Person:
Galindo Francisco, María Del Carmen

First Name

María Del Carmen

Last Name

Galindo Francisco

URI

https://hdl.handle.net/20.500.14352/81297

Affiliation

Universidad Complutense de Madrid

Faculty / Institute

Ciencias Geológicas

Department

Mineralogía y Petrología

Area

Petrología y Geoquímica

Identifiers

Full item page

Search Results

Now showing 1 - 10 of 44

Síntesis geocronológica de la evolución paleozoica inferior del borde sur occidental de Gondwana en las Sierras Pampeanas, Argentina
(Acta geológica hispánica, 1997) Baldo, Edgardo G.; Saavedra, Julio; Rapela, Carlos W.; Pankhurst, R.J.; Casquet Martín, César; Galindo Francisco, María Del Carmen
Las Sierras Pampeanas Argentinas constituyen un buen registro de la evolución Pre-Devónica del margen sur occidental del Gondwana. Los trabajos multidisciplinarios recientes y especialmente la información geocronológica, recolectada a lo largo de una transecta E-W de aproximadamente unos 500 km, permiten precisar la edad y los rasgos geológicos de los dos principales ciclos tectono-magmáticos involucrados en la evolución paleozoica inferior de esta parte del basamento argentino. El Ciclo Orogénico Pampeano comienza con una etapa de sedimentación en un margen pasivo (560-530 Ma), que evoluciona hacia una situación de margen activo con generación de un arco magmático tipo Andino, a los 533 - 528 Ma. El ciclo finaliza hacia los 523 Ma. en una colisión de tipo ortogonal, con un importante engrosamiento cortical, anatexis regional y generación de granitos "S". El "Ciclo Orogénico Famatiniano" se inicia a los 499-496 Ma y se caracteriza por la implantación de un arco magmático intemo de tipo trondhjemitico, seguido hacia el oeste por un importante arco magmático externo, contemporáneo con el anterior y formado por granodioritas de tipo "1" y grandes batolitos graníticos de tipo "S". Durante el Famatiniano tiene también lugar la formación de una cuenca de retroarco ensiálica con magmatismo básico. El final de este ciclo (450-420 Ma) está marcado por el desarrollo de importantes fajas de milonitización que marcan la colisión oblicua del Terreno Precordillera respecto al margen de Gondwana
The evolution of a mid-crustal thermal aureole at Cerro Toro, Sierra de Famatina, NW Argentina
(Lithos (Oslo. Print), 2014) Alasino, Pablo H.; Casquet Martín, César; Larrovere, M.A.; Pankhurst, R.J.; Galindo Francisco, María Del Carmen; Dahlquist, Juan A.; Baldo, Edgardo G.; Rapela, Carlos W.
A sheeted tonalite complex at Cerro Toro in western Sierra de Famatina, Argentina, was emplaced in the middle crust during an early phase of the Ordovician Famatinian orogeny. The intrusion produced a large-scale thermal aureole that provoked significant melting of the host rocks and hybridization of the anatectic melts with the tonalitic magmas. Three zones were distinguished in a cross-section: (1) an external zone consisting of metatexitic gneisses, amphibolites and minor tonalites, (2) an intermediate zone formed by screens of highly melted gneisses and amphibolites lying between the tonalite sheets: stoped blocks of gneisses within the tonalite sheets, small bodies of metagabbro and hybrid rocks are common in this zone, (3) an internal zone formed almost exclusively of massive tonalite. Incongruent melting of biotite in gneisses of the intermediate zone produced abundant cordierite and garnet; anatectic granitoids developed in the innermost part at 750–800ºC and ca. 5kbar. High water activities within this zone eventually promoted significant melting of plagioclase + quartz in the gneisses. Pooling of anatectic magmas resulted in allochthonous bodies of variable size either concordant or discordant to the regional structural grain, and part were retained in or close to the residuum. Allochthonous granitoids did not reach isotopic equilibrium with the source protolith probably due to fast extraction of the melts. The Cerro Toro contact aureole shows that assimilation of metasedimentary rocks through partial melting can be an important mechanism during emplacement of tonalitic magmas at middle crust levels. Thus the chemistry of cordilleran magma can be modified as they rise through the crust.
