In the formation of gneiss from granite,the distinctive compositional bands form due to ____________.
A) crystals migrating within the rock
B) crystals dissolving, and atoms and ions migrating and reorganizing as new crystals
C) crystals melting, with new crystals solidifying in color bands
D) the bizarre and seemingly unknowable nature of the blueschist metamorphic facies

Question

In the formation of gneiss from granite,the distinctive compositional bands form due to ____________. 
A) crystals migrating within the rock 
B) crystals dissolving, and atoms and ions migrating and reorganizing as new crystals 
C) crystals melting, with new crystals solidifying in color bands 
D) the bizarre and seemingly unknowable nature of the blueschist metamorphic facies

Quizplus · Accepted Answer

The distinctive compositional bands in gneiss form due to the rearrangement of atoms and ions within the rock as it undergoes metamorphism, resulting in the formation of new minerals and the segregation of different compositions into distinct layers. This process does not involve melting or crystal migration, but rather the dissolution and reorganization of minerals within the original rock. Thus, choice B is the best answer. Choices A, C, and D are incorrect because they do not accurately describe the process of gneiss formation.

In the Formation of Gneiss from Granite,the Distinctive Compositional Bands