Structures and Formations Igneous Rocks - Geophotography
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Contact Zone

Contact Zone

Agmatite "A migmatite with the appearance of breccia" "migmatite (mig'-ma-tite)
A rock found in medium-grade to high-grade metamorphic areas, that is
pervasively inhomogeneous on a macroscopic scale, one part being pale colored and consistently of
quartzofeldspathic or feldspathic composition" (Ashworth, 1985, p.3). A composite rock composed of
igneous or igneous-appearing or metamorphic materials, which are generally distinguishable
megascopically (Dietrich, 1960, p.50). The term was introduced by Sederholm (1907, p.88-89). Cf:" Glossary of Geology, Fifth Edition