Journal cover Journal topic
Stephan Mueller Special Publication Series An open-access serial publication for refereed proceedings and special publications
Journal topic
Volume 4
Stephan Mueller Spec. Publ. Ser., 4, 97-109, 2009
https://doi.org/10.5194/smsps-4-97-2009
© European Geosciences Union 2009
Stephan Mueller Spec. Publ. Ser., 4, 97-109, 2009
https://doi.org/10.5194/smsps-4-97-2009
© European Geosciences Union 2009

  17 Sep 2009

17 Sep 2009

The Tommot pluton: a Middle Paleozoic rift-related alkaline gabbro and syenite complex, Yakutia, northeast Russia

V. A. Trunilina1, P. W. Layer2, L. M. Parfenov*,†, A. I. Zaitsev1, and Y. S. Orlov3 V. A. Trunilina et al.
  • 1Yakutian Diamond and Precious Metal Geology Institute, Siberian Branch, Russian Academy of Sciences, 39 Lenin Prospect, 677891, Yakutsk, Russia
  • 2Geophysical Institute, University of Alaska Fairbanks, Fairbanks, AK 99775, USA
  • 3Yakutian State Geological Expedition, 13 Kirov Street, 677891, Yakutsk, Russia
  • *formaly at: Yakutian Diamond and Precious Metal Geology Institute, Siberian Branch, Russian Academy of Sciences, 39 Lenin Prospect, 677891, Yakutsk, Russia
  • deceased

Abstract. The Tommot pluton is located within the continental Omulevka terrane of the inner zone of the Verkhoyansk-Kolyma Mesozoic orogen. It is a small complex (~12 km2) composed of alkaline-ultramafic rocks, alkaline and subalkaline gabbroids, and alkaline and quartz syenites. The pluton is unique both in the composition and age of its constituent rocks. Mineralogical-petrographical and geochemical studies of the rocks indicate that the alkaline rocks resulted from the melting of depleted mantle horizons. K-Ar, Rb-Sr, and 40Ar/39Ar age determinations confirm a Paleozoic age of the rocks. Formation of the alkaline rocks is related to Middle Paleozoic rifting which occurred as two discrete events: a Late Devonian event, which affected the marginal part of the Siberian continent, and a Late Carboniferous event that reflects internal deformation of the Omulevka terrane or late-stage extension. A spatially associated alkali granite, the Somnitel'nyy pluton, is Late Jurassic–Early Cretaceous in age and is synchronous with accretion of the Kolyma-Omolon Superterrane to Siberia in the Mesozoic.

Publications Copernicus
Download
Citation
Share