scholarly journals Petrogenesis of Magnesian High-K Granitoids From Bitkine (Centrechad Massif): Major and Trace Elements Constraints

2020 ◽  
Vol 1 (5) ◽  
Author(s):  
Mbaihoudou Diontar ◽  
Jean Claude Doumnang ◽  
Maurice Kwékam ◽  
Zagalo Al-hadj Hamid ◽  
Armand Kagou Dongmo ◽  
...  
Keyword(s):  
Trace Elements ◽  
Trace Element ◽  
Fractional Crystallization ◽  
Major And Trace Elements ◽  
Trace Element Data ◽  
Calc Alkaline ◽  
Element Data ◽  
High K ◽  
Microgranular Enclaves ◽  
Mantle Magma

Major and trace element data were used to constrain the nature and origin of the Bitkine gabbro-diorite magma.The gabbro-diorites of Bitkine within the Guéra Massif, and associated microgranular enclaves consist of plagioclase, k-feldspar, clinopyroxene, amphibole, biotite and quartz. Gabbro-diorites and enclaves are basic to intermediate rocks. They are high-K magnesian calc-alkaline with shoshonite affinity. ΣREE range from 132 to 436 ppm in gabbro-diorites, while they are from 134 to 207 ppm in enclaves. LREE are weakly enriched compared to HREE (La/Yb)N = (12.23 -41.40) and (6.20-31.86) respectively in gabbro-diorites and enclaves. These rocks show a weak negative anomaly in europium (Eu/Eu* = 0.78-1.07). They are rich in Ba and Sr, and show negative anomalies in Nb, Ta and Ti. The Nb/Ta, Rb/Cs and Ba/Nb ratios of the Bitkine gabbro-diorites and their enclaves indicate that they are derived from mantle magma modified by subducted fluids. This magma during its evolution by fractional crystallization was contaminated by crustal materials.

Geochemical contrasts between late Caledonian granitoid plutons of northern, central and southern Scotland

1984 ◽  
Vol 75 (2) ◽  
pp. 259-273 ◽  
Author(s):  
W. E. Stephens ◽  
A. N. Halliday
Keyword(s):  
Trace Elements ◽  
Trace Element ◽  
Incompatible Element ◽  
Geochemical Data ◽  
Wide Sense ◽  
Trace Element Data ◽  
Isotopic Data ◽  
Element Data ◽  
High K ◽  
Mantle Component

ABSTRACTNew major- and trace-element data for granitoid plutons from the Grampian Highlands, the Midland Valley and the Southern Uplands of Scotland are presented and discussed. The study is restricted to ‘late granitoids’ (all younger than 430 Ma); the term ‘granitoid’ is used in a wide sense to encompass all plutonic components of a zoned intrusion of this age, sometimes including diorites and ultrabasic cumulate rocks. The data indicate that as a whole the province is chemically high-K calc-alkalic. Other notable enrichments are in Sr and Ba, and a marked geographical difference in these trace-elements is found between plutons of the SW Grampian Highlands and those of the Southern Highlands, the Midland Valley, and the Southern Uplands. Plutons of the NE Highlands tend to be more geochemically evolved than those further SW and those of the Midland Valley and Southern Uplands.When petrographical and geochemical data are considered, three plutonic suites are recognised: (1) the Cairngorm suite comprising plutons of the NE Highlands, (2) the Argyll suite comprising plutons from the SW Highlands, and (3) the S of Scotland suite comprising plutons from the Southern Highlands, Midland Valley and the Southern Uplands excluding Criffell and the Cairnsmore of Fleet. It is proposed that the more acidic granitoids are dominantly the products of I-type crustal sources, but certain diorites and the more basic members of zoned plutons have a substantial mantle component. The elevated Sr and Ba levels in granitoids of the Argyll suite may reflect the influence of incompatible-element-rich fluids from the mantle in the petrogenesis of this suite. The relatively anhydrous pyroxene-mica diorites of the S of Scotland suite are richer in Ni and Cr and appear to represent mantle-derived melts. The relationships between these data and already published isotopic data are discussed.

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.

