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Incompatible element
About: Incompatible element is a research topic. Over the lifetime, 2420 publications have been published within this topic receiving 154052 citations.
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01 Dec 2004
TL;DR: For HREEs (Sm, Er, Lu, Yb), Y, HFSEs (Zr, Hr, Ti), Sc, and Cr, a positive correlation between the partitioning coefficient and temperature was found as discussed by the authors.
Abstract: For HREEs (Sm, Er, Lu, Yb), Y, HFSEs (Zr, Hr, Ti), Sc, and Cr we see a positive correlation between the partitioning coefficient and temperature. The opposite trend is observed for the transition elements (Mn, Co, Ni). No trend is observed between partitioning and temperature for the more highly incompatible elements Ba, U, Th, Pb, Nb, La, and LREEs due, most likely, to problems associated with these elements and contamination.
TL;DR: The geochemical data of the mentioned intrusives on the variation diagrams show that these rocks are categorized into mafic and felsic groups and in terms of magmatic series, they are often from alkaline one as discussed by the authors.
Abstract: Intrusives around Omam (East of Guilan) with gabbro, monzo-gabbro-porphyry, syenite and granite compositions have intruded to upper Cretaceous lavas, sedimentary and pyroclastic rocks. The geochemical data of the mentioned intrusives on the variation diagrams show that these rocks are categorized into mafic and felsic groups and in terms of magmatic series, they are often from alkaline one. Relative continuity between most intrusive mafic rocks data on the variation diagrams and the parallel feature of their rare earth elements patterns clearly show the derivation of this group from a common origin. Based on the severity of changes in strongly compatible elements versus the strongly incompatible elements, the dominant process governing the magmatic evolution for mafic rocks is fractional crystallization. REE patterns for different types of mafic rocks are in parallel with each other and have a uniform and downward slope, while the slope of felsic varieties patterns for LREE is steep and descending and flat for HREE. Based on the La/Sm ratio, it seems that the melts forming mafic rocks are derived from the enriched mantle with spinel lherzolite composition and partial melting degree of 4 to 10 percent. On the tectonic setting discrimination diagrams, the intrusive rocks of the studied area are categorized in the territory of intracontinental rifts.
01 Jan 2004
TL;DR: In this paper, the mid-ocean ridge basalt and the ocean island basalt basalt are compared, and it is shown that the MORBs are depleted in incompatible elements, such as uranium and thorium, while the OIBs are relatively enriched in these elements.
Abstract: he two main sites of the upwelling in the earth mantle are the mid-ocean ridges and the intraplate hotspots, or oceanic islands. Due to different geochemical composition of the basalt in these two sites, we use two different abbreviated terms to describe the lava from these two environments: the MORB (Mid-Ocean Ridge Basalt) and the OIB (Ocean-Island Basalt). In general, geochemists believe that the MORBs come from the upwelling of the shallow convection cell within the upper reservoir, while the OIBs come from the upwelling of the deep-seated upwelling plumes from the lower reservoir. The main proof by which geochemists stand for their idea is: the MORBs are depleted in incompatible elements, such as uranium and thorium, while OIBs are relatively enriched in these elements. This gives a reasonable interpretation for different sources of these two basalts. Besides, the terrestrial heat flow studies also support this idea. The approximately 36 TW of mantle heat output could not be possibly achieved only by the MORB source material, for too few radioactive heat sources; the remainders are thought to be contributed by the deeper materials which are not sampled by the mid-ocean ridge, but instead, by the deep-seated plumes. Therefore, what would be the boundary of the upper and lower convection cells? Several possibilities are provided by geochemists. The 660-km discontinuity is believed to be the most promising boundary between these two reservoirs, for clear olivine phase change from spinel to perovskite and magnesowustite (γ→pv+mw). Recently, a 1600-km barrier was proposed by Kellogg et al. Numerical modeling of the thermochemical convection implies an intrinsically dense layer in the lower mantle, enriched in heat producing elements. The top of this layer ranges from ~1600 km to near CMB, often deflected by downwelling slabs, with plumes developing around local high spots (Fig. 1). Till now, the viewpoints of the geochemists seem clear. However, accompanied with the progress of computer hardware, geophysicians developed the technique of tomography in order to do the “body scanning” inside the earth’s depth. During the past two decades, plenty of interesting results have been published, within most of them are against the double layer convection hypothesis.
TL;DR: In this article , the authors used trace element variations to identify two primary magmas from the Holocene Bayuda Monogenetic Volcanic Field (BMVF) in the north of Sudan.
TL;DR: The Hadji-Abad ultramafic complex in Hormozgan province of Iran has been studied in this paper, showing that it is part of an oceanic lithosphere above suprasubduction zone which has undegone partial melting and mantle metasomatism processes associated with this environment.
Abstract: The mantle peridotites of the Hadji-Abad ultramafic complex in Hormozgan province, show some petrological evolutions of the upper mantle of southern Iran. The complex includes harzburgite, lherzolite, dunite and chromitite. Evidences such as different generations of minerals, lobate boundaries between grains, elongation of cr-spinels and pyroxenes, incongruent melting related textures and exsolution lamellae of clinopyroxene in orthopyroxene show that the rocks in this complex first underwent high temperature-pressure in the upper mantle, and then emplaced in the crust. The chemical composition of chromites in the Hadji Abad dunites and chromitites is similar to that of boninite melts, while, the mineral chemistry of the harzburgitic and lherzolitic show that the host peridotites belong to the upper mantle and have been depleted from incompatible elements due to 15 to 20 percent partial melting. Geo-thermometric calculations reveal that the studied peridotites equilibriated in upper mantle and spinel-peridotite stability field. Using tectonomagmatic discrimination diagrams shows that the Hadji-Abad ultramafic complex is part of an oceanic lithosphere above suprasubduction zone which has undegone partial melting, high temperature deformations and mantle metasomatism processes associated with this environment. These evidences along with the geological and tectonic setting of the Hadji Abad complex adjacent to the Zagros thrust indicate that the complex probably was created in the mantle section under a back-arc basin and then tectonically emplaced as part of Esfandagheh-Hadji-Abad melange in the current situation during the upper Cretaceous. These informations confirm the dependence of the Esfandagheh-Hadji-Abad ophiolite melange on the Neotethyan oceanic lithosphere in southern Iran.