The source of Fengjia and Langxi barite-fluorite deposits in southeastern Sichuan, China: evidence from rare earth elements and S, Sr, and Sm-Nd isotopic data

2016 ◽  
Vol 52 (3) ◽  
pp. 470-488 ◽  
Author(s):  
Hao Zou ◽  
Yi Fang ◽  
Shou-Ting Zhang ◽  
Qiang Zhang
1993 ◽  
Vol 30 (12) ◽  
pp. 2305-2314 ◽  
Author(s):  
J. H. Sevigny ◽  
R. R. Parrish

In the Middle Jurassic Nelson Batholith, southern British Columbia, young 40Ar/39Ar ages (i.e., 50–60 Ma) and distorted isobaric surfaces in the batholith suggest the possibility of Paleocene granitic plutonism. We present the results of a study undertaken to evaluate this possibility. Geochemical criteria successfully distinguish a suite of granitoids within the Nelson Batholith that differ from Nelson granites of similar SiO2 content. The granitoid suite is composed of 71.6–75.7 wt.% SiO2 leucocratic biotite granite and quartz monzonite with strong enrichments in alkaline, alkaline earth, and rare earth elements. Nd and Pb isotopic compositions suggest that biotite granite and quartz monzonite are not related. Biotite granite yields a U–Pb age of 158.9 ± 0.6 Ma (concordant zircons). Quartz monzonite crystallized at 61 ± 1 Ma, based on interpretation of titanite and zircon analyses. Zircons from this sample lie along a line from 61 to 160 Ma and demonstrate the presence of Middle Jurassic inheritance. Based on its petrographic and isotopic similarity to other Middle Jurassic plutons in the Nelson Batholith – Valhalla Complex area, we include the 159 Ma biotite granite with the Jurassic plutonic suite. This result demonstrates that magmatism in southern British Columbia was active at least until the early Late Jurassic (Oxfordian). The Paleocene (61 Ma) quartz monzonite that intrudes the southern Nelson Batholith is the structurally highest occurrence of "Ladybird" granite yet documented in southern British Columbia. Comparison of new and published geochemical and isotopic data for Paleocene granitoids throughout the southern Omineca Belt, British Columbia, suggests that these granitoids were not derived from a single, old crustal source.


2020 ◽  
Vol 12 (1) ◽  
pp. 452-478
Author(s):  
Sergio Speziale ◽  
Francesca Castorina ◽  
Paolo Censi ◽  
Celso de Barros Gomes ◽  
Leila Soares Marques ◽  
...  

AbstractWe present a comprehensive overview of the geochemical characteristics and evolution of the carbonatites from the southern Brazilian Platform (Paraná Basin). The carbonatites from different complexes display large compositional variability in terms of abundances of incompatible and rare earth elements. This is in agreement with an origin from heterogeneous lithospheric sources, as confirmed by isotopic data (see Speziale et al., this issue). The characteristic major and trace element abundances of these carbonatites present compelling evidence for invoking liquid unmixing as the main mechanism of their formation and evolution albeit few exceptions. We propose an evolutionary trend for the Brazilian carbonatites, which can be summarized as following: exsolution of the primary Ca- or Mg-carbonatitic liquids systematically takes place at the phonolite-peralkaline phonolite stage of magma differentiation; this is followed by progressive Fe-enrichment and by final emplacement of fluorocarbonatites associated with hydrothermal fluids.


1962 ◽  
Vol 18 (4) ◽  
pp. 1127-1153
Author(s):  
V FASSEL ◽  
R CURRY ◽  
R KNISELEY

2020 ◽  
Vol 4 (2) ◽  
pp. 599-604
Author(s):  
Michael A. Onoja ◽  
P. H. Bukar ◽  
C. U. Omeje ◽  
A. M. Adamu

Instrumental neutron activation analysis (INAA) technique was used to investigate the abundance and distribution of rare earth elements (REE) in soil around Kaduna Refinery. The aim of the study is to assess the rare elements potential of Nigeria for economic exploitation. Five REEs (La, Dy, Eu, Yb, and Lu) were detected in varying concentrations ranging from a minimum of 0.6 µg/g (Lu) to a maximum of 249.0 µg/g (La). The elements existed with trends consistent with the natural pattern of REEs in soil, showing significant Eu and Dy anomalies which characterize upper plains and flood plains. The levels of REEs in soil in the study area were generally slightly above background levels, with minimal (La, Dy, and Eu), moderate (Yb), and significant (Lu) enrichments and trending: Lu ˃Yb ˃ Eu ˃ Dy ˃ La. The abundance of the REEs investigated cannot establish a potential of Nigeria for economic exploitation of the mineral, hence, rare earth project in the study area is not viable at the moment.


1986 ◽  
Author(s):  
Ingeborg Hinz ◽  
Peter Kuhn ◽  
Ursula Vetter ◽  
Eberhard Warkentin

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