Sr, Nd and Pb isotope and geochemical data from the Quaternary Nevado de Toluca volcano, a source of recent adakitic magmatism, and the Tenango Volcanic Field, Mexico

2004 ◽  
Vol 138 (1-2) ◽  
pp. 77-110 ◽  
Author(s):  
Raymundo G. Martínez-Serrano ◽  
Peter Schaaf ◽  
Gabriela Solís-Pichardo ◽  
Ma. del Sol Hernández-Bernal ◽  
Teodoro Hernández-Treviño ◽  
...  
Keyword(s):  
Volcanic Field ◽  
Geochemical Data ◽  
Pb Isotope ◽  
Nevado De Toluca

scholarly journals Spatial Visualization of Geochemical Data: Application to the Chichinautzin Volcanic Field, Mexico

2020 ◽  
Author(s):  
Philippe Robidoux ◽  
Julie Roberge ◽  
César Adams
Keyword(s):  
Spatial Visualization ◽  
Volcanic Field ◽  
Geological Mapping ◽  
Geochemical Data ◽  
Geochemical Mapping ◽  
Mapping Model ◽  
Data Application ◽  
Spatial Analyst ◽  
Geochemical Markers ◽  
Nevado De Toluca

The presence of spatial magma heterogeneities in volcanic monogenetic fields is a major observation discussed as well synthesized for worldwide volcanic fields. Magma heterogeneities still have not been visualized in the form of detailed spatial analyst tools, which could further help structuring works of geological mapping, volcanic hazard, and geoheritage evaluations. Here we synthetized 32 published datasets with a novel geochemical mapping model inspired by sub-disciplines of geomatic in one of the most documented monogenetic fields on earth: the Chichinautzin Volcanic Field (CVF) in Mexico. The volcanic units from CVF are covering the 2500 km2 area, and its neighbor stratovolcanoes are bordering the limit of most volcanic centers (Popocatepetl, Iztaccihuatl, and Nevado de Toluca). The results illustrate polygons and point map symbols from geochemical markers such as Alkalis vs SiO2, Sr/Y, and Ba/Nb. The geochemical heterogeneity of the CVF monogenetic bodies decreases as it approaches the Popocatepetl-Iztaccihuatl stratovolcanoes. This alignment is not observed in the occidental CVF portion near the flank of Nevado de Toluca, but geochemical anomalies associated to markers of continental crust interaction such as Sr/Y follow elongated patterns that are not strictly following structural lines and faults mapped on surface.

scholarly journals Supplemental Material: Interplay of Cretaceous transpressional deformation and continental arc magmatism in a long-lived crustal boundary, central Fiordland, New Zealand

2020 ◽  
Author(s):  
H.J. Blatchford ◽  
et al.
Keyword(s):  
New Zealand ◽  
Cross Sections ◽  
Geochemical Data ◽  
Arc Magmatism ◽  
Sample Collection ◽  
Pb Isotope ◽  
Continental Arc ◽  
Geologic Map ◽  
Backscattered Electron ◽  
Continental Arc Magmatism

Analytical methods used are described in Supplemental Text. Sample collection locations shown in Figure 3 are detailed in Table S1. Isotopic and geochemical data are presented in Tables S2–S4. U-Pb isotope data and geochemistry data for the sample are presented in Tables S5 and S6, respectively. A series of cross sections and a geologic map of the study area including field stations and associated structural measurements are presented in Figure S1. Cathodoluminescence images of zircon grains are shown in Figures S2 and S3. Backscattered electron images of analyzed titanite grains are presented in Figure S4.<br>

scholarly journals Trace-Element and Pb Isotope Evidence on Extracting Sulfides from Potassic Melts beneath Longmenshan and Molabushan Volcanoes, Wudalianchi, Northeast China

Minerals ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 319 ◽  
Author(s):  
Sergei Rasskazov ◽  
Yi-Min Sun ◽  
Irina Chuvashova ◽  
Tatyana Yasnygina ◽  
Chen Yang ◽  
...  
Keyword(s):  
Trace Element ◽  
Volcanic Rocks ◽  
Volcanic Field ◽  
Lava Flows ◽  
Pb Isotope ◽  
Linear Pattern ◽  
Wide Range ◽  
Mantle Sources ◽  
Isotope Evidence ◽  
Isotope Study

