Chemical and Melting Relations of Some Calc-Alkaline Volcanic Rocks

Abstract Late Mesozoic igneous rocks are important for deciphering the Mesozoic tectonic setting of NE China. In this paper, we present whole-rock geochemical data, zircon U–Pb ages and Lu–Hf isotope data for Early Cretaceous volcanic rocks from the Tulihe area of the northern Great Xing’an Range (GXR), with the aim of evaluating the petrogenesis and genetic relationships of these rocks, inferring crust–mantle interactions and better constraining extension-related geodynamic processes in the GXR. Zircon U–Pb ages indicate that the rhyolites and trachytic volcanic rocks formed during late Early Cretaceous time (c. 130–126 Ma). Geochemically, the highly fractionated I-type rhyolites exhibit high-K calc-alkaline, metaluminous to weakly peraluminous characteristics. They are enriched in light rare earth elements (LREEs) and large-ion lithophile elements (LILEs) but depleted in high-field-strength elements (HFSEs), with their magmatic zircons ϵHf(t) values ranging from +4.1 to +9.0. These features suggest that the rhyolites were derived from the partial melting of a dominantly juvenile, K-rich basaltic lower crust. The trachytic volcanic rocks are high-K calc-alkaline series and exhibit metaluminous characteristics. They have a wide range of zircon ϵHf(t) values (−17.8 to +12.9), indicating that these trachytic volcanic rocks originated from a dominantly lithospheric-mantle source with the involvement of asthenospheric mantle materials, and subsequently underwent extensive assimilation and fractional crystallization processes. Combining our results and the spatiotemporal migration of the late Early Cretaceous magmatic events, we propose that intense Early Cretaceous crust–mantle interaction took place within the northern GXR, and possibly the whole of NE China, and that it was related to the upwelling of asthenospheric mantle induced by rollback of the Palaeo-Pacific flat-subducting slab.

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The relationship between gold mineralization, high K calc-alkaline to alkaline volcanic rocks, and A-type granite: Formation of the Daxiyingzi gold deposit in northern North China Craton

Ore Geology Reviews ◽

10.1016/j.oregeorev.2021.104383 ◽

2021 ◽

pp. 104383

Author(s):

Changfeng Liu ◽

Shouheng Zhao ◽

Wencan Liu

Keyword(s):

Gold Deposit ◽

North China Craton ◽

North China ◽

Gold Mineralization ◽

Volcanic Rocks ◽

Calc Alkaline ◽

Granite Formation ◽

High K ◽

Type Granite ◽

The Relationship

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Age, chemistry, and tectonic setting of Miramichi terrane (Early Paleozoic) volcanic rocks, eastern and east-central Maine, USA

Atlantic Geology ◽

10.4138/atlgeol.2021.012 ◽

2021 ◽

Vol 57 ◽

pp. 239-273

Author(s):

Allan Ludman ◽

Christopher McFarlane ◽

Amber T.H. Whittaker

Keyword(s):

New Brunswick ◽

Subduction Zone ◽

Tectonic Setting ◽

Volcanic Rocks ◽

Calc Alkaline ◽

East Central ◽

Arc Volcanism ◽

Middle Ordovician ◽

Volcanic Suite ◽

Back Arc

Volcanic rocks in the Miramichi inlier in Maine occur in two areas separated by the Bottle Lake plutonic complex: the Danforth segment (Stetson Mountain Formation) north of the complex and Greenfield segment to the south (Olamon Stream Formation). Both suites are dominantly pyroclastic, with abundant andesite, dacite, and rhyolite tuffs and subordinate lavas, breccias, and agglomerates. Rare basaltic tuffs and a small area of basaltic tuffs, agglomerates, and lavas are restricted to the Greenfield segment. U–Pb zircon geochronology dates Greenfield segment volcanism at ca. 469 Ma, the Floian–Dapingian boundary between the Lower and Middle Ordovician. Chemical analyses reveal a calc-alkaline suite erupted in a continental volcanic arc, either the Meductic or earliest Balmoral phase of Popelogan arc activity. The Maine Miramichi volcanic rocks are most likely correlative with the Meductic Group volcanic suite in west-central New Brunswick. Orogen-parallel lithologic and chemical variations from New Brunswick to east-central Maine may result from eruptions at different volcanic centers. The bimodal Poplar Mountain volcanic suite at the Maine–New Brunswick border is 10–20 myr younger than the Miramichi volcanic rocks and more likely an early phase of back-arc basin rifting than a late-stage Meductic phase event. Coeval calc-alkaline arc volcanism in the Miramichi, Weeksboro–Lunksoos Lake, and Munsungun Cambrian–Ordovician inliers in Maine is not consistent with tectonic models involving northwestward migration of arc volcanism. This >150 km span cannot be explained by a single east-facing subduction zone, suggesting more than one subduction zone/arc complex in the region.

