorio, jalonando el lineamiento regional de la Dorsal Huincul que subdivide la cuenca Neuquina en dos partes. El núcleo del Cerro Granito está integrado mayormente por (1) granodioritas grises biotítico-anfibólicas, (2) monzogranitos gris claro, biotítico-epidóticos, (3) monzogranitos a leucogranitos gris rosado biotíticos porfiríticos (4) tonalitas grises biotíticas porfiríticas y (5) diques de espesor decamétrico de andesitas grises, ligeramente verde-violáceas, de rumbo aproximado NO-SE. Desde el sector central y hacia el NE, se reconoce un fracturamiento intenso y un predominio de diques aplopegmatíticos de rumbo NNE-SSO. En el presente trabajo, se aportan nuevos datos petrográficos de cinco facies magmáticas, dos de las cuales fueron datadas radiométri-camente. La edad 40Ar/39Ar anterior a 281 Ma para la granodiorita biotítico anfibólica junto con la existencia de una facies de tonalita biotítica porfírítica, refuerzan la propuesta de la vinculación de las unidades plutónicas del cerro Granito con el Complejo plutónico Chachil. Este evento ígneo sería equivalente al expuesto en el Batolito Costero Chileno y resulta anterior al clímax del magmatismo Choiyoi. Al cabo de aproximadamente 90 Ma. el próximo registro magmático corresponde a un dique andesítico lo que confirma que la exhumación final de los granitoides fue posterior a los 190 Ma (Sinemuriano - Pliesbachiano) y, desde todo punto de vista, anterior a la depositación de las secuencias marinas de la Formación Lajas (Toarciano).
Cerro Granito is an oval shaped hill, with a maximum height of 890 m above sea level, which outcrops in the middle of Jurassic layers as an anticlinorium, marking out the regional line of the Huincul Ridge that subdivides the Neuquén basin in two. The core of Cerro Granito is composed mainly of (1) biotitic-amphibolic gray granodiorites, (2) biotitic-epidotic light gray monzogranites, (3) biotitic porphyritic pinkish gray leucogranites (4) biotitic porphyritic gray tonalites and (5) decametric dikes of gray andesites, slightly green purple, with an approximate NW-SE strike. From the central sector and towards the NE, intense fracturing, and a predominance of aplopegmatitic dikes trending NNE are recognized. In the present work, new petrographic data of five magmatic facies are provided, two of which were radiometrically dated. The 40Ar/39Ar age older than 281 Ma for the amphibolic biotitic granodiorite, together with the existence of a porphyritic biotitic tonalite facies, reinforce the proposal of linking the plutonic units of Cerro Granito with the Chachil Plutonic Complex. This igneous event would be equivalent to the one exposed in the Chilean Coastal Batholith and pre-dates the climax of the Choiyoi event. After approximately 90 Ma, the next magmatic record corresponds to an andesitic dike, which confirms that the final exhumation of the granitoids was after 190 Ma (Sinemurian - Pliesbachian) and, from all points of view, prior to the deposition of the marine sequences of the Toarcian Lajas Formation.

Pub-Rossello-Cerro Granito Granitoids

Petrografía cerámica aplicada al estudio de la Metalurgia en el Noroeste Argentino Prehispánico

Geraldine Gluzman, E. Beatriz Maisonnave
2 020
Chungará (Arica) vol.52 no.4 Arica Dec. 2020
La producción de cerámicas metalúrgicas prehispánicas en el Noroeste de Argentina ha sido un tema poco abordado desde los estudios arqueometalúrgicos tradicionales. Sin embargo, estas cerámicas, principalmente moldes y crisoles, constituyeron insumos indispensables de la tecnología más compleja llevada a cabo por las sociedades prehispánicas del área, como lo fue la producción de bienes metálicos. Evaluadas en ciertos aspectos específicos, poco se ha indagado acerca de la caracterización de sus pastas cerámicas. En este artículo presentamos un análisis de cerámicas metalúrgicas de sitios arqueológicos a partir de estudios petrográficos. La muestra, compuesta de 10 ejemplares, posee cerámicas del área valliserrana, cubriendo desde la provincia de Jujuy hasta la provincia de San Juan, enriqueciendo el análisis con descripciones de piezas provenientes de otras regiones del noroeste argentino así como del Norte de Chile. En esta primera etapa de comparación regional, los resultados indican que la morfología de las cerámicas metalúrgicas posee una importante similitud en formas y proporciones, mientras que la petrografía cerámica da cuenta de una amplia variabilidad en tamaño y naturaleza de inclusiones, grado de porosidad y porcentaje de matriz, reflejando decisiones tecnológicas influidas por la geología local y constreñidas por el uso como insumos productivos.
Pre-Hispanic production of metallurgical ceramics in Northwest Argentina has been a subject little discussed in traditional archaeometallurgical studies. Nevertheless, these ceramics, mainly molds and crucibles, were indispensable inputs of the most complex technology carried out by the pre-Hispanic societies of the area, as was the production of metallic goods. Although they have been analyzed in certain specific aspects, little research has been done on the characterization of their ceramic fabric. In this paper, we present an analysis of metallurgical ceramics from archaeological sites in the area through petrographic procedures. The sample, composed of ten specimens, contains ceramics from the Valliserrana area, covering from the province of Jujuy up to the province of San Juan. The analysis is enriched with descriptions of objects from other regions of Northwest Argentina as well as from the North of Chile. In this first stage towards a regional comparison, the results indicate that, at a regional level, the morphology of metallurgical ceramics shows an important similarity in forms and proportions, while the ceramic petrography accounts for a wide range of variability in terms of size and nature of inclusions, degree of porosity, and percentage of matrix, reflecting technological decisions, which were influenced by local geology and constrained by use as production inputs.
Pub Maisonnave-Petrografía cerámica aplicada al