In the Wudalianchi volcanic field, eruptions started with low-Mg potassic lava flows 2.5–2.0 Ma ago and later changed to both low- and moderate-Mg potassic compositions. Volcanic rocks from the Molabushan and Longmenshan volcanoes record an unusually wide range of Pb abundances (from 3.7 ppm to 21 ppm relative to predominant range of 10–15 ppm). To determine the cause of these, we performed a comparative trace-element and Pb isotope study of rocks from these volcanoes and older lava flows. On a uranogenic lead diagram, older low-Mg lavas from lithospheric mantle sources plot on a secondary isochron with a slope corresponding to an age of 1.88 Ga. This contrasts with moderate-Mg volcanic rocks from the Molabushan cone, interpreted to have been derived from a recent convective mantle source, which define a flat linear pattern. Low-Mg rocks from the Molabushan flow have lead isotopic compositions that indicate mixed Gelaqiu and Molabu sources. Relative to rocks from the Molabushan cone, moderate-Mg lavas and slags from the East Longmenshan volcano have modified compositions characterized by Pb, S, and Ni abundances, Ni/Co, Ni/MgO ratios as well as 206Pb/204Pb, 207Pb/204Pb, 208Pb/204Pb, Ce/Pb, Th/Pb, and U/Pb ratios. We infer that the older Wudalianchi magmas were likely derived from a Paleoproterozoic lithospheric fragment, related to the evolved primordial mantle, and that later magmas were generated in the convecting mantle. These were influenced by segregation of small amounts of sulfides.

scholarly journals Archean Rocks of the Diorite Window Block in the Southern Framing of the Monchegorsk (2.5 Ga) Layered Mafic-Ultramafic Complex (Kola Peninsula, Russia)

Minerals ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 848
Author(s):  
Pavel Pripachkin ◽  
Tatiana Rundkvist ◽  
Nikolay Groshev ◽  
Aiya Bazai ◽  
Pavel Serov
Keyword(s):  
Kola Peninsula ◽  
Geochemical Data ◽  
Pb Isotope ◽  
Garnet Porphyroblasts ◽  
Isotope Data ◽  
Ultramafic Complex ◽  
Archean Basement ◽  
Monchegorsk Complex

The intermediate rocks classified as diorite-gneisses occur within the southern part of the Monchegorsk (2.5 Ga) layered mafic-ultramafic complex (Kola Peninsula, Russia). These diorite-gneisses belong to a block historically known as the diorite window (DW) block. The same rocks occur in a framing of the Monchegorsk complex. The DW block is predominantly composed of diorite-gneisses and, to a lesser degree, of amphibolites. Multi-ordinal banding, complex folding, boudinage and metamorphic transformations, garnet porphyroblasts, and tourmaline veinlets are typical of the diorite-gneisses. In accordance with the U-Pb isotope data, the age of the diorite-gneisses in the DW block is 2736.0 ± 4.6 Ma. The Sm-Nd mineral (garnet, biotite, and tourmaline) isochron for the DW rocks has yielded an age of 1806 ± 23 Ma (related to the processes of the Svecofennian orogeny). The DW diorite-gneisses are compared with the metadiorites of the Gabbro-10 massif. The latter is a part of the Monchegorsk complex, with U-Pb crystallization age of 2498 ± 6 Ma. On the basis of geological and isotope-geochemical data, it is shown that the DW rocks belong to the Archean basement while the Gabbro-10 metadiorites probably represent one of the late-magmatic phases of the Monchegorsk complex.

scholarly journals Degassing Rhythms and Fluctuations of Geogenic Gases in A Red Wood-Ant Nest and in Soil in The Neuwied Basin (East Eifel Volcanic Field, Germany)

Insects ◽  
2018 ◽  
Vol 9 (4) ◽  
pp. 135 ◽  
Author(s):  
Gabriele M. Berberich ◽  
Martin B. Berberich ◽  
Aaron M. Ellison ◽  
Christian Wöhler
Keyword(s):  
Coupled System ◽  
Ambient Air ◽  
Biological Indicators ◽  
Volcanic Field ◽  
Geochemical Data ◽  
Geochemical Tracers ◽  
Formica Polyctena ◽  
Infradian Rhythms ◽  
Ant Nest ◽  
Buried Fault