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Rare earth element concentrations in Quaternary volcanic rocks of southwestern British Columbia

Canadian Journal of Earth Sciences ◽

10.1139/e84-079 ◽

1984 ◽

Vol 21 (6) ◽

pp. 731-736 ◽

Cited By ~ 4

Author(s):

Nathan L. Green ◽

Paul Henderson

Keyword(s):

British Columbia ◽

Earth Element ◽

Volcanic Rocks ◽

Crustal Contamination ◽

Lake Area ◽

Calc Alkaline ◽

Lower Light ◽

The Individual ◽

High Level ◽

Ree Patterns

A suite of hy-normative hawaiites, ne-normative mugearite, and calc-alkaline andesitic rocks from the Garibaldi Lake area exhibits fractionated, slightly concave-upward REE patterns (CeN/YbN = 4.5–15), heavy REE contents about 5–10 times the chondritic abundances, and no Eu anomalies. It is unlikely that the REE patterns provide information concerning partial melting conditions beneath southwestern British Columbia because they have probably been modified substantially by upper crustal processes including crustal contamination and (or) crystal fractionation. The REE contents of the Garibaldi Lake lavas are not incompatible with previous interpretations that (1) the hawaiites have undergone considerable fractionation of olivine, plagioclase, and clinopyroxene; and (2) the individual andesitic suites were derived from separate batches of chemically distinct magma that evolved along different high-level crystallization trends. In general, however, the andesites are characterized by lower light REE contents than the basaltic andesites. These differences in LREE abundances may reflect different amounts of LREE-rich accessory phases, such as apatite, sphene, or allanite, assimilated from the underlying quartz diorites.

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Mineralogical and Fluid Inclusions Study of Epithermal Type Veins Intruding the Volcanic Rocks of the Kornofolia Area, Evros, NE Greece.

Bulletin of the Geological Society of Greece ◽

10.12681/bgsg.20755 ◽

2019 ◽

Vol 55 (1) ◽

pp. 202

Author(s):

Foteini Aravani ◽

Lambrini Papadopoulou ◽

Vasileios Melfos ◽

Triantafillos Soldatos ◽

Triantafillia Zorba ◽

...

Keyword(s):

Crystal Structure ◽

Fluid Inclusion ◽

Hydrothermal Alteration ◽

Fluid Inclusions ◽

Volcanic Rocks ◽

The Other ◽

Calc Alkaline ◽

Ft Ir ◽

Host Rocks

The volcanic rocks of Kornofolia area, Evros, host a number of epithermal-type veins. The host rocks are Oligocene calc-alkaline andesites to rhyo-dacites. The andesites form hydrothermal breccias and show hydrothermal alteration. The veins comprise mainly silica polymorphs such as quartz, chalcedony and three types of opal (milky white, transparent and green). Amethyst also forms in veins at the same area. Apart from the silica polymorphs, the veins are accompanied by calcite and zeolites. The main aim of this study is the characterization of the silica polymorphs. Using FT-IR analyses, variations in the crystal structure of the three opals were recognized. The green opal is found to be more amorphous than the other two types. Fluid-inclusion measurements were performed in calcite and were compared with amethyst from previous studies. The Th is between 121-175 °C and the Te between -22.9 and -22.4 °C. The salinities range from 0.9 to 4.5 wt % NaCl equiv.

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Non-subduction petrological mechanisms for the growth of the neoarcheam continental crust of the Kola–Norwegian terrane, Fennoscandian shield: geological and isotope-geochemical evidence

Петрология ◽

10.31857/s0869-59032161-186 ◽

2019 ◽

Vol 27 (2) ◽

pp. 161-186

Author(s):

A. B. Vrevskii

Keyword(s):

Continental Crust ◽

Greenstone Belt ◽

Geochemical Modeling ◽

Volcanic Rocks ◽

Fennoscandian Shield ◽

Crustal Growth ◽

Calc Alkaline ◽

Geochemical Evidence

The paper reports new data on the composition and age of the Neoarchean calc-alkaline volcanic rocks of the Uraguba–Kolmozero–Voron’ya greenstone belt (UKV GB). Petrological-geochemical modeling indicates a polygenetic origin of primary melts of the basalt–andesite–dacite association and non-subduction geodynamic mechanisms for the crustal growth in the largest greenstone belt of the Kola–Norwegian Block of the Fennoscandian shield.

