Thermal maturation of a complete magmatic plumbing system at the Sierra de Velasco, Northwestern Argentina

2020 ◽  
pp. 1-18
Author(s):  
Marcos Macchioli Grande ◽  
Pablo Alasino ◽  
Juan Dahlquist ◽  
Matías Morales Cámera ◽  
Carmen Galindo ◽  
...  
Keyword(s):  
Structural Model ◽  
Intrusive Complex ◽  
Zircon Age ◽  
Crustal Component ◽  
Thermal Maturation ◽  
Plumbing Systems ◽  
Magmatic Plumbing System ◽  
Higher Temperature ◽  
Lower Crustal ◽  
Integrated Study

Abstract The formation of magmatic plumbing systems in the crust involves mass and heat transfer from deep to shallow levels. This process modifies the local geotherm and increases the thermal maturation of the crust, affecting the rheological state of the host rock and the composition of magma. Here, we report a petrological, geochemical, isotopic and geochronological integrated study of the Huaco (~354 Ma) and Sanagasta (~353 Ma, from a new U–Pb zircon age) units from the Carboniferous (Lower Mississippian) Huaco Intrusive Complex, NW Argentina. Similar values of ϵNd t and δ18O, of −3.2 ± 0.7 and +11.2‰ ± 0.3‰ (V-SMOW), respectively, for both units indicate that they shared the same source, as a result of mixing and later homogenization of a crustal component at the Late Devonian (~378 to 366 Ma), with metasomatized mantle-derived melts. Slightly higher contents of TiO2, FeO, MgO, CaO and rare earth elements for the Sanagasta unit in comparison with the Huaco unit suggest an increase in the degree of partial melting, which may have been caused by a higher temperature at the lower crust. In addition, the previous structural model of the Huaco Intrusive Complex points to an increase in thermal maturation in the upper crust, which drives a change in the emplacement style from tabular subhorizontal (Huaco) to vertically elongated (Sanagasta) bodies. Therefore, the evolution of the intrusive complex may reflect a generalized thermal maturation of the complete magmatic column, at both upper and lower crustal levels.

Short-lived mafic magmatism at 560–570 Ma in the northern Norwegian Caledonides: U–Pb zircon ages from the Seiland Igneous Province

2006 ◽  
Vol 143 (6) ◽  
pp. 887-903 ◽  
Author(s):  
R. J. ROBERTS ◽  
F. CORFU ◽  
T. H. TORSVIK ◽  
L. D. ASHWAL ◽  
D. M. RAMSAY
Keyword(s):  
Structural Model ◽  
Mafic Magma ◽  
Zircon Age ◽  
Mafic Intrusions ◽  
Short Time Span ◽  
Extensional Tectonic ◽  
Nappe Complex ◽  
Igneous Province ◽  
Granitic Intrusions ◽  
Short Time

The Seiland Igneous Province (SIP) of northern Norway comprises a suite of mainly gabbroic plutons, with subordinate ultramafic, syenitic and felsic intrusions. Several intrusions from the Seiland Igneous Province have been dated by ID-TIMS U–Pb zircon and monazite analyses. The Hasvik Gabbro on the island of Sørøy, previously assigned an age of 700±33 Ma by Sm–Nd, yields a U–Pb zircon age of 562±6 Ma, within error of the Storelv Gabbro (569±5 Ma) and a diorite associated with the Breivikbotn Gabbro (571±4 Ma). Various intrusions on the Øksfjord peninsula give nearly identical ages of 565±9 Ma (gabbro), 566±4 Ma (monzonite), 565±5 Ma (monzodiorite), 570±9 Ma (norite), and 566±1 Ma (orthopyroxenite). These ages overlap with those from Sørøy, and define a single and short-lived period of gabbroic (to felsic) magmatism for the region between 570 and 560 Ma, pre-dating a subordinate episode of alkalic magmatism at 530–520 Ma. The U–Pb ages contradict the previous geochronological interpretation for the Finnmark area, which implied a period of 250 m.y. for the emplacement of the SIP intrusions. The new age data also clearly distinguish the Seiland intrusions, emplaced into the Sørøy Group metasediments of the Kalak Nappe Complex, from several older granitic intrusions (c. 850 to 600 Ma) that cut the Sørøy Group farther east and south. The coincident ages of the different Seiland intrusive bodies also contradict the previous structural model for the area, which posits that the different gabbro bodies were emplaced at intervals, with compressional deformation affecting the gabbros between periods of intrusion. The short time span between the main plutonic phases strongly suggests that the mechanism for the emplacement of mafic magma operated in a single, probably extensional, tectonic regime. The mafic intrusions were later deformed and metamorphosed to at least amphibolite facies, most likely by the Scandian (420 Ma) phase of the Caledonian Orogeny.

