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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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TL;DR: The metamorphic belt in central Jiangxi, located in the compound terrain within the Cathaysia, Yangtze Block and Caledonian fold zone of South China, is composed dominantly of meta-argillo-are-naceous rocks, with minor amphibolite.
Abstract: The metamorphic belt in central Jiangxi, located in the compound terrain within the Cathaysia, Yangtze Block and Caledonian fold zone of South China, is composed dominantly of meta-argillo-are-naceous rocks, with minor amphibolite. These rocks underwent amphibolite-facies metamorphism. The meta-argillo-arenaceous rocks show large variations in major element composition, but have similar REE patterns and trace element composition, incompatible element and LIE enrichments [high Th/Sc (0.57−3.59), La/Sc (1.46−12.4), La/Yb (5.84−19.0)] and variable Th/U ratios, with ΣREE=129−296µg/g, δEu=0.51−0.86, and (La/Yb)N=3.95−12.9. The Nd isotopic model agest DM of these rocks vary from 1597 to 2124 Ma. Their143Nd/144Nd values are low [ɛNd(0)=−11.4 to −15.8]. Some conclusions have been drawn as follows: (1) The metamorphic rocks in central Jiangxi Province are likely formed in a tectonic environment at the passive continental margin of the Cathaysia massif. (2) The metamorphosed argillo-arenaceous rocks are composed dominantly of upper crustal-source rocks (Al- and K-rich granitic or/and sedimentary rocks of Early Proterozoic), which experienced good sorting, slow deposition and more intense chemical weathering. (3) According to the whole-rock Sm-Nd isochron ages (1113±49 to 1199±26 Ma) of plagioclase-amphibole (schist) and Nd isotopic model aget DM (1597−2124 Ma) of meta-argillo-arenaceous rocks, the metamorphic belt in central Jiangxi Province was formed during the Middle Proterozoic (1100−1600 Ma).

6 citations

Journal ArticleDOI
TL;DR: Based on conservation of energy principle and heat flow data in China continent, the upper limit of 1.3 μW/m3 heat production is obtained for continental crust in China.
Abstract: Based on conservation of energy principle and heat flow data in China continent, the upper limit of 1.3 μW/m3 heat production is obtained for continental crust in China. Furthermore, using the data of heat flow and helium isotope ratio of underground fluid, the heat productions of different tectonic units in China continent are estimated in range of 0.58–1.12 μW/m3 with a median of 0.85 μW/m3. Accordingly, the contents of U, Th and K2O in China crust are in ranges of 0.83–1.76 μg/g, 3.16–6.69 μg/g, and 1.0%–2.12%, respectively. These results indicate that the abundance of radioactive elements in the crust of China continent is much higher than that of Archean crust; and this fact implies China's continental crust is much evolved in chemical composition. Meanwhile, significant lateral variation of crustal composition is also exhibited among different tectonic units in China continent. The crust of eastern China is much enriched in incompatible elements such as U, Th and K than that of western China; and the crust of orogenic belts is more enriched than that of platform regions. It can also be inferred that the crusts of eastern China and orogenic belts are much felsic than those of western China and platform regions, respectively, derived from the positive correlation between the heat production and SiO2 content of bulk crust. This deduction is consistent with the results derived from the crustal seismic velocity data in China. According to the facts of the lower seismic velocity of China than the average value of global crust, and the higher heat production of China continent compared with global crust composition models published by previous studies, it is deduced that the average composition models of global continent crust by Rudnick and Fountain (1995), Rudnick and Gao (2003), Weaver and Tarney (1984), Shaw et al. (1986), and Wedepohl (1995) overestimate the abundance of incompatible elements such as U, Th and K of continental crust.

6 citations

01 Jan 2003
TL;DR: Wang et al. as discussed by the authors showed that 11B is an incompatible element and is apt to enter liquid phase and there formed a low value of δ 11B in residuals of metamorphic phase.
Abstract: Proterozoic boron ore deposits in the east part of Liaoning Province belong to sedimentary-metamorphic type According to the study on sedimentations in modern salt lakes, boron minerals in sedimentation are usually borax Borax turned into boron-magnesium minerals and boron-iron minerals etc in regional metalmorphic processes Boron isotopes are different in different boron minerals in eastern Liaoning boron depositsδ 11B value of tourmalines being rich in 10B are rather low or are negative value While δ 11B value of boromagnesites and ludwigites being rich in 11B are quite high, up to +23‰—+174‰ The study on fractionating feature of boron isotope in water and rock interaction, compared with 11B and 10B, shows four characteristics (1) 11B is an incompatible element and is apt to enter liquid phase So there formed a low value of δ 11B in residuals of metamorphic phase (2)During the alteration and metamorphic metasomatism 11B is replaced by silicon in the mineral lattice So δ 11B value decreases in silicification and increases in the desilicification (3)Because 11B is brought in by (OH)-, the value of δ 11B is high in water-rich minerals Hydrothermal depositional tourmaline and hydrothermal metasomatic tourmaline have low or negative 11B values (4) Our recent research shows that there is obvious fraction in distillation process and 11B inclined to enter gas phase This made residual phase and later phase short of 11B to form a low value of δ 11B Based on the above analyses, the authors have proposed that boron deposits in eastern Liaoning Province is the result of metasomatism of magnesian by boric acid solutions, which have generated from regional metamorphic process of hydrothermal sedimentary tourmaline rocks So it is not evaporate-depositional metamorphic ore deposits

6 citations

Journal ArticleDOI
TL;DR: Based on petrographic, geochemical, and zirconological information from this study, the authors presented a particular model of the magma evolution and tin mineralization for the Gejiu tin district.

6 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
20237
202216
202157
202056
201960
201851