Rare Earth and High Field Strength Element Geochemistry of the Kidd Creek Rhyolites, Abitibi Greenstone Belt, Canada

1999 ◽  
pp. 457-483
Keyword(s):  
Rare Earth ◽  
Field Strength ◽  
Greenstone Belt ◽  
High Field ◽  
High Field Strength Element ◽  
High Field Strength ◽  
Element Geochemistry ◽  
Abitibi Greenstone Belt

Origin of the Late Devonian Weekend lamprophyre dykes, Meguma Zone, Nova Scotia

1993 ◽  
Vol 30 (12) ◽  
pp. 2295-2304 ◽  
Author(s):  
M. C. Tate ◽  
D. B. Clarke
Keyword(s):  
Rare Earth ◽  
Field Strength ◽  
Rare Earth Element ◽  
High Field ◽  
Earth Element ◽  
High Field Strength Element ◽  
Late Devonian ◽  
High Field Strength ◽  
Element Abundances ◽  
Depleted Mantle

The Weekend dykes consist of 10 Late Devonian spessartite lamprophyres cropping out within the allochthonous Meguma lithotectonic terrane of the northern Appalachians. The dykes have characteristic panidiomorphic textures, with seriate phenocrysts of amphibole, clinopyroxene, and rare biotite set in a groundmass of intergrown plagioclase, K-feldspar, and quartz, with deuteric calcite and epidote. All dykes intruded during one magmatic episode (ca. 370 Ma) following terrane accretion of the Acadian Orogeny. The unaltered Weekend dykes show restricted major element variation (SiO2 54–58 wt.%, Al2O3 14–16 wt.%, MgO 7–11 wt.%, and total alkalies 2.4–5.5 wt.%) and have high Mg# (71–80) and moderate to high concentrations of Ni (69–278 ppm) and Cr (390–992 ppm). Large ion lithophile element (e.g., Sr, Ba 294–1194 ppm) and light rare earth element (13–67CN) abundances are high relative to high field strength element (e.g., Nb, Ta, Y 0.45–26 ppm) and heavy rare earth element (6–30CN) abundances. Geochemical variation largely corresponds to minor phenocryst fractionation, but high Mg# indicate the primitive nature of most dykes and preclude significant evolution of lamprophyric magmas in the crust. Incompatible element enrichments coupled with depleted mantle high field strength element abundances probably require a melt derived from reenriched lithospheric mantle sources, whereas Nb depletion and the volatile-rich mineralogy suggest metasomatic contributions from subducted ocean lithosphere. Geochemical comparisons with continental margin arc basalts and immobile element tectono-magmatic discrimination reinforce a subduction model for the Weekend dykes and strongly suggest active subduction prior to the emplacement of the Meguma terrane.

scholarly journals Influence of Sample Pretreatment on the Analysis of High Contents of Rare-Earth and High Field Strength Elements in Geological Samples by ICP-AES and ICP-MS (Case Study of the Tomtor Deposit)

2020 ◽  
pp. 593-605
Author(s):  
Bagai-ool Yu. Saryg-ool ◽  
Lidiya N. Bukreeva ◽  
Irina N. Myagkaya ◽  
Aleksandr V. Tolstov ◽  
Elena V. Lazareva ◽  
...  
Keyword(s):  
Rare Earth ◽  
Field Strength ◽  
Inductively Coupled Plasma ◽  
High Field ◽  
Sample Pretreatment ◽  
Emission Spectrometry ◽  
Geological Samples ◽  
High Field Strength ◽  
Inductively Coupled ◽  
Icp Ms

Influence of sample pretreatment on the analysis of the high contents of rare earth (REE) and high field strength (HFSE) elements in geological samples by inductively coupled plasma atomic emission spectrometry (ICP-AES) and inductively coupled plasma mass spectrometry (ICP-MS) was studied. The rocks and rich ores of the Tomtor Nb-REE deposit were explored. Complete dissolution of the geological samples with a high content of “refractory” minerals has been achieved using fusion with a sodium peroxide. The results obtained by ICP-AES and ICP-MS after chemical dissolution are comparable with the results obtained by the XRF-SR without chemical pretreatment

Sign in / Sign up

Export Citation Format

Share Document