Abstract
Asymmetric aggregates of fine-grained leucoxene and quartz are reported from siliceous L-S tectonites deformed by progressive simple shear. The leucoxene fish, morphologically similar to mica fish, consistently yield shear senses in agreement with other kinematic criteria. We interpret the leucoxene as a pre-or early syntectonic alteration product of detrital heavy-minerals in a siliciclastic protolith. The leucoxene fish behave as passive markers, and they record kinematics by modification of pre-existing aggregates rather than syndeformational mineral growth. For siliceous metasedimentary rocks otherwise lacking in micro-kinematic indicators, leucoxene fish may provide an alternative to quartz c-axis analysis.
Original language | English (US) |
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Pages (from-to) | 1493-1497 |
Number of pages | 5 |
Journal | Journal of Structural Geology |
Volume | 18 |
Issue number | 12 |
DOIs | |
State | Published - Dec 1 1996 |