Person: Galindo Francisco, María Del Carmen
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First Name
María Del Carmen
Last Name
Galindo Francisco
Affiliation
Universidad Complutense de Madrid
Faculty / Institute
Ciencias Geológicas
Department
Mineralogía y Petrología
Area
Petrología y Geoquímica
Identifiers
33 results
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Item The Difunta Correa metasedimentary sequence (NW Argentina): relict of a Neoproterozoic platform? — elemental and Sr-Nd isotope evidence(Revista mexicana de ciencias geológicas, 2015) Ramacciotti, Carlos; Casquet Martín, César; Baldo, Edgardo G.; Galindo Francisco, María Del CarmenThe Sierra de Pie de Palo (Western Sierras Pampeanas, Argentina) in the Andean foreland is mainly formed by a Mesoproterozoic basement and an Ediacaran metasedimentary over referred to as the Difunta Correa metasedimentary sequence. The latter is key to understanding the characteristics of this region prior to the early Cambrian assembly of SW Gondwana. It is composed of low- to medium grade metamorphic rocks (metasandstones, mica-chists, Ca-pelitic schists, metaconglomerates, marbles and less abundant amphibolites) that can be grouped into four informal lithostratigraphic units. The chemical composition of these rocks allows to classify the siliciclastic protoliths as shales, Fe-shales and immature sandstones (wackes, sub-litharenites, litharenites and Fe-sandstones). The sediments were derived from an evolved felsic to intermediate continental source and were deposited on a continental passive margin overlaying a Mesoproterozoic basement that crops out at several places of the Western Sierras Pampeanas. Thick marine carbonate beds with seawater isotope composition, phosphatic clasts and the lack of contemporaneous, arc related igneous rocks, also support a passive margin sedimentation. Phosphatic clasts within metaconglomerates are described for the first time in the Sierras Pampeanas and were probably formed after an important Neoproterozoic glaciation (Marinoan). We further suggest, based on our data and previous works, that the passive margin probably belonged to the Paleoproterozoic MARA (acronym of Maz, Arequipa, Río Apa) continental block. MARA, which remained juxtaposed to Laurentia since the middle to late Mesoproterozoic orogenies until its eventual drifting in the late Neoproterozoic, finally accreted to SW Gondwana in early Cambrian times during the Pampean orogeny.Item 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.Item The strongly peraluminous A-type granites of the Characato suite (Achala batholith), Sierras Pampeanas, Argentina: Evidence of Devonian-Carboniferous crustal reworking(Journal of South American Earth Sciences, 2018) Morales Cámera, Matías M.; Dahlquist, Juan A.; Ramacciotti, Carlos D.; Galindo Francisco, María Del Carmen; Basei, Miguel A.S.; Zandomeni, Priscila S.; Macchioli Grande, MarcosThe largest igneous body in the Sierras Pampeanas (the Achala batholith) is composed by several magmatic intrusions. How many plutons form this batholith and its intrusive history remains unclear. The emplacement of the batholith began at ca. 380 Ma; the Characato suite, in the northern extreme of the body, represents a relatively young intrusive phase in its construction (ca. 360 Ma). This suite, composed mainly of two-mica monzogranites, correspons to a strongly peraluminous A-type magma (A/CNK > 1.1) with fractionated compositions (high Rb/Sr and Rb/Ba). The parental magma corresponds to a high temperature melt generated by biotite dehydration melting, which was then differentiated to form the Characato monzogranites. These monzogranites have crustal Nd and Srisotope signatures (εNdt −6.0 to −6.1 and 87Sr/86Srt 0.7074 to 0.7131) and abundant inherited zircons (ca. 90%). The inherited ages are mainly Early Cambrian, and to a lesser extent Mesoproterozoic, Neoproterozoic and Ordovician, all they recognized in the basement of the Sierras de Córdoba. The Nd-isotope composition, added to the inherited zircon ages of the Characato suite, indicate that these magmas derived from partial melting of a heterogeneous crust composed by the S-type Pampean granites and migmatites, Famatinian granitoids, and probably the low-to medium-grade metamorphic rocks of the Puncoviscan Series. The high variability and positive εHft values of the inherited Cambrian zircons found in the Characato suite could have been transferred from the Neoproterozoic grains of the Puncaviscana Series to the Early Cambrian S-type granites and migmatites during the Pampean orogeny.Item 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.Item 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.Item The relationship between large deep mafic sills, crustal contamination and the formation of Ni-(Cu) and IOCG deposits(Mineral Exploration and Research: Digging Deeper : Proceedings of the Ninth Biennial SGA Meeting, (Dublin, Ireland, 2007), 2011) Tornos Arroyo, Fernando; Carriedo, Jorge; Velasco Roldán, Francisco; Galindo Francisco, María Del Carmen; Casquet Martín, CésarThe Ossa Morena Zone (SW Iberia) hosts an unusual suite of ore deposits, including magmatic Ni-(Cu) and IOCG mineralization. These deposits are interpreted to have a relationship to a deep mafic sill intruded