scholarly journals Anatomy of the magmatic plumbing system of Los Humeros Caldera (Mexico): implications for geothermal systems

2019 ◽  
Author(s):  
Federico Lucci ◽  
Gerardo Carrasco-Núñez ◽  
Federico Rossetti ◽  
Thomas Theye ◽  
John C. White ◽  
...  
Keyword(s):  
Volcanic Belt ◽  
Mineral Chemistry ◽  
Volcanic Complex ◽  
Geothermal Systems ◽  
Plumbing System ◽  
Geothermal Exploration ◽  
Geothermal Fields ◽  
Mexican Volcanic Belt ◽  
Plumbing Systems ◽  
Magmatic Plumbing System

Abstract. Understanding the anatomy of magma plumbing systems of active volcanoes is essential not only for unraveling magma dynamics and eruptive behaviors, but also to define the geometry, depth and temperature of the heat sources for geothermal exploration. The Pleistocene-Holocene Los Humeros volcanic complex is part of the Eastern Trans-Mexican Volcanic Belt (Central Mexico) and it represents one of the most important exploited geothermal fields in Mexico with ca. 90 MW of produced electricity. A field-based petrologic and thermobarometric study of lavas erupted during the Holocene (post-Caldera stage) has been performed with the aim to decipher the anatomy of the magmatic plumbing system existing beneath the caldera. New petrographical, whole rock major element data and mineral chemistry were integrated within a suite of inverse thermobarometric models. Compared with previous studies where a single voluminous melt-controlled magma chamber (or "Standard Model") at shallow depths was proposed, our results support a more complex and realistic scenario characterized by a heterogeneous multilayered system comprising a deep (ca. 30 km) basaltic reservoir feeding progressively shallower and smaller distinct stagnation layers, pockets and batches up to very shallow conditions (1 kbar, ca. 3 km). Evolution of melts in the feeding system is mainly controlled by differentiation processes via fractional crystallization, as recorded by polybaric crystallization of clinopyroxenes and orthopyroxenes. Moreover, this study attempts to emphasize the importance to integrate field-petrography, texture observations and mineral chemistry of primary minerals to unravel the pre-eruptive dynamics and therefore the anatomy of the plumbing system beneath an active volcanic complex, which notwithstanding the numerous existing works is still far to be well understood. A better knowledge of the heat source feeding geothermal systems is very important to improve geothermal exploration strategies.

Recognition of a 1.85 Ga oceanic rifting environment in southeastern Sweden

2020 ◽  
Author(s):  
Evgenia Salin ◽  
Krister Sundblad ◽  
Yann Lahaye ◽  
Jeremy Woodard
Keyword(s):  
Volcanic Rocks ◽  
Ductile Deformation ◽  
Coarse Grained ◽  
Southern Sweden ◽  
Zircon Age ◽  
Crustal Component ◽  
Southwestern Margin ◽  
Felsic Volcanic ◽  
Back Arc ◽  
Geochronological Evidence