Further immobile element data from altered volcanic rocks, Timmins mining area, Ontario

1980 ◽  
Vol 17 (3) ◽  
pp. 419-423 ◽  
Author(s):  
J. F. Da Vies ◽  
R. E. S. Whitehead
Keyword(s):  
Trace Elements ◽  
Trace Element ◽  
Volcanic Rocks ◽  
Mining Area ◽  
Trace Element Data ◽  
Element Data ◽  
Lithostratigraphic Units

The relatively immobile trace elements TiO2, Zr, and Y prove useful for determining the original identity of, and for correlating, metamorphosed and metasomatized Archean volcanic rocks. More than 95% of 366 samples from the Timmins area were found to correspond to the lithostratigraphic units determined independently from structural and stratigraphic decisions based on lithology and top determinations. Trace-element data can be used for distinguishing volcanic units and as an aid in correlation regardless of any petrogenetic interpretations.

Metabentonites in the Moffat Shale Group, Southern Uplands of Scotland: Geochemical evidence of ensialic marginal basin volcanism

1990 ◽  
Vol 127 (3) ◽  
pp. 259-271 ◽  
Author(s):  
R. J. Merriman ◽  
B. Roberts
Keyword(s):  
Trace Elements ◽  
Trace Element ◽  
Late Ordovician ◽  
Trace Element Data ◽  
Geochemical Evidence ◽  
Sialic Crust ◽  
Element Data ◽  
High Concentrations ◽  
Arc Setting ◽  
Back Arc

AbstractMetabentonites occur extensively in the Moffat Shale Group of the Southern Uplands of Scotland. At Dob's Linn 135 metabentonite beds, 1–50 cm thick, occur in Ashgill to Llandovery strata, representing an aggregate thickness of 6 m of compacted ash accumulated over approximately 25 Ma. The metabentonites are characterized by relatively high concentrations of trace elements, including Ba, Cs, Hf, Nb, Rb, Ta, Th, U, Y, Zr and REEs, which were inherited from evolved vitric ash. Immobile trace element data indicate that a spectrum of silicic ash compositions accumulated, ranging from subalkaline to mildly peralkaline. In the late Ordovician N. gracilis to G. persculptus biozones, subalkaline ash falls predominated, whereas peralkaline ash falls predominated in the Llandovery (Silurian) P. acuminatus to M. convolutes biozones, giving way to predominantly subalkaline ash falls during accumulation of the M. sedgwickii to R. maximus biozones. Changeovers in the dominant ash types are marked by increased proportions of ash. The magmas from which the ash types evolved were generated in an ensialic arc transitional to a back-arc setting, and involved attenuated sialic crust and mantle characterized by variable depletion in HFS elements. Lithological, petrological and REE characteristics suggest that the Moffat Shale Group is not exclusively pelagic in origin and probably accumulated in a back-arc basin bordering an ensialic arc terrane.

Movement of Elements between Soil and its Source Rock a Case Form Limestone Soil in Suzhou City, Anhui Province, China

2012 ◽  
Vol 610-613 ◽  
pp. 2904-2907
Author(s):  
Song Chen
Keyword(s):  
Trace Elements ◽  
Source Rock ◽  
Major And Trace Elements ◽  
Anhui Province ◽  
Background Value ◽  
High K ◽  
Suzhou City ◽  
Limestone Soil ◽  
High Migration ◽  
Cu And Zn

The limestone soils and its source rock samples had been collected from Suzhou area for the testing about major and trace elements. The concentration value have been compared with the background and the migration coefficient(K) of element form source rock to soil have been calculated, the result showed: the elements Ca and Th are enrichment, the Al is loss seriously, the Ti, V, Cr, Mn, Zn, Rb, Sr., Zr, and Pb are basic fairly with the background value; the K, Cu, Fe and As are slightly higher than the soil background values; The elements Si, Ti, Mn, Zr, Pb and Th have high K in subsoil layer; the element Fe, Cr, As and Rb have the least K in subsoil layer; the element Al, V, Cu and Zn can be showed disorder with the more high migration coefficient in topsoil.

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