Garnet Pyroxenite and Eclogite Xenolites from the Sullivan Buttes Latite, Chino Valley, Arizona

  1. F.R. Boyd and
  2. Henry O.A. Meyer
  1. Daniel J. Schulze and
  2. Herwart Helmstaedt

Published Online: 19 MAR 2013

DOI: 10.1029/SP016p0318

The Mantle Sample: Inclusion in Kimberlites and Other Volcanics

The Mantle Sample: Inclusion in Kimberlites and Other Volcanics

How to Cite

Schulze, D. J. and Helmstaedt, H. (1979) Garnet Pyroxenite and Eclogite Xenolites from the Sullivan Buttes Latite, Chino Valley, Arizona, in The Mantle Sample: Inclusion in Kimberlites and Other Volcanics (eds F.R. Boyd and H. O.A. Meyer), American Geophysical Union, Washington, D.C.. doi: 10.1029/SP016p0318

Author Information

  1. Department of Geological Sciences, Queen's University, Kingston, Ontario, Canada

Publication History

  1. Published Online: 19 MAR 2013
  2. Published Print: 1 JAN 1979

ISBN Information

Print ISBN: 9780875902135

Online ISBN: 9781118664858

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Keywords:

  • Garnet pyroxenites;
  • Host rocks;
  • Mineral chemistry;
  • Petrography;
  • Sullivan Buttes latite;
  • Whole rock chemistry

Summary

An unusual suite of ultramafic xenoliths from Tertiary latites in Chino Valley near Prescott, Arizona, is comprised of garnet pyroxenites and eclogites and represents the first occurrence of eclogite xenoliths in non-kimberlitic rocks on the Colorado plateau. The mineral assemblage of the garnet pyroxenites (calcic clinopyroxene, orthopyroxene, garnet, and Fe-Ti oxide) is the product of a complex subsolidus reequilibration of three aluminous pyroxenes involving exsolution of garnet and an Fe-Ti oxide, deformation, and recrystallization. Unmixing of sub-calcic clinopyroxene, originally coexisting with calcic clinopyroxene and orthopyroxene, resulted in a lamellar intergrowth of orthopyroxene and calcic clinopyroxene. Eclogites (omphacite, garnet) have reacted with the host magma and may show evidence of partial melting. The absence of metamorphic eclogite xenoliths in basaltic rocks in the southwestern United States does not prove that eclogites are absent at depth. Basaltic magmas were probably too hot to preserve the relatively low-temperature eclogite assemblages.