Hyperfunc: BASIC program to calculate hyperbolic magma-mixing curves for geochemical data

1987 ◽  
Vol 13 (4) ◽  
pp. 421-431 ◽  
Author(s):  
Gérard Woussen ◽  
Denis Côté
Keyword(s):  
Magma Mixing ◽  
Basic Program ◽  
Geochemical Data ◽  
Mixing Curves

Geochronology and geochemistry of igneous rocks in the southeastern Lesser Xing’an Range, northeastern China: petrogenesis and implications for the early Mesozoic tectonic evolution

2020 ◽  
Vol 57 (4) ◽  
pp. 506-523
Author(s):  
Jin-hua Qin ◽  
Cui Liu ◽  
Jin-fu Deng
Keyword(s):  
Field Strength ◽  
Inductively Coupled Plasma ◽  
High Field ◽  
Magma Mixing ◽  
Tectonic Setting ◽  
Alkali Feldspar ◽  
Igneous Rocks ◽  
Geochemical Data ◽  
High Field Strength ◽  
Alkaline Granite

We present systematic U–Pb age data collected by laser ablation multi-collector inductively coupled plasma mass spectrometry, precise geochemical data, and Nd isotope data for igneous rocks from the southeastern Lesser Xing’an Range (SE LXR). The results indicate that the formation ages as follows: Maojiatun alkaline granite, 207.2 ± 0.84 Ma and 204.6 ± 0.93 Ma; Diorite porphyrite, 164.5 ± 0.97 Ma; and Tieli syenogranite, 186.7 ± 1.50 Ma. The alkaline granite has high silicon, potassium, alkali, and FeOT contents; it is enriched in high field strength elements, Zr, Hf, Th, Rb, and U; is depleted in Ba, Sr, Nb, Ta, P, Ti, etc.; and has high ratios of 10000Ga/Al. It shows an A2-type granite affinity. The Tieli alkali-feldspar granite has high total alkali contents and is enriched in high field strength elements and rare earth elements and depleted in Sr, Ba, Ti, and P, and shows varying degrees of alkalinity. Rocks from SE LXR display similar εNd (t) values with corresponding to Nd model ages of 1095 to 813 Ma. The igneous rocks from the SE LXR are proposed to be derived from melting of the Neoproterozoic lower crust and potential magma mixing with ancient crystalline basement. The formation of the Maojiatun alkaline granite occurred in response to a postorogenic event following the closure of the Paleo-Asian Ocean. However, the SE LXR exhibited an extensional back-arc tectonic setting in the Early Jurassic. The Middle Jurassic diorite porphyrite could be related to the temporary stagnation of the westward subduction of the Paleo-Pacific plate.

Field, geochemical, and isotopic evidence for magma mixing and assimilation and fractional crystallization processes in the Quottoon Igneous Complex, northwestern British Columbia and southeastern Alaska

1999 ◽  
Vol 36 (5) ◽  
pp. 819-831 ◽  
Author(s):  
J B Thomas ◽  
A K Sinha
Keyword(s):  
British Columbia ◽  
Fractional Crystallization ◽  
Magma Mixing ◽  
Parental Magma ◽  
Geochemical Data ◽  
Igneous Complex ◽  
Source Regions ◽  
Magmatic Body ◽  
Color Indices ◽  
Lower Crustal

The quartz dioritic Quottoon Igneous Complex (QIC) is a major Paleogene (65-56 Ma) magmatic body in northwestern British Columbia and southeastern Alaska that was emplaced along the Coast shear zone. The QIC contains two different igneous suites that provide information about source regions and magmatic processes. Heterogeneous suite I rocks (e.g., along Steamer Passage) have a pervasive solid-state fabric, abundant mafic enclaves and late-stage dikes, metasedimentary screens, and variable color indices (25-50). The homogeneous suite II rocks (e.g., along Quottoon Inlet) have a weak fabric developed in the magmatic state (aligned feldspars, melt-filled shears) and more uniform color indices (24-34) than in suite I. Suite I rocks have Sr concentrations <750 ppm, average LaN/YbN = 10.4, and initial 87Sr/86Sr ratios that range from 0.70513 to 0.70717. The suite II rocks have Sr concentrations >750 ppm, average LaN/YbN = 23, and initial 87Sr/86Sr ratios that range from 0.70617 to 0.70686. This study suggests that the parental QIC magma (initial 87Sr/86Sr approximately 0.706) can be derived by partial melting of an amphibolitic source reservoir at lower crustal conditions. Geochemical data (Rb, Sr, Ba, and LaN/YbN) and initial 87Sr/86Sr ratios preclude linkages between the two suites by fractional crystallization or assimilation and fractional crystallization processes. The suite I rocks are interpreted to be the result of magma mixing between the QIC parental magma and a mantle-derived magma. The suite II rocks are a result of assimilation and fractional crystallization processes.