<p>The Fröderyd Group constitutes a deformed volcanic sequence, which together with the 1834 Ma Bäckaby tonalites occurs as a xenolith, within the 1793-1769 Ma TIB 1b unit of the Transscandinavian Igneous Belt (TIB) in southern Sweden. The Bäckaby tonalites, together with coarse-grained clastic metasedimentary sequences of the Vetlanda Group, belong to the Oskarshamn-Jönköping Belt (OJB; Mansfeld et al., 1996). In turn, the Fröderyd Group was considered to be an older, probably Svecofennian, unit by Sundblad et al. (1997).</p><p>The Fröderyd Group is composed of ca. 80% mafic and ca. 20% felsic volcanic rocks, with subordinate carbonate units. Mafic rocks are represented by tholeiitic basalts and spilitized pillow lavas with MORB affinity.</p><p>In this study, a sample from a metamorphosed rhyolite, belonging to the Fröderyd Group, was dated at 1849.5±9.8 Ga U-Pb zircon age (LA-ICPMS). This age is significantly younger than the Svecofennian crust, which was formed from 1.92 to 1.88 Ga. Instead, it is coeval with the oldest TIB granitoid generation (TIB 0), which intruded into the southwestern margin of the Svecofennian Domain, but the Fröderyd Group is still the oldest crustal component southwest of the Svecofennian Domain.</p><p>Geochronological, petrographical studies and field observations have shown that the southern margin of the Svecofennian Domain was affected by ductile deformation shortly after the intrusion of the 1.85 Ga TIB granites (Stephens and Andersson, 2005). This took place during an intra- or back-arc rifting above a subduction boundary in a retreating mode and caused formation of augen gneisses and emplacement of 1847 Ga dykes into the TIB 0 granitoids. Rifting was followed by a collision of the rifted slab with the Svecofennian crust which is evidenced from emplacement of pegmatitic leucosomes during 1.83-1.82 Ga into the 1.85 Ga orthogneisses.</p><p>It is interpreted, that the Fröderyd Group was formed within an oceanic rifting environment, collided with the rifted Svecofennian slab and later amalgamated onto the Svecofennian Domain. The proposed geological evolution includes two deformation events during the period of ca. 1.85-1.82 Ga, which is in accordance with Röshoff (1975). Furthermore, it is evident that the Fröderyd Group was formed as a separate unit outside the Svecofennian Domain, although they have a common geological history.      </p><p>References</p><p>Mansfeld, J., 1996. Geological, geochemical and geochronological evidence for a new Palaeoproterozoic terrane in southeastern Sweden. Precambrian Res. 77, 91–103.</p><p>Röshoff, K., 1975. Some aspects of the Precambrian in south-eastern Sweden in the light of a detailed geological study of the Lake Nömmen area. Geologiska Föreningens i Stockholm Förhandlingar 97, 368–378.</p><p>Stephens, M.B. and Andersson, J., 2015. Migmatization related to mafic underplating and intra- or back-arc spreading above a subduction boundary in a 2.0–1.8 Ga accretionary orogen. Sweden. Precambrian Res. 264, 235–257.</p><p>Sundblad, K., Mansfeld, J. and Särkinen, M., 1997. Palaeoproterozoic rifting and formation of sulphide deposits along the southwestern margin of the Svecofennian Domain, southern Sweden. Precambrian Res. 182, 1–12.</p>

Thermochemical modelling of zircon age distributions from Nevado de Toluca volcano, Trans Mexican Volcanic Belt

2020 ◽  
Author(s):  
Gregor Weber ◽  
Luca Caricchi ◽  
Axel Schmitt ◽  
José Luis Arce
Keyword(s):  
Large Fraction ◽  
Temporal Trends ◽  
Volcanic Belt ◽  
Thermal Modelling ◽  
Zircon Geochronology ◽  
Zircon Age ◽  
Zircon Crystallization ◽  
Plumbing Systems ◽  
Nevado De Toluca ◽  
Rate Of Accumulation

