Note 121 — Chapter IV · The Microscopic and Optical Characters of Minerals. (continued 2)
Reading edition
Werveke’s (N. J. B., 1883, II, 97) theory is that a twin lamination may be caused by the forces producing mechanical deformations, as movement in the magma and mountain making pressure. Such lamellæ are characterized by the fact that their extent and course seem to depend on fracture lines in the crystal.