Cambrian magmatic flare-up, central Tibet: Magma mixing in proto-Tethyan arc along north Gondwanan margin

2021 ◽  
Author(s):  
Pei-yuan Hu ◽  
Qing-guo Zhai ◽  
Peter A. Cawood ◽  
Guo-chun Zhao ◽  
Jun Wang ◽  
...  
Keyword(s):  
Magma Mixing ◽  
Geochemical Data ◽  
Early Paleozoic ◽  
East African ◽  
Lhasa Terrane ◽  
The North ◽  
Magmatic Rocks ◽  
East African Orogen ◽  
Andean Type ◽  
Central Tibet

Accompanying Gondwana assembly, widespread but diachronous Ediacaran−early Paleozoic magmatism of uncertain origin occurred along the supercontinent’s proto-Tethyan margin. We report new geochemical, isotopic, and geochronological data for Cambrian magmatic rocks (ca. 500 Ma) from the Gondwana-derived North Lhasa terrane, located in the present-day central Tibetan Plateau. The magmatic rocks are composed of basalts, gabbros, quartz monzonites, granitoids (with mafic microgranular enclaves), and rhyolites. Nd-Hf isotopic and whole-rock geochemical data indicate that these rocks were probably generated by mixing of mantle-derived mafic and crust-derived felsic melts. The mantle end-member volumes of mafic, intermediate, and felsic rocks are ∼75%−100%, 50%−60%, and 0−30%, respectively. Integration of our new data with previous studies suggests that the North Lhasa terrane experienced long-term magmatism through the Ediacaran to Ordovician (ca. 572−483 Ma), with a magmatic flare-up at ca. 500 Ma. This magmatism, in combination with other Ediacaran−early Paleozoic magmatism along the proto-Tethyan margin, was related to an Andean-type arc, with the magmatic flare-up event related to detachment of the oceanic slab following collisional accretion of Asian microcontinental fragments to northern Gondwana. Diachroneity of the proto-Tethyan arc system along the northern Gondwanan margin (ca. 581−531 Ma along the Arabian margin and ca. 512−429 Ma along the Indian-Australian margin) may have been linked to orogenesis within Gondwana. The North Lhasa terrane was probably involved in both Arabian and Indian-Australian proto-Tethyan Andean-type orogens, based on its paleogeographic location at the northern end of the East African orogen.

scholarly journals A Geochemical Overview of Mid-Archaean Metavolcanic Rocks from Southwest Greenland

Geosciences ◽  
2018 ◽  
Vol 8 (7) ◽  
pp. 266 ◽  
Author(s):  
Kristoffer Szilas
Keyword(s):  
Magma Mixing ◽  
Geochemical Data ◽  
Calc Alkaline ◽  
Present Contribution ◽  
Data Set ◽  
Basaltic Rocks ◽  
The North ◽  
Metavolcanic Rocks ◽  
Geochemical Analyses ◽  
Southwest Greenland

