The Azuara and Rubielos Structures, Spain: Twin Impact Craters or Alpine Thrust Systems? TEM Investigations on Deformed Quartz Disprove Shock Origin
Abstract
The origin of the Azuara structure, NE Spain, is controversially discussed. It is interpreted as either an impact crater or Alpine thrust system. Recently, it has been suggested that Azuara has a twin impact crater: Rubielos. TEM analyses on quartz grains from quarzites of the Azuara and Rubielos areas, which have been described to contain shock features, only reveal a large density of dislocations and many sub-grain boundaries; planar deformation features are absent. This result does not disprove an impact origin for Azuara and Rubielos; unambiguous signs of shock metamorphism,however, are not yet known from these regions.
- Publication:
-
Lunar and Planetary Science Conference
- Pub Date:
- March 1996
- Bibcode:
- 1996LPI....27..725L
- Keywords:
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- CRATERS: IMPACT;
- METAMORPHISM: SHOCK;
- MICROSCOPY: TRANSMISSION ELECTRON