U–Pb SHRIMP zircon dating of Grenvillian metamorphism in Western Sierras Pampeanas (Argentina): Correlation with the Arequipa-Antofalla craton and constraints on the extent of the Precordillera Terrane
(Gondwana research, 2006) Casquet Martín, César; Pankhurst, R.J.; Fanning, C.M.; Baldo, Edgardo G.; Galindo Francisco, María Del Carmen; Rapela, Carlos W.; González Casado, José Manuel; Dahlquist, Juan A.
Metamorphism of Grenvillian age (ca. 1.2 Ga; U–Pb zircon dating) is recognized for the first time in the Western Sierras Pampeanas (Sierra de Maz). Conditions reached granulite facies (ca. 780 °C and ca. 780 MPa). Comparing geochronological and petrological characteristics with other outcrops of Mesoproterozoic basement, particularly in the northern and central Arequipa-Antofalla craton, we suggest that these regions were part of a single continental crustal block from Mesoproterozoic times, and thus autochthonous or parautochthonous to Gondwana.
Datación U-Pb SHRIMP de circones detríticos en paranfibolitas neoproterozoicas de las secuencia Difunta Correa (Sierras Pampeanas Occidentales, Argentina)
(Geogaceta, 2005) Rapela, Carlos W.; Pankhurst, R.J.; Casquet Martín, César; Fanning, C.M.; Galindo Francisco, María Del Carmen; Baldo, Edgardo G.
The Neoproterozoic Difunta Correa meta-sedimentary sequence (DCSS) of Western Sierras Pampeanas is a cover to a rejuvenated Grenvillian basement. The Western Sierras Pampeanas are allegedly part of the exotic Precordillera Terrane, which was accreted to the proto-Andean margin of Gondwana in lower Palaeozoic times. A para-amphibolite from this sedimentary sequence contains abundant zircons mostly consisting of detrital igneous cores with a metamorphic overgrowth. The latter formed at 439±34 Ma, i.e., during the Famatinian orogeny, although mantles are also found with mixed Grenvillian - Ordovician ages due to Pb-loss. Ages of igneous cores are ~ 625 Ma , 1050-1150 Ma and 1200-1500 Ma with a peak at c. 1.4 Ga. The ~ 625 Ma group zircon is of Gondwanan provenance and this age is an upper value for the age of the host amphibolite. An age between 580 Ma and 620 Ma is inferred for the DCSS. The provenance of zircons between 1.05 Ga and c. 1.2 Ga probably lies in the underlying Grenvillian basement. However zircons older than 1.2 Ga were derived from an unexposed area: palaeogeographical considerations suggest that this area could be either in Laurentia (trans-Laurentia belt) or in southern Amazonia (Rondonia- San Ignacio belt), both 1.3-1.5 Ga in age.
The Sierra Norte-Ambargasta batholith: Late Ediacarane-Early Cambrian magmatism associated with Pampean transpressional tectonics
(Journal of South American earth sciences, 2013) Iannizzotto, Noelia F.; Rapela, Carlos W.; Baldo, Edgardo G.; Galindo Francisco, María Del Carmen; Fanning, C.M.; Pankhurst, R.J.
The Sierra Norte-Ambargasta batholith is one of the largest plutonic expressions of the Pampean orogeny in western Argentina. A thorough petrographic, geochemical, isotopic (Sr and Nd) and geochronological (UePb SHRIMP) study is reported. The batholith comprises granitoid rocks that may be subdivided into those affected by Pampean D2 dextral shearing and mylonization and those emplaced after deformation had ceased; representative samples gave UePb zircon ages of 537 ±4 Ma and 530 ±4 Ma respectively. The earlier, dominant, groupwere derived largely frommetaluminous calc-alkaline subduction-related magmas, whereas the late granites are peraluminous. However, all have relatively high initial 87Sr/86Sr ratios (0.706 to at least 0.710, strongly negative εNdt values (-1.7 to -5.9) and, in some cases inherited 600 Ma and 970 Ma zircon, similar to the isotopic and zircon provenance seen in the metamorphic host rocks. A high degree of contamination of the magmas, possibly anatexis in the case of the post-mylonite granite, is related to emplacement during the latestage transpressional docking of the Pampean terrane against the Rio de la Plata craton. The absence of detrital zircon derived from the craton in either the Pampean metasedimentary host rocks or the batholith supports this collisional model for the Pampean orogen.
