Dynamics of metasomatic transformation of the rocks of the lithospheric mantle and Earth’s crust in deep-fault zones controlling the Siberian platform trap magmatism

V. N. Sharapov, M. P. Mazurov, K. Chudnenko, K. E. Sorokin

Research output: Contribution to journalArticlepeer-review

Abstract

For a multirate approximation, we have determined the dynamics of rock heating by a magmatic-fluid flow in a flat permeable zone cutting the cratonic lithosphere of the Siberian Platform from a magma chamber at a depth of 50 km to the Earth’s surface. This dynamics is compared with the dynamics of infiltration metasomatism in a three-layer lithosphere section: (1) harzburgitic mantle (depth 50–40 km), (2) crystalline basement (39–7 km), whose composition was simulated by the section of rocks hosting the skarn deposits of the Aldan Shield, and (3) platform cover (6–0 km), with its simplified rock compositions specified on the basis of the rock compositions in the southern and northern parts of the trap area of the Siberian Platform. Numerical modeling of the metasomatic transformation of rocks was performed in a multireservoir flow reactor, using the Selektor software. The initial composition of fluids in a magmatic source varied from highly reduced (water–methane) to ordinary (water–acid) (lg pO2 from –13.0 to –12.0). The obtained balances of the interacting phases show no significant change in the mass of aluminosilicate rocks in the mantle and Earth’s crust sections and a significant loss of their mass under replacement of carbonate and sulfate deposits.

Original languageEnglish
Pages (from-to)833-844
Number of pages12
JournalRussian Geology and Geophysics
Volume60
Issue number8
DOIs
Publication statusPublished - Aug 2019

Keywords

  • Fluids
  • Infiltration metasomatism
  • Modeling
  • Siberian platform
  • Traps

Cite this