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Shock and thermal metamorphism of basalt by nuclear explosion, Nevada test site

January 1, 1969

Olivine trachybasalt metamorphosed by nuclear explosion is classified into categories of progressive metamorphism: (i) Weak. Plagioclase is microfractured, and augite cotainis fine twin lamellae. (ii) Moderate. Plagioclase is converted to glass, and mafic minerals show intragranular deformation (undulatory extinction, twin lamellae, and, possibly, deformation lamellae), but rock texture is preserved. (iii) Moderately strong. Plagioclase glass shows small-scale flow, mafic minerals are fractured and show intragranular deformation, and rocks contain tension fractures. (iv) Strong. Plagioclase glass is vesicular, augite is minutely fractured, and olivine is coarsely fragmented, shows mosaic extinction, distinctive lamellar structures, and is locally recrystallized. (v) Intense. Rocks are converted to inhomogeneous basaltic glass.

Citation Information

Publication Year 1969
Title Shock and thermal metamorphism of basalt by nuclear explosion, Nevada test site
DOI
Authors O.B. James
Publication Type Article
Publication Subtype Journal Article
Series Title Science
Series Number
Index ID 70011516
Record Source USGS Publications Warehouse
USGS Organization