The Faja Eruptiva of the Eastern Puna and the Sierra de Calalaste, NW Argentina: U–Pb zircon chronology of the early Famatinan orogeny
(Journal of iberian geology, 2021) Casquet Martín, César; Alasino, Pablo H.; Galindo Francisco, María Del Carmen; Dahlquist, Juan A.; Baldo, Edgardo G.; Ramacciotti, Carlos; Verdecchia, Sebastián; Larrovere, Mariano Alexis; Rapela, Carlos W.; Recio, C.
The Famatinian is a segment of the Ordovician Terra Australis accretionary orogen that stretched along the SW Margin of Gondwana from Australia to Colombia. The present knowledge of this orogenic segment still is incomplete. We present geochemistry and U–Pb SHRIMP zircon geochronology of igneous and metamorphic rocks from the Central Famatinian Domain, one of the several domains recognized by Rapela et al. (Earth Sci Rev 187: 259–285. https://doi.org/10.1016/j.earscirev.2018.10.006) that includes the northern Sierras Pampeanas and the southern Puna of North West Argentina. Six samples of igneous rocks (peraluminous granitoids, mafic and felsic rocks, volcanic/subvolcanic rocks) and six samples of associated meta-sedimentary rocks, all from the Puna were dated and chemically analysed. The results indicate that the Central Famatinian Domain is in turn a composite domain that includes a Cordilleran-type magmatic arc (ca. 470 Ma) and a yuxtaposed fault-bounded older terrain formed in an extensional setting at the very start of the Famatinian orogeny, between 480 and 485 Ma, i.e., shortly after the SW Gondwana margin switched from passive to active. This short period of extension with related sedimentation, volcanism and mainly granitoid plutonism has not been previously recognised. It occurred before the Cordilleran-type magmatic arc -that resulted from a magmatic flare-up between ca. 473 and 468 Ma-, set up coincident with a contractional phase. The evidence confirms that accretionary orogeny results from tectonic switching (pull–push orogeny) and that the extensional and contractional phases are of relatively short duration.
The Arequipa Massif of Peru: New SHRIMP and isotope constraints on a Paleoproterozoic inlier in the Grenvillian orogen
(Journal of South American earth sciences, 2010) Casquet Martín, César; Fanning, C.M.; Galindo Francisco, María Del Carmen; Pankhurst, R.J.; Rapela, Carlos W.; Torres , P.
The enigmatic Arequipa Massif of southwestern Peru is an outcrop of Andean basement that underwent Grenville-age metamorphism, and as such it is important for the better constraint of Laurentia–Amazonia ties in Rodinia reconstruction models. U–Pb SHRIMP zircon dating has yielded new evidence on the evolution of the Massif between Middle Paleoproterozoic and Early Paleozoic. The oldest rock-forming events occurred in major orogenic events between ca. 1.79 and 2.1 Ga (Orosirian to Rhyacian), involving early magmatism (1.89–2.1 Ga, presumably emplaced through partly Archaean continental crust), sedimentation of a thick sequence of terrigenous sediments, UHT metamorphism at ca. 1.87 Ga, and late felsic magmatism at ca. 1.79 Ga. The Atico sedimentary basin developed in the Late-Mesoproterozoic and detrital zircons were fed from a source area similar to the high-grade Paleoproterozoic basement, but also from an unknown source that provided Mesoproterozoic zircons of 1200–1600 Ma. The Grenville-age metamorphism was of low-P type; it both reworked the Paleoproterozoic rocks and also affected the Atico sedimentary rocks. Metamorphism was diachronous: ca. 1040 Ma in the Quilca and Camaná areas and in the San Juán Marcona domain, 940 ± 6 Ma in the Mollendo area, and between 1000 and 850 Ma in the Atico domain. These metamorphic domains are probably tectonically juxtaposed. Comparison with coeval Grenvillian processes in Laurentia and in southern Amazonia raises the possibility that Grenvillian metamorphism in the Arequipa Massif resulted from extension and not from collision. The Arequipa Massif experienced Ordovician–Silurian magmatism at ca. 465 Ma, including anorthosites formerly considered to be Grenvillian, and high-T metamorphism deep within the magmatic arc. Focused retrogression along shear zones or unconformities took place between 430 and 440 Ma.
