Affordable Access

Publisher Website

Eclogites in the French Palaeozoic Orogen: geodynamic significance

Authors
Journal
Tectonophysics
0040-1951
Publisher
Elsevier
Publication Date
Volume
169
Issue
4
Identifiers
DOI: 10.1016/0040-1951(89)90094-2
Disciplines
  • Earth Science

Abstract

Abstract Eclogites are widespread in the Devonian internal zone of the French Palaeozoic Orogen. They occur in different tectonic settings, either in high-pressure-low temperature or in high-pressure-high-temperature environments. They are tectonically incorporated into several major allochthonous units, as demonstrated either by their blastomylonitic texture or by their being in evident disequilibrium with their country rocks. The protoliths of the presently well-identified eclogite-bearing series present different typical associations, depending on their present location. The igneous series include within-plate basalts, normal and transitional MORBs and even calc-alkaline rocks. They were erupted mostly during the Palaeozoic, although they sometimes contain inherited Precambrian zircons. Further, some of them may be remnants of old Precambrian oceanic crust. Most of the eclogitic parageneses were generated during the earliest Silurian tectonometamorphic climax, either in low-temperature or in high-temperature conditions. Later, they followed various retrograde courses in still geographically distinct low-temperature or high-temperature associations. The basic rocks in the Leptynolitic Amphibolitic Complex and particularly the eclogites, thus provide sufficiently clear evidence to support a new geodynamic scenario implying one or several subordinate narrow tensional zones in a thinned but well-developed continental crust rather than in a true oceanic domain.

There are no comments yet on this publication. Be the first to share your thoughts.