<p>Understanding the assembly of eruptible magma in volcanic plumbing systems through time is key to the evaluation of hazard scenarios at potentially active volcanoes. In this respect, zircon geochronology provides a temporally resolvable record of the presence of magma. However, which specific processes and associated timescales are captured by zircon age distributions is not well constrained. Here we use zircon geochronology and geochemistry and thermal modelling of pulsed magma injection in the Earth crust to quantitatively invert zircon ages and recalculate magma fluxes and the rate of accumulation of eruptible magma in time. Zircon crystals have been analyzed from 4 late Pleistocene eruptions of Nevado de Toluca, a long-lived currently dormant dacitic stratovolcano in Central Mexico. <sup>238</sup>U-<sup>230</sup>Th and <sup>238</sup>U-<sup>206</sup>Pb age distributions show a protracted zircon crystallization history of ~900 ka in the magmatic plumbing system, a large fraction of the 1500 ka record of volcanic activity at the surface for this volcano. The 4 studied eruptions show similar broad age spectra, which are overlapping with each other and comparable peak zircon crystallization ages between 150 and 250 ka. Our dataset suggests that interstitial melt extraction (including zircon crystals) from highly crystallized resident magma and mixing thereof with fresh recharge magma surges is very efficient beneath Nevado de Toluca. Zircon trace element data, together with the geochronology show that the observed temporal trends in zircon geochemistry are consistent with tracking long-term assembly processes beneath the volcano operating over more than 1 million years. The combination of these results and thermal modelling allow us to quantify the rate of magma input, intrusive/extrusive ratio and the rate of accumulation of eruptible magma at Nevado de Toluca, which is essential to estimate the maximum potential size of the next eruption from this system.</p>

Geology, geochronology, and geochemistry of basaltic flows of the Cat Hills, Cat Mesa, Wind Mesa, Cerro Verde, and Mesita Negra, central New Mexico

2006 ◽  
Vol 43 (9) ◽  
pp. 1251-1268 ◽  
Author(s):  
Florian Maldonado ◽  
James R Budahn ◽  
Lisa Peters ◽  
Daniel M Unruh
Keyword(s):  
New Mexico ◽  
Trace Element Composition ◽  
Rio Grande Rift ◽  
Magma Source ◽  
Temporal Shift ◽  
Crustal Component ◽  
Isotopic Compositions ◽  
Source Regions ◽  
Enriched Mantle ◽  
Lower Crustal

The geochronology, geochemistry, and isotopic compositions of basaltic flows erupted from the Cat Hills, Cat Mesa, Wind Mesa, Cerro Verde, and Mesita Negra volcanic centres in central New Mexico indicate that each of these lavas had unique origins and that the predominant mantle involved in their production was an ocean-island basalt type. The basalts from Cat Hills (0.11 Ma) and Cat Mesa (3.0 Ma) are similar in major and trace element composition, but differences in MgO contents and Pb isotopic values are attributed to a small involvement of a lower crustal component in the genesis of the Cat Mesa rocks. The Cerro Verde rock is comparable in age (0.32 Ma) to the Cat Hills lavas, but it is more radiogenic in Sr and Nd, has higher MgO contents, and has a lower La/Yb ratio. This composition is explained by the melting of an enriched mantle source, but the involvement of another crustal component cannot be disregarded. The Wind Mesa rock is characterized by similar age (4.01 Ma) and MgO contents, but it has enriched rare-earth element contents compared with the Cat Mesa samples. These are attributed to a difference in the degree of partial melting of the Cat Mesa source. The Mesita Negra rock (8.11 Ma) has distinctive geochemical and isotopic compositions that suggest a different enriched mantle and that large amounts of a crustal component were involved in generating this magma. These data imply a temporal shift in magma source regions and crustal involvement, and have been previously proposed for Rio Grande rift lavas.

