Detail publikace

Carbonatites of Tarim (NW China): First evidence of crustal contribution in carbonatites from a large igneous province

SONG, W. XU, C. CHAKHMOURADIAN, A. KYNICKÝ, J. HUANG, K. ZHANG, Z.

Originální název

Carbonatites of Tarim (NW China): First evidence of crustal contribution in carbonatites from a large igneous province

Typ

článek v časopise ve Web of Science, Jimp

Jazyk

angličtina

Originální abstrakt

Many carbonatites are associated both spatially and temporally with large igneous provinces (LIPs), and considered to originate from a mantle plume source lacking any contribution from recycled crustal materials. Here, we report an occurrence of carbonatite enriched in rare-earth elements (REE) and associated with the Tarim LIP in northwestern China The Tarim LIP comprises intrusive and volcanic products of mantle plume activity spanning from similar to 300 to 280 Ma. The carbonatites at Wajilitage in the northwestern part of Tarim are dominated by calcite and dolomite varieties, and contain abundant REE minerals (principally, monazite and REE-fluorcarbonates). Th-Pb age determination of monazite yielded an emplacement age of 266 +/- 5.3 Ma, i.e. appreciably younger than the eruption age of flood basalts at similar to 290 Ma. The carbonatites show low initial Sr-87/Sr-86 (0.7037-0.7041) and high epsilon(Nd(t)) (1.2-4)values, which depart from the isotopic characteristics of plume-derived basalts and high-Mg picrites from the same area. This indicates that the Wajilitage carbonatites derived from a mantle source isotopically distinct from the one responsible for the voluminous (ultra)mafic volcanism at Tarim. The carbonatites show delta Mg-26(DSM3) values (-0.99 to -0.65%.) that are significantly lower than those in typical mantle-derived rocks and rift carbonatites, but close to marine sediments and orogenic carbonatites. We propose that the carbonatites in the Tarim LIP formed by decompressional melting of recycled sediments mixed with the ambient mantle peridotite. The enriched components in the Tarim plume could be accounted for by the presence of recycled sedimentary components in the subcontinental mantle.

Klíčová slova

Carbonatite; Large igneous province; Plume; Subducted sediments; Carbonate recycling

Autoři

SONG, W.; XU, C.; CHAKHMOURADIAN, A.; KYNICKÝ, J.; HUANG, K.; ZHANG, Z.

Vydáno

1. 6. 2017

ISSN

0024-4937

Periodikum

LITHOS

Ročník

282

Číslo

1

Stát

Norské království

Strany od

1

Strany do

9

Strany počet

9

BibTex

@article{BUT142031,
  author="Wenlei {Song} and Cheng {Xu} and Anton R. {Chakhmouradian} and Jindřich {Kynický} and KangJun {Huang} and ZhenLiang {Zhang}",
  title="Carbonatites of Tarim (NW China): First evidence of crustal contribution in carbonatites from a large igneous province",
  journal="LITHOS",
  year="2017",
  volume="282",
  number="1",
  pages="1--9",
  doi="10.1016/j.lithos.2017.02.018",
  issn="0024-4937"
}