The present contribution reviews bulk-rock geochemical data for mid-Archaean (ca. 3075–2840 Ma) metavolcanic rocks from the North Atlantic Craton of southwest Greenland. The data set includes the most recent high quality major and trace element geochemical analyses for ten different supracrustal/greenstone belts in the region. When distilling the data set to only include the least altered metavolcanic rocks, by filtering out obviously altered samples, mafic/ultramafic cumulate rocks, late-stage intrusive sheets (dolerites) and migmatites, the remaining data (N = 427) reveal two fundamentally distinct geochemical suites. The contrasting trends that emerge from the filtered geochemical data set, which best represents the melt compositions for these mid-Archaean metavolcanic rocks are: (1) tholeiitic (mainly basaltic) versus (2) calc-alkaline (mainly andesitic). These two rock suites are effectively separated by their La/Sm ratios (below or above three, respectively). It is demonstrated by geochemical modelling that the two contrasting suites cannot be related by either fractional crystallization or crustal assimilation processes, despite occurring within the same metavolcanic sequences. The tholeiitic basaltic rocks were directly mantle-derived, whereas the petrogenesis of the calc-alkaline andesitic rocks involve a significant (>50%) felsic component. The felsic contribution in the calc-alkaline suite could either represent slab-melt metasomatism of their mantle source, mafic-felsic magma mixing, or very large degrees of partial melting of mafic lower crust. At face value, the occurrence of andesites, and the negative Nb-Ta-Ti-anomalies of both suites, is consistent with a subduction zone setting for the origin of these metavolcanic rocks. However, the latter geochemical feature is inherent to processes involving crustal partial melts, and therefore independent lines of evidence are needed to substantiate the hypothesis that plate tectonic processes were already operating by the mid-Archaean.

Digital Concentration-Distribution Models – tools for a describing heterogeneity of the hybridized magmatic mass as reflected in elemental concentration of growing crystal

2012 ◽  
Vol 62 (1) ◽  
pp. 129-141 ◽  
Author(s):  
Michał Śmigielski ◽  
Ewa Słaby ◽  
Andrzej Domonik
Keyword(s):  
Crystal Growth ◽  
Concentration Distribution ◽  
Elemental Concentration ◽  
Magma Mixing ◽  
Geochemical Data ◽  
Distribution Models ◽  
Mixing Processes ◽  
Solid Models ◽  
Icp Ms ◽  
Crystal Growth Mechanism

ABSTRACT Śmigielski, M., Słaby, E. and Domonik, A. 2012. Digital Concentration-Distribution Models - tools for a describing heterogeneity of the hybridized magmatic mass as reflected in elemental concentration of growing crystal. ActaGeologica Polonica, 62 (1), 129-141. Warszawa. Raster digital models (digital concentration-distribution models - DC-DMs) as interpolations of geochemical data are proposed as a new tool to depict the crystal growth mechanism in a magmatic environment. The Natural Neighbour method is proposed for interpolation of Electron Microprobe Analysis (EMPA) data; the Natural Neighbour method and Kriging method are proposed for interpolating data collected by the LA-ICP-MS method. The crystal growth texture was analysed with the application of DC-DM derivatives: 3D surface models, shaded relief images, aspect and slope maps. The magmatic mass properties were depicted with the application of solid models. Correlation between the distributions of two elements on a single crystal transect was made by operations on the obtained raster DC-DMs. The methodology presented is a universal one but it seems to be significant for the depiction of magma mixing processes and the heterogeneity of the magmatic mass.

A geochemical study of two peraluminous granites from south-central Iberia: the Nisa-Albuquerque and Jalama batholiths

1999 ◽  
Vol 63 (1) ◽  
pp. 85-104 ◽  
Author(s):  
J. A. Ramirez ◽  
L. G. Menendez
Keyword(s):  
Fractional Crystallization ◽  
Magma Mixing ◽  
Geochemical Data ◽  
Magmatic Differentiation ◽  
Peraluminous Granite ◽  
South Central ◽  
Geochemical Study ◽  
Peraluminous Granites ◽  
Magma Pulses ◽  
Fractional Crystallization Process