A Rb–Sr isotopic study of the Archean rocks of the eastern Lac Seul region, English River subprovince, northwestern Ontario

1980 ◽  
Vol 17 (5) ◽  
pp. 569-576 ◽  
Author(s):  
Joseph L. Wooden ◽  
Alan M. Goodwin
Keyword(s):  
Source Region ◽  
Granitic Rocks ◽  
Isotopic Study ◽  
Zircon Age ◽  
Crustal Rocks ◽  
Northwestern Ontario ◽  
Plutonic Complex ◽  
History Of ◽  
Lower Crustal ◽  
Good Agreement

Rb–Sr whole-rock data for the gneissic and granitic rocks of the eastern Lac Seul region, when combined with the U–Pb zircon dating of Krogh, document a history of multiple intrusion for the area. The oldest rocks are the Sen Bay plutonic complex gneisses which have complex Rb–Sr systematics. Interpretation of the Rb–Sr data yields model ages of 3000–3100 Ma which are in good agreement with a zircon age of 3040 Ma. The next oldest rocks are trondhjemitic–granodioritic gneisses with a Rb–Sr age of 2780 ± 90 Ma. The initial Sr ratio (I) of 0.7009 ± 4 for these rocks suggests that this age approximates the time of intrusion and that the magma was derived from lower crustal rocks with a very short residence lime in the crust. Following a period of deformation and metamorphism, granodioritic to granitic dikes, sills, and small plutons were intruded between 2660 and 2560 Ma ago. I values for these racks range from 0.7019–0.7027. If the I values of these rocks represent the source region for the granitic magmas, then one explanation for the I values would be that the magmas were derived from a source region of mixed lithology and age. The Sen Bay plutonic complex is considered to represent an earlier cycle of crustal formation which is distinct from a later 2800–2550 Ma old cycle which dominates much of the Superior Province.

U-PB ZIRCON AGE OF DYKES IN THE ROOF OF THE BLACK PEAK INTRUSIVE COMPLEX, NORTH CASCADES

2017 ◽  
Author(s):  
Robert Cruze ◽  
◽  
Adam J.R. Kent ◽  
Robert B. Miller ◽  
Erin Shea
Keyword(s):  
Intrusive Complex ◽  
North Cascades ◽  
Zircon Age

A geochemical and Sr-Nd-O isotopic study of the Proterozoic Eriksfjord Basalts, Gardar Province, South Greenland: Reconstruction of an OIB signature in crustally contaminated rift-related basalts

2003 ◽  
Vol 67 (5) ◽  
pp. 831-853 ◽  
Author(s):  
R. Halama ◽  
T. Wenzel ◽  
B. G. J. Upton ◽  
W. Siebel ◽  
G. Markl
Keyword(s):  
Trace Element ◽  
Granulite Facies ◽  
Alkaline Basalt ◽  
Isotopic Study ◽  
Nd Isotope ◽  
Crustal Component ◽  
Isotope Data ◽  
Enriched Mantle ◽  
Mantle Sources ◽  
Lower Crustal

AbstractBasalts from the volcano-sedimentary Eriksfjord Formation (Gardar Province, South Greenland) were erupted at around 1.2 Ga into rift-related graben structures. The basalts have compositions transitional between tholeiite and alkaline basalt with MgO contents <7 wt.% and they display LREE-enrichment relative to a chondritic source. Most of the trace element and REE characteristics are similar to those of basalts derived from OIB-like mantle sources. Initial 87Sr/86Sr ratios of clinopyroxene separates range from 0.70278 to 0.70383 and initial ϵNd values vary from –3.2 to +2.1. The most unradiogenic samples overlap with the field defined by carbonatites of similar age and can be explained by mixing of isotopically depleted and enriched mantle components. Using AFC modelling equations, the Sr-Nd isotope data of the more radiogenic basalts can successfully be modelled by addition of <5% lower crustal granulite-facies gneisses as contaminants. δ18Ov-smow values of separated clinopyroxene range from +5.2 to +6.0% and fall within the range of typical mantle-derived rocks. However, up to 10% mixing with an average lower crustal component are permitted by the data.