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Lower Palaeozoic and Precambrian igneous rocks from eastern England, and their bearing on late Ordovician closure of the Tornquist Sea: constraints from U-Pb and Nd isotopes

Geological Magazine ◽

10.1017/s0016756800023190 ◽

1993 ◽

Vol 130 (6) ◽

pp. 835-846 ◽

Cited By ~ 80

Author(s):

S. R. Noble ◽

R. D. Tucker ◽

T. C. Pharaoh

Keyword(s):

Volcanic Rocks ◽

Igneous Rocks ◽

Calc Alkaline ◽

Nd Isotopes ◽

Nd Isotope ◽

Magmatic Arc ◽

The North ◽

Basement Rocks ◽

Continental Arc ◽

Lower Palaeozoic

AbstractThe U-Pb isotope ages and Nd isotope characteristics of asuite of igneous rocks from the basement of eastern England show that Ordovician calc-alkaline igneous rocks are tectonically interleaved with late Precambrian volcanic rocks distinct from Precambrian rocks exposed in southern Britain. New U-Pb ages for the North Creake tuff (zircon, 449±13 Ma), Moorby Microgranite (zircon, 457 ± 20 Ma), and the Nuneaton lamprophyre (zircon and baddeleyite, 442 ± 3 Ma) confirm the presence ofan Ordovician magmatic arc. Tectonically interleaved Precambrian volcanic rocks within this arc are verified by new U-Pb zircon ages for tuffs at Glinton (612 ± 21 Ma) and Orton (616 ± 6 Ma). Initial εNd values for these basement rocks range from +4 to - 6, consistent with generation of both c. 615 Ma and c. 450 Ma groups of rocksin continental arc settings. The U-Pb and Sm-Nd isotope data support arguments for an Ordovician fold/thrust belt extending from England to Belgium, and that the Ordovician calc-alkaline rocks formed in response to subductionof Tornquist Sea oceanic crust beneath Avalonia.

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Chapter 3.1b Antarctic Peninsula and South Shetland Islands: petrology

Geological Society London Memoirs ◽

10.1144/m55-2018-68 ◽

2021 ◽

pp. M55-2018-68 ◽

Cited By ~ 7

Author(s):

Philip T. Leat ◽

Teal R. Riley

Keyword(s):

Antarctic Peninsula ◽

Continental Margin ◽

Volcanic Rocks ◽

Oceanic Lithosphere ◽

Contact Metamorphism ◽

South Shetland Islands ◽

Calc Alkaline ◽

The Pacific ◽

High K ◽

The Antarctic

AbstractThe Antarctic Peninsula contains a record of continental-margin volcanism extending from Jurassic to Recent times. Subduction of the Pacific oceanic lithosphere beneath the continental margin developed after Late Jurassic volcanism in Alexander Island that was related to extension of the continental margin. Mesozoic ocean-floor basalts emplaced within the Alexander Island accretionary complex have compositions derived from Pacific mantle. The Antarctic Peninsula volcanic arc was active from about Early Cretaceous times until the Early Miocene. It was affected by hydrothermal alteration, and by regional and contact metamorphism generally of zeolite to prehnite–pumpellyite facies. Distinct geochemical groups recognized within the volcanic rocks suggest varied magma generation processes related to changes in subduction dynamics. The four groups are: calc-alkaline, high-Mg andesitic, adakitic and high-Zr, the last two being described in this arc for the first time. The dominant calc-alkaline group ranges from primitive mafic magmas to rhyolite, and from low- to high-K in composition, and was generated from a mantle wedge with variable depletion. The high-Mg and adakitic rocks indicate periods of melting of the subducting slab and variable equilibration of the melts with mantle. The high-Zr group is interpreted as peralkaline and may have been related to extension of the arc.

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Magnetite–apatite intrusions and calc-alkaline magmatism, Camsell River, N.W.T.

Canadian Journal of Earth Sciences ◽

10.1139/e76-037 ◽

1976 ◽

Vol 13 (2) ◽

pp. 348-354 ◽

Cited By ~ 16

Author(s):

J. P. N. Badham ◽

R. D. Morton

Keyword(s):

Volcanic Rocks ◽

Orogenic Belt ◽

Alkaline Magmatism ◽

Calc Alkaline ◽

Immiscible Liquids ◽

Intermediate Composition ◽

Andean Type

The Camsell River area comprises a roof pendant of volcanic rocks within an Aphebian (~1800 m.y.) orogenic belt. Magnetite–apatite intrusions and related bodies are common and are closely associated with plutons of intermediate composition. The magnetitic intrusions are interpreted as immiscible liquids that separated from a magma of intermediate composition. The immiscible fractions were predominantly crystalline when they reached their present higher levels, and final emplacement was facilitated by volatile-streaming and fluidization. Their presence in the orogenic belt is taken as further support for the hypothesis that the orogen was of Andean type.

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