Raman spectroscopy in experimental rock art: Improving the study of ancient paintings

Ivana Laura Ozán, Sebastián Oriolo, María Ana Castro, Andrés Latorre
2 020
Raman spectroscopy - Volume51, Issue11 November 2020 Pages 2272-2289
The present work analyzes Raman spectra of red, white, and black experimental paintings manufactured according to archeological and ethnographical data from Patagonia (South America), in order to provide reference patterns to better understand ancient signatures of rock art. Methodological insights are also presented, evaluating pitfalls and advantages of Raman spectroscopy. For this purpose, different pigments (hematite, gypsum, charcoal) mixed with binders and additives (Lama guanicoe fat, blood, urine, saliva, gypsum) were combined. Results show that, despite its high-spatial resolution, Raman analysis shows painting spectra often reflecting multicomponent signals at micrometer-scale. Results also indicate that fat and blood show well-defined spectra in paintings, whereas saliva and urine have negligible signatures, so a relatively high and low archeological preservation is expected, respectively. On the other hand, laser-related thermoalteration processes of fat and blood binders are triggered by the presence of hematite. This thermoalteration promotes conspicuous signatures in fat and blood binders related to disordered CC bonds (ca. 1,330 and 1,566 cm−1), which are also found in charcoal. Therefore, disordered carbon in the Raman spectra of rock art may not necessarily imply the presence of charcoal-bearing pigments but may also result from thermoalteration of organic materials. Evidence of blood migration through rock porosity is registered as well, with significant implications for rock art preservation, composition, and dating.
Pub-Oriolo-Raman spectroscopy in experimental

Thrust-related metamorphism in Carboniferous slates of southern Patagonia (South America): the fate of forearc successions

Rodrigo Javier Suárez, Pablo Diego González, Sebastián Oriolo, Martín Nazareno Parada, Miguel Esteban Ramos, Matías C. Ghiglione, Claudia Zaffarana, Juan Albano and Juan José Ponce
2 024
Journal of the Geological Society Volume 181, 17 May 2024
The Devonian to early Carboniferous western margin of Patagonia (South America) includes a NW–SE-trending magmatic arc associated with a NE-dipping palaeo-subduction zone. Along the Andean region of southern Patagonia, the Eastern Andean Metamorphic Complex developed in a forearc position and consists of a succession of very low- to low-grade metaturbidite–metabasic rocks emplaced from the Devonian to Carboniferous. There are significant uncertainties surrounding this metamorphic complex, mainly related to the tectonosedimentary setting of the basin and the subsequent conditions of deformation and metamorphism, which hinder our understanding of the orogenic architecture. To reveal the links between tectonics and metamorphism, we conducted a structural analysis and sampled metapelites to measure the illite crystallinity along a regional structural cross-section in the Eastern Andean Metamorphic Complex. Our analysis reveals broadly lower to upper anchizonal metamorphism roughly synchronous with deformation along northwards-verging thrusts. These findings support the development of a forearc hyperextended basin that was subsequently closed during the Gondwanide Orogeny (late Paleozoic), a model that reconciles previous proposals suggesting passive margin v. back-arc basin models. This closure led to the emplacement of supra-subduction zone ophiolites and turbidites over the continent through the landwards migration of brittle–ductile reverse shear zones.