XIII.—Granites and Associated Rocks of the Eastern Part of the Western Redhills Complex, Isle of Skye

1966 ◽  
Vol 66 (13) ◽  
pp. 307-343 ◽  
Author(s):  
J. D. Bell
Keyword(s):  
Chemical Properties ◽  
Layered Intrusion ◽  
Intrusive Complex ◽  
Thermal Requirements ◽  
Higher Temperature ◽  
Basement Gneiss ◽  
High Level ◽  
Isle Of Skye ◽  
Ring Dyke ◽  
And Chemical Properties

SynopsisThe country lying between the head of Loch Ainort and the northern end of the Blaven Range in central Skye forms part of a Tertiary igneous complex. Country rocks in the area are Jurassic sediments. The earliest igneous rocks are basalt lavas which show the effects of thermal metamorphism by a later intrusion of eucrite and gabbro. This latter, which is part of the Blaven mass, has features of a layered intrusion such as igneous lamination, repetition of layers rich in certain minerals and comparable textures. It may be correlated with zones of the Cuillin layered intrusion. The eucrites are cut by a cone sheet swarm. Adjacent to the eucrite is a vent breccia which contains eucrite blocks, is not cut by cone sheets and is, therefore, of later age than the eucrite. The major part of the area under discussion is formed from four granitic ring dykes and a hybrid suite with ring dyke form, all of which belong to the Western Redhills intrusive complex; in addition, part of a fifth granitic ring dyke, which probably belongs to the Eastern Redhills intrusive complex is included in the area. The granites are mainly fayalite-hedenbergite types with a variety of phenocrysts of felspar and features characteristic of high level intrusions such as granophyric texture and varying optical and chemical properties of the felspar indicating higher temperature modifications. Three new chemical analyses of the granites and one of ferrohedenbergitic pyroxene are presented. The granites may be regarded as partial remelts of the underlying basement gneiss and a simple investigation of thermal requirements indicates that the heat necessary for the partial melting could be provided by a mass of basic rock presumed from geophysical evidence to underlie the complex. Various acid and basic minor intrusions in the area are also described.

U–Pb zircon ages for rocks from the Island Lake greenstone belt, Manitoba

1986 ◽  
Vol 23 (1) ◽  
pp. 92-101 ◽  
Author(s):  
A. Turek ◽  
T. M. Carson ◽  
Patrick E. Smith ◽  
W. R. Van Schmus ◽  
W. Weber
Keyword(s):  
Greenstone Belt ◽  
Quartz Diorite ◽  
Superior Province ◽  
Intrusive Complex ◽  
Quartz Porphyry ◽  
Zircon Age ◽  
Metasedimentary Rocks ◽  
Intrusive Rocks ◽  
Granitoid Rocks

The Archean Hayes River Group of the Island Lake greenstone belt (Superior Province, Sachigo Subprovince) comprises mafic to felsic metavolcanics, subvolcanics, and associated metasedimentary rocks. The Hayes River Group is intruded by granitoid rocks belonging to the early intrusive complex. One such pluton, the Bella Lake tonalite, is intrusive into the metabasalt of the Hayes River Group and has a U–Pb zircon age of 2886 ± 15 Ma. Similar intrusives of this complex, either internal or marginal to the greenstone belt, yield zircon ages of 2801 ± 8 Ma (Pipe Point tonalit) and 2768 ± 22 Ma (Linklater Island prophyry). This suggests that the early intrusive complex was emplaced over an ~ 120 Ma long interval by at least three separate intrusive episodes.Subsequent to the emplacement of the early intrusive complex, the isoclinally folded Hayes River Group and the early intrusive complex were uplifted, eroded, and followed by the unconformable deposition of the Island Lake Group, comprising fluvial to marine metasedimentary rocks. The stratigraphically lower part of the Island Lake Group is bracketed by the 2768 ± 22 Ma age of the Linklater Island porphyry and the 2729 ± 3 Ma age obtained for the late tectonic suite—the Pipe Point quartz diorite and feldspar porphyry. A feldspar quartz porphyry belonging to the post-tectonic intrusive rocks intrudes higher stratigraphic levels and has been dated at 2699 ± 4 Ma (Horseshoe Island quartz feldspar porphyry).

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