Publication detail

Lithium isotopes in kimberlites, lamproites and lamprophyres as tracers of source components and processes related to supercontinent cycles

KRMÍČEK, L. MAGNA, T. PANDEY, A. CHALAPATHI RAO, N.V. KYNICKÝ, J.

Original Title

Lithium isotopes in kimberlites, lamproites and lamprophyres as tracers of source components and processes related to supercontinent cycles

Type

book chapter

Language

English

Original Abstract

Our pilot study reveals potential Li isotope fingerprints recorded in the Mesoproterozoic (c. 1.4– 1.1 Ga) kimberlites, lamproites and lamprophyres from the Eastern Dharwar Craton and Paleocene (62 Ma) orangeite from the Bastar Craton in India. The new data are interpreted in the context of available Li isotope composition of lamproitic to lamprophyric rocks occurring in Variscan (Bohemian Massif ) and Alpine–Himalayan (SW Tibet) orogenic belts formed in response to Gondwana–Pangea amalgamation and break-up. As a result of the development of supercontinents, kimberlites from the Eastern Dharwar Craton and ‘orangeite’ from the Bastar Craton show clear presence of a component with a heavy Li isotope signature (δ7 Li up to 9.7‰) similar to ancient altered oceanic crust, whereas the Eastern Dharwar Craton lamproites (2.3–6.3‰) and lamprophyres (3.3–6.7‰) show Li isotope signatures indicative of a dominant contribution from heterogeneous lithospheric mantle. Variscan lamprophyric to lamproitic rocks and post-collisional mantle-derived (ultra)potassic volcanic rocks from SW Tibet, i.e. rocks from the orogenic belts outside the cratonic areas, are characterized by a clear Li isotope shift towards an isotopically lighter component (δ7Li as low as – 9.5‰) comparable with the involvement of evolved continental crust and high-pressure metamorphic rocks in their orogenic mantle source. Such components with isotopically light Li are strikingly missing in the source of cratonic kimberlites, lamproites and lamprophyres.

Keywords

lithium isotopes; kimberlites; lamproites; lamprophyres; supercontinent cycles

Authors

KRMÍČEK, L.; MAGNA, T.; PANDEY, A.; CHALAPATHI RAO, N.V.; KYNICKÝ, J.

Released

9. 2. 2022

Publisher

Geological Society of London

Location

Bath

ISBN

978-1-78620-543-8

Book

Lamprophyres, Lamproites and Related Rocks: Tracers to Supercontinent Cycles and Metallogenesis

Edition

513

Edition number

1

ISBN

0305-8719

Periodical

Geological Society Special Publication

Year of study

513

Number

1

State

unknown

Pages from

209

Pages to

236

Pages count

28

URL

https://sp.lyellcollection.org/content/513/1/209

BibTex

@inbook{BUT176726,
  author="Lukáš {Krmíček} and Tomáš {Magna} and Ashutosh {Pandey} and N.V. {Chalapathi Rao} and Jindřich {Kynický}",
  title="Lithium isotopes in kimberlites, lamproites and lamprophyres as tracers of source components and processes related to supercontinent cycles",
  booktitle="Lamprophyres, Lamproites and Related Rocks: Tracers to Supercontinent Cycles and Metallogenesis",
  year="2022",
  publisher="Geological Society of London",
  address="Bath",
  series="513",
  edition="1",
  pages="209--236",
  doi="10.1144/SP513-2021-60",
  isbn="978-1-78620-543-8",
  url="https://sp.lyellcollection.org/content/513/1/209"
}