AbstractIn this paper we present new petrological and geochemical data for two peraluminous granite batholiths (Nisa Alburquerque and Jalama batholiths) representative of the ‘Araya-type’ granites of the Central-Iberian Zone. Both granites are composite with several facies (monzogranites and leucogranites) that can be grouped into two main granite units: the external units and central units. Intrusive relationships and lack of geochemical coherence between the central and external units indicate that they are not comagmatic but represent different pulses. The central units of both batholiths are petrologically and geochemically different. On the other hand, external units show a lot of similarities and are the main object of this study. The main characteristics of the external granites can be interpreted in terms of an incomplete fractional crystallization process of early mineral phases (plg + Kf + bt) which probably took place at the level of emplacement. Other possible mechanisms of magmatic differentiation (magma mixing, restite unmixing, sequential melting) can be discarded based on field, petrography and geochemical data. We propose that the ‘Araya-type’ granites are formed by the intrusion of distinct magma pulses (central and external). Further evolution within each pulse can be due to incomplete fractional crystallization possibly taking place at the emplacement level.

scholarly journals Geochemistry of volcanic flows of Nakora area of Malani igneous suite, Northwestern India: Constraints on magmatic evolution and petrogenesis

2020 ◽  
Vol 12 (1) ◽  
pp. 66-82
Author(s):  
Naresh Kumar ◽  
Naveen Kumar
Keyword(s):  
Magma Mixing ◽  
Crustal Contamination ◽  
Data Bank ◽  
Lava Flows ◽  
Geochemical Data ◽  
Magmatic Evolution ◽  
Malani Igneous Suite ◽  
Potential Mineralization ◽  
Spider Diagrams ◽  
Representative Samples

The geochemical characteristics of volcanic flows of Nakora area of Malani Igneous Suite have been determined to understand their magmatic  evolution and petro-genetic aspects. Geochemically, they are high in silica, total alkalis, high field strength elements (HFSE), low ion lithophile elements (LILE), rare metals and rare earth elements; represent A-type affinity with potential mineralization associations. Here, we carried out average geochemical data bank of representative samples of 44 individual lava flows of isolated hill-locks. The relative enrichment of trace elements and negative anomalies of Sr, Eu, P and Ti in the multi-element spider diagrams suggests that the emplacement of the lava flows was controlled by complex magmatic processes i.e. fractional crystallization, partial melting, magma mixing, crustal contamination and assimilation. Moreover, NRCmagma provides new geochemical approaches to understand geodynamic evolution of MIS and emplaced in plume related extensional geodynamic settings in NW Indian shield. Keywords: Geochemistry; Volcanic flows; Nakora; Malani Igneous Suite; Rajasthan; Rodina

scholarly journals GEOCHEMICAL CHARACTERISTICS OF THE ERENLERDAGI VOLCANICS, KONYA, CENTRAL TURKEY

2017 ◽  
Vol 50 (4) ◽  
pp. 2057
Author(s):  
C. Uyanık ◽  
K. Koçak
Keyword(s):  
Fractional Crystallization ◽  
Magma Mixing ◽  
Primitive Mantle ◽  
Geochemical Data ◽  
Calc Alkaline ◽  
High K ◽  
Microgranular Enclaves ◽  
Mafic Microgranular Enclaves ◽  
Central Turkey ◽  
Pyroclastic Fall

Late Miocene to Pliocene volcanism produced lava domes with mafic microgranular enclaves (MMEs), nuée ardentes and pyroclastic fall and flow (ignimbrites) deposits in the WSW and NW of Konya city. All samples are predominantly high K-calc alkaline in composition but calc-alkaline and shoshonitic composition also exist. The felsic volcanics are mainly dacite, andesite, basaltic trachyandesite and rare trachyandesite in compositon. But, the MMEs have basaltic andesite and andesite compositon. SiO2 increases with decreasing TiO2, FeOt, MgO and CaO, suggesting fractional crystallization of mafic minerals. All samples have fractionated chondritenormalised REE pattern (La/YbN: 6.7-18.1), and negative Eu anomaly (Eu/Eu*: 0.67- 0.89), indicating plagioclase fractionation. In primitive mantle-normalized spider diagram, the samples show an enrichment in large ion litophile elements (LILE) such as Cs and Ba, and depletion in high field strength elements (HFSE), e.g. Dy and Y. They show negative Nb, Ta and Ti anomalies, indicating a subduction signature for their genesis. Based on geochemical data, the volcanics are suggested to have been formed by Assimilation-Fractional Crystallization (AFC) and/or magma mixing process. Various geotectonic diagrams imply volcanic arc to post collisional setting for the samples.

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