A Study of Optimal Twin Boundaries: Part A: Composition Planes of Pericline and Albite Twins and Slight Deviations Thereof. Part B: The Ideal Composition Planes of the Feldspar Twins, Parts 1-2 |
Common terms and phrases
0-lattice 0-plane abcosy accosẞ acline albite twin law angle of shear anorthite axes b-axis b-subspace normal Baveno Burgers vector c-centred calculated Carlsbad cc)-lattice cell walls coincide column vectors complex twins corresponding cosẞ COSX cosy described deviations dislocation network eigenvector equation feldspar twin feldspars given glide plane Hence High Albite ideal composition plane ideal pericline twin inverse matrix irrat lattice angle lattice constants lattice point Low Albite Manebach metric tensor Microcline monoclinic monoclinic feldspars O-elements O-lattice theory O-lines O-plane Observed Composition Plane obtain orientation orthogonal coordinate orthogonal coordinate system Parallel Twin PC PC pericline law pericline twin law plagioclases rank reciprocal lattice referring relating closest neighbours rhombic section Roc Tourné rotational axis shear transformation symmetry Table tion translation lattice translation vectors triclinic triplets twin elements twin junction twin plane unimodular matrix unit cell vector of lattice vector product X-Carlsbad X-pericline zone וכ