Geochemical tracers of crustal fluids (CO2, He, Rn) provide a useful tool for the identification of buried fault structures. We acquired geochemical data during 7-months of continual sampling to identify causal processes underlying correlations between ambient air and degassing patterns of three gases (CO2, He, Rn) in a nest of red wood ants (Formica polyctena; “RWA”) and the soil at Goloring in the Neuwied Basin, a part of the East Eifel Volcanic Field (EEVF). We explored whether temporal relations and degassing rhythms in soil and nest gas concentrations could be indicators of hidden faults through which the gases migrate to the surface from depth. In nest gas, the coupled system of CO2-He and He concentrations exceeding atmospheric standards 2-3 fold suggested that RWA nests may be biological indicators of hidden degassing faults and fractures at small scales. Equivalently periodic degassing infradian rhythms in the RWA nest, soil, and three nearby minerals springs suggested NW-SE and NE-SW tectonic linkages. Because volcanic activity in the EEVF is dormant, more detailed information on the EEVF’s tectonic, magmatic, and degassing systems and its active tectonic fault zones are needed. Such data could provide additional insights into earthquake processes that are related to magmatic processes at the lower crust.

scholarly journals Supplemental Material: Interplay of Cretaceous transpressional deformation and continental arc magmatism in a long-lived crustal boundary, central Fiordland, New Zealand

2020 ◽  
Author(s):  
H.J. Blatchford ◽  
et al.
Keyword(s):  
New Zealand ◽  
Cross Sections ◽  
Geochemical Data ◽  
Arc Magmatism ◽  
Sample Collection ◽  
Pb Isotope ◽  
Continental Arc ◽  
Geologic Map ◽  
Backscattered Electron ◽  
Continental Arc Magmatism

Analytical methods used are described in Supplemental Text. Sample collection locations shown in Figure 3 are detailed in Table S1. Isotopic and geochemical data are presented in Tables S2–S4. U-Pb isotope data and geochemistry data for the sample are presented in Tables S5 and S6, respectively. A series of cross sections and a geologic map of the study area including field stations and associated structural measurements are presented in Figure S1. Cathodoluminescence images of zircon grains are shown in Figures S2 and S3. Backscattered electron images of analyzed titanite grains are presented in Figure S4.<br>

Crustal melting and granite genesis during the Himalayan collision orogenesis

1988 ◽  
Vol 79 (2-3) ◽  
pp. 183-195 ◽  
Author(s):  
Christian France-Lanord ◽  
Patrick Le Fort
Keyword(s):  
Partial Melting ◽  
Melting Zone ◽  
Geochemical Data ◽  
Magmatic Differentiation ◽  
Sediment Composition ◽  
Pb Isotope ◽  
Central Nepal ◽  
Inverted Metamorphism ◽  
Isotope Studies ◽  
O Isotope

ABSTRACTThis paper reviews the petrogenesis of Himalayan leucogranites (HHγ) on the basis of field, petrological and geochemical data collected over the last fifteen years. HHγ are intruded at the top of the 2 to 8km-thick High Himalayan Crystallines (HHC). These are metamorphosed (Ky to Sill) and present much evidence of partial melting. During the MCT thrusting, the already metamorphosed HHC were thrust on top of the weakly metamorphosed Midland Formations, inducing the main phase of Himalayan metamorphism. The genesis of HHγ and North Himalaya leucogranites (NHγ) associates thrusting along the MCT, propagation of inverted metamorphism, liberation of large quantities of fluid in the Midlands, and partial melting of the HHC.The restricted compositions of the granites are close to minimum melt compositions; variations in the alkali ratio probably relate to the variable amount of B, F and H2O. The HHγ were issued from the migmatitic zone around 700°C and 800 MPa., and still emplaced some 10 to 15 km below the surface. This syn- to late-tectonic emplacement of the leucogranites lasted for more than 10 Ma according to isotopic ages (25 to 14 Ma).O, Rb–Sr, Nd–Sm and Pb isotope studies corroborate the unambiguous filiation between the HHC and the leucogranites in central Nepal. They also imply that the plutons are generated as numerous poorly mixed batches of magma produced preferentially in specific zones of the source rock. δD values may be explained by infiltration of water from the Midlands in the melting zone, and/or by water degassing during crystallisation. The positive covariations between Sr-, Nd- and O-isotope ratios relate to the variations in the original sediment composition of the source gneisses. Whereas trace element characteristics often date back to the anatectic process, limited magmatic differentiation is recorded by the biotite. These granites are typical crustal products, keeping track of some of the pre-Himalayan evolution together with that of their own origin.

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