de.mpg.escidoc.pubman.appbase.FacesBean
English
 
Help Guide Disclaimer Contact us Login
  Advanced SearchBrowse

Item

ITEM ACTIONSEXPORT

Released

Journal Article

Partial melting and assimilation of dolomitic xenoliths by mafic magma: the Ioko-Dovyren intrusion (North Baikal region, Russia)

MPS-Authors
http://pubman.mpdl.mpg.de/cone/persons/resource/persons100871

Brügmann,  G. E.
Geochemistry, Max Planck Institute for Chemistry, Max Planck Society;

Locator
There are no locators available
Fulltext (public)
There are no public fulltexts available
Supplementary Material (public)
There is no public supplementary material available
Citation

Wenzel, T., Baumgartner, L. P., Brügmann, G. E., Konnikov, E. G., & Kislov, E. V. (2002). Partial melting and assimilation of dolomitic xenoliths by mafic magma: the Ioko-Dovyren intrusion (North Baikal region, Russia). Journal of Petrology, 43(11), 2049-2074.


Cite as: http://hdl.handle.net/11858/00-001M-0000-0014-9056-2
Abstract
A petrological study was carried out on Mg-skarn-bearing dunite cumulates that are part of the Neo-Proterozoic Ioko-Dovyren intrusion (North Baikal region, Russia). Skarn xenoliths contain brucite pseudomorphs after periclase, forsterite and Cr-poor spinel. Fine-grained forsterite-spinel skarns occur with the brucite skarns or as isolated schlieren. Field relationships reveal that the Mg-skarns formed from silica-poor dolomitic xenoliths by interaction with the mafic magma of the Ioko-Dovyren intrusion. Rapid heating of dolomitic xenoliths by the mafic magma caused the decomposition of dolomite into calcite + periclase, releasing much CO2. Further heating quantitatively melted the calcite. A periclase-rich restite was left behind after extraction of the low-density, low-viscosity calcite melt. The extracted calcite melt mixed with the surrounding mafic melt. This resulted in crystallization of olivine with CaO contents up to 1.67 wt %. A local decrease in the silica concentration stabilized CaAl2SiO6-rich clinopyroxene. Brucite/periclase-free forsterite-spinel skarns probably originated by crystallization from the mafic melt close to the xenoliths at elevated fO(2). The high fO(2) was caused by CO2-rich fluids released during the decomposition of the xenoliths. The above case study provides the first evidence for partial melting of dolomite xenoliths during incorporation by a mafic magma.