Volcanism as an Agent of Formation of the Earth's Crust

  1. Leon Knopoff,
  2. Charles L. Drake and
  3. Pembroke J. Hart
  1. E. K. Markhinin

Published Online: 18 MAR 2013

DOI: 10.1029/GM012p0413

The Crust and Upper Mantle of the Pacific Area

The Crust and Upper Mantle of the Pacific Area

How to Cite

Markhinin, E. K. (2012) Volcanism as an Agent of Formation of the Earth's Crust, in The Crust and Upper Mantle of the Pacific Area (eds L. Knopoff, C. L. Drake and P. J. Hart), American Geophysical Union, Washington, D. C.. doi: 10.1029/GM012p0413

Author Information

  1. Volcanological Institute, Petropavlovsk-Kamchatsky, USSR

Publication History

  1. Published Online: 18 MAR 2013
  2. Published Print: 20 APR 2012

Book Series:

  1. Geophysical Monograph Series

Book Series Editors:

  1. Waldo E. Smith

ISBN Information

Print ISBN: 9780875900124

Online ISBN: 9781118663738



  • Earth's crust;
  • Juvenile water;
  • Kuril island arc;
  • Kuril ridge;
  • South Okhotsk basin;
  • Volcanism


The Kuril island arc is a surface expression of a structure extending downward into the mantle for several hundreds of kilometers. The main inclined shearing ‘surface,' the basic feature of the structure, has vertically branching feeding faults through which magmatic melts ascend to the surface. The entire observable geological sequence of the Kuril Islands, from Upper Cretaceous to Recent deposits, consists either of volcanic material or of the products of its reworking. About 6.5×106 km3 of silicate products (mostly pyroclastic) was ejected by the volcanoes from the beginning of the Cretaceous to the present; this volume is certainly sufficient to transform an oceanic crust into a crust of continental type. The average composition of the ejected material corresponds to andesite with SiO2 content up to 58%. The clarkes of chemical elements in the volcanic rocks of the Kuril Islands stand close to the clarkes of a continental crust. The share of the material assimilated by the subcrustal mantle from the previously formed layers of the crust constitutes a few tenths of a percent, or a few percent, of the total mass of eruption products. During the interval from the Upper Cretaceous to the present, volcanic eruptions alone have brought to the surface of the earth in the area of the Kuril Islands a mass of water vapor and other gas components of about 4×1014 tons. The mass of juvenile water ejected during this period by solfataras and hydrosolfataras is approximately the same order. The Kuril island arc, one of many present island arcs, is an analogue of old geosynclinal structures. Throughout geologic history, the entire continental crust, as well as the greater mass of the hydrosphere and atmosphere, could have been formed by products of volcanism of island arcs and related structures.