1Discernible layers in a transparent material that differ from the surrounding material in density or composition.

1. 1.1Geology Irregular streaks or masses in igneous rock that differ from the surrounding rock in texture or composition.
   Example sentencesExamples

   • The age pattern of cordierite leucogranites is neatly bimodal, with a population centred exactly on the same value as the schlieren and nebulitic mesocratic migmatites.
   • Petrography shows that the minerals in the enclaves, those in the schlieren layering, and also those forming the magmatic foliation do not show any signs of deformation or recrystallization.
   • The oldest age pattern corresponds to schlieren and nebulitic migmatites and is obviously bimodal.
   • These migmatites may be divided into three facies on the basis of their mesoscopic structures: schlieren, nebulitic and transitional.
   • Rare mafic enclaves, which include both xenoliths of country rock and magma pods more mafic than the host monzogranite, as well as schlieren, are parallel to this compositional banding.