The Mesoproterozoic Maz terrane in the Western Sierras Pampeanas, Argentina, equivalent to the Arequipa–Antofalla block of southern Peru? Implications for West Gondwana margin evolution
(Gondwana research, 2008) Casquet Martín, César; Pankhurst, R.J.; Rapela, Carlos W.; Galindo Francisco, María Del Carmen; Fanning, C.M.; Chiaradia, Massimo; Baldo, Edgardo G.; González Casado, José Manuel; Dahlquist, Juan A.
The rocks of Sierra de Maz and Sierra del Espinal (Western Sierras Pampeanas) represent pre-Famatinian (Ordovician) basement. Isotope compositions (Nd and Pb) of metasedimentary rocks and SHRIMP U–Pb dating of detrital zircons, combined with other geological evidence, show that three parallel N–S domains can be recognized. The central Maz Domain contains pre-Grenvillian metasedimentary rocks deposited between 1.2 and 1.6 Ga, that underwent Grenvillian granulite facies metamorphism and were intruded by mafic igneous rocks and massif-type anorthosites. Metasedimentary rocks have high Nd TDM ages (1.7–2.7 Ga) and very radiogenic Pb (μ=9.8–10.2), suggesting provenance from reworked early Proterozoic or Archean continental crust. The domains to the east and west of the Maz Domain consist of three metasedimentary sequences with Nd TDM ages between 1.2 and 1.6 Ga and variably radiogenic Pb (μ=9.6–10.0). U–Pb SHRIMP dating of detrital zircons, Nd TDM model ages and comparison with other data suggest that these sequences are post-Grenvillian, i.e., Neoproterozoic and/or early Paleozoic. The Maz Domain is interpreted as a suspect terrane similar to the northern Arequipa–Antofalla craton that forms the basement of the Central Andes; both underwent Grenville-age orogeny and were probably once continuous along the western margin of Amazonia (West Gondwana).
The Western Sierras Pampeanas: Protracted Grenville-age history (1330–1030 Ma) of intra-oceanic arcs, subduction–accretion at continental-edge and AMCG intraplate magmatism
(Journal of South American earth sciences, 2010) Rapela, Carlos W.; Pankhurst, R.J.; Casquet Martín, César; Baldo, Edgardo G.; Galindo Francisco, María Del Carmen; Fanning, C.M.; Dahlquist, Juan A.
New U–Pb SHRIMP zircon ages combined with geochemical and isotope investigation in the Sierra de Maz and Sierra de Pie de Palo and a xenolith of the Precordillera basement (Ullún), provides insight into the identification of major Grenville-age tectonomagmatic events and their timing in the Western Sierras Pampeanas. The study reveals two contrasting scenarios that evolved separately during the 300 Ma long history: Sierra de Maz, which was always part of a continental crust, and the juvenile oceanic arc and back-arc sector of Sierra de Pie de Palo and Ullún. The oldest rocks are the Andino-type granitic orthogneisses of Sierra de Maz (1330–1260 Ma) and associated subalkaline basic rocks, that were part of an active continental margin developed in a Paleoproterozoic crust. Amphibolite facies metamorphism affected the orthogneisses at ca. 1175 Ma, while granulite facies was attained in neighbouring meta-sediments and basic granulites. Interruption of continental-edge magmatism and high-grade metamorphism is interpreted as related to an arc–continental collision dated by zircon overgrowths at 1170–1230 Ma. The next event consisted of massif-type anorthosites and related meta-jotunites, meta-mangerites (1092 ± 6 Ma) and meta-granites (1086 ± 10 Ma) that define an AMCG complex in Sierra de Maz. The emplacement of these mantle-derived magmas during an extensional episode produced a widespread thermal