in the middle crust. Interaction of mafic magmas with crustal rocks produced immiscible sulphide-rich melts and water-rich melts. The latter exsolved large amounts of Fe- and CO2-rich brines that were responsible for widespread albite-actinolite alteration and IOCG mineralization.Item 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.Item Early Carboniferous sub- to mid-alkaline magmatism in the Eastern Sierras Pampeanas, NW Argentina: A record of crustal growth by the incorporation of mantle-derived material in an extensional setting(Gondwana research, 2012) Alasino, Pablo H.; Dahlquist, Juan A.; Pankhurst, R.J.; Galindo Francisco, María Del Carmen; Casquet Martín, César; Rapela, Carlos W.; Larrovere, M.A.; Fanning, C.M.A recently discovered granitic intrusion at Cerro La Gloria in western Sierra de Famatina (NW Argentina) is representative of sub- to mid-alkaline Carboniferous magmatism in the region. The main rock type consists of microcline, quartz and plagioclase, with amphibole, magnetite, ilmenite, biotite, epidote, zircon, allanite and sphene as accessory minerals. We report a U–Pb zircon SHRIMP age for the pluton of 349±3 Ma (MSWD=1.1), i.e., Tournaisian. Whole-rock chemical composition and Nd isotope analyses are compatible with an origin by melting of older mafic material in the lower crust (εNdt between −0.58 and +0.46 and TDM values of about 1.1 Ga). The pluton is intruded by penecontemporaneous to late alkaline mafic dykes that are classified as back-arc basalts. Coeval, Early Carboniferous A-type granites occur farther east in the Sierras Pampeanas, probably generated during lithospheric stretching. Overall, the Early Carboniferous granitic rocks show a west-to-east mineralogical and isotopic zonation indicating that magma genesis involved a greater contribution of juvenile material of mantle character to the west. Based on the observed patterns of geochronology, geochemistry and field relationships we suggest that A-type magma genesis in the Eastern Sierras Pampeanas was linked to an Andean-type margin where the lithospheric mantle played a role in its generation.Item Determinación de las condiciones P-T del metamorfismo Famatiniano (470 - 430 Ma) mediante pseudosección en metabasitas de la Sierra del Espinal (Sierras Pampeanas Occidentales, Argentina)(Geogaceta, 2012) Segovia Díaz, Emilio; Casquet Martín, César; Baldo, Edgardo G.; Galindo Francisco, María Del CarmenEn las sierras de Maz y El Espinal (La Rioja,Argentina) el basamento polimetamórfico (terreno Maz) registra tres eventos metamórficos: M1 y M2, grenvillianos (entre 1,05 - 1,2 Ga); M3, famatiniano (470 a 430 Ma). En el Dominio de Ramaditas de la Sierra de Espinal afloran anfibolitas granatíferas derivadas de diques basálticos emplazados en sedimentos post-grenvillianos, por lo que su metamorfismo es exclusivamente famatiniano. Ello permite resolver los efectos de M3. En estas rocas se han calculado las condiciones P-T mediante intersección de isopletas en una pseudosección en el sistema NCFMASH, obteniéndose valores de 655 ± 60 ºC y 7,2 ± 0,6 kbar. El metamorfismo fue de tipo Barroviense e implicó engrosamiento cortical significativoItem Magmatic differentiation in the calc-alkaline Khalkhab–Neshveh pluton, Central Iran(Journal of Asian earth sciences, 2011) Rezaei Kahkaei, Mehdi; Galindo Francisco, María Del Carmen; Pankhurst, R.J.; Esmaeily, DariushGeochemical and isotopic data (Sr, Nd) are presented for the Khalkhab–Neshveh pluton, an E-W elongated body of quartz monzogabbro, quartz monzodiorite, granodiorite and granite in the Urumieh– Dokhtar magmatic arc of Central Iran. The plutonic rocks are medium- to high-K, metaluminous, and I-type, with 52–71 wt.% SiO2. The geochemistry shows smooth differentiation trends in which most major elements (except Al2O3, K2O and Na2O) are negatively correlated with SiO2; K2O, Ba, Rb, Ce, Nb, and Zr are positively correlated. Na2O, Sr, Eu and Y follow curves that are not considered to represent simple mixing between mafic and felsic magmas, but reflect crystal fractionation of clinopyroxene, plagioclase and hornblende. Initial 87Sr/86Sr ratios (~0.7047) and eNdt values (~+3.0) are essentially constant, and the large volume of quartz monzogabbros compared to granites, as well as the lack of mafic enclaves in more evolved rocks, are also indicative of crystal fractionation rather than mixing of magmas from different sources. Clinopyroxene fractionation was the main control in the evolution of the magmas up to 55% SiO2; hornblende took over from 55 wt.%, resulting in decreasing Dy/Yb with increasing silica content in the most siliceous rocks. Sr concentration increases up to 55% SiO2, and then decreases together with CaO, Al2O3, Na2O. Fractionation of opaque minerals and apatite throughout the sequence, and the continuous increase in K2O and Ba vs. SiO2 reflect the absence of significant fractionation of biotite and K-feldspar. Based on geochemical and isotope data, geophysics information and field studies, it seems that suturing of the Arabia and Iran plates caused the Khalkhab and Koush nousrat faults with leftlateral strike-slip in the Urumieh–Dokhtar region, and generated a purely tensional T space at 32º to the faults which was exploited by the emplacement of Khalkhab–Neshveh pluton.