overprint at ca. 1095 Ma in neighbouring country rocks. In constrast, juvenile oceanic arc and back-arc complexes dominated the Sierra de Pie de Palo–Ullún sector, that was fully developed ca. 1200 Ma (1196 ± 8 Ma metagabbro). A new episode of oceanic arc magmatism at 1165 Ma was roughly coeval with the amphibolite high-grade metamorphism of Sierra de Maz, indicating that these two sectors underwent independent geodynamic scenarios at this age. Two more episodes of arc subduction are registered in the Pie de Palo–Ullún sector: (i) 1110 ± 10 Ma orthogneisses and basic amphibolites with geochemical fingerprints of emplacement in a more mature crust, and (ii) a 1027 ± 17 Ma TTG juvenile suite, which is the youngest Grenville-age magmatic event registered in the Western Sierras Pampeanas. The geodynamic history in both study areas reveals a complex orogenic evolution, dominated by convergent tectonics and accretion of juvenile oceanic arcs to the continent.
The Río de la Plata craton and the assembly of SW Gondwana
(Earth-science reviews, 2007) Rapela, Carlos W.; Pankhurst, R.J.; Casquet Martín, César; Fanning, C.M.; Baldo, Edgardo G.; González Casado, José Manuel; Galindo Francisco, María Del Carmen; Dahlquist, Juan A.
The extent and nature of the Archaean–Palaeoproterozoic craton of Río de la Plata of southern South America, a major but poorly understood crustal component in Neoproterozoic plate reconstructions, as well as the depositional, metamorphic and magmatic history of the surrounding orogenic belts, are reviewed and reassessed, in part through the analysis of material recovered from deep boreholes in western Argentina that penetrated Palaeozoic cover into basement. U–Pb SHRIMP zircon ages for these samples of 2162±6 Ma (diorite), 2189±14 Ma (amphibolitic schist) and 2088±6 Ma (granite) encompass the range of ages determined for the major Palaeoproterozoic orogenic events in the exposed parts of the craton close to the Atlantic coasts of Uruguay and Argentina. Taken together with the geochemical and Nd-isotope characteristics of these samples and an olivine gabbro from a further borehole that failed to yield zircon, these results strongly suggest that the Río de la Plata craton is extremely uniform in its dominant chrono-tectonic and lithological make-up, and that it extends westwards as far as the 535–520 Ma Pampean orogenic belt, against which it probably has a fault contact. U–Pb SHRIMP zircon detrital age patterns are presented for representative metasedimentary samples from the craton cover in the Tandilia belt of eastern Argentina, and from the Pampean (Cambrian) and Famatinian (Ordovician) belts to the west of the craton. Whereas the oldest cover rocks in Tandilia clearly show material derived from the underlying craton, such detritus only appears in the younger (Ordovician) units to the west. Sedimentary protoliths in the Pampean belt were dominated by Neoproterozoic (broadly ∼600 Ma) and late Mesoproterozoic (broadly ∼1100 Ma) provenance, and derivation from the Río de la Plata craton is highly unlikely. Regional considerations, including previously published zircon data, palaeocurrent and structural data, suggest that these rocks must have had an origin within Gondwana-forming blocks, for which the closest identifiable sources are ‘Brazilian’ and ‘African’ (Namaqua–Natal). Consequently, the preferred model for the Pampean orogeny is that the Río de la Plata craton reached its present position by large-scale dextral strike-slip movement against fore-arc sedimentary sequences that had developed on the southern and western margins of the Kalahari craton during the Early Cambrian. In the final stage the displaced sedimentary sequences outboard of the RPC collided with the Mesoproterozoic Western Sierras Pampeanas terrane, which was at the time attached to the large Amazonia craton and other smaller continental blocks, such as Arequipa–Antofalla and Río Apa. Protracted relative displacement of the RPC after the Pampean Orogeny led to its final position.