Pegmatites,which occur in dikes,are unusual among shallow intrusive rocks in that they ____________.
A)possess porphyritic texture
B)possess exceptionally coarse grains
C)are mineralogically identical to the extrusive rock basalt
D)are glassy,cooling so rapidly that crystals do not have time to form

Question

Quizplus · Accepted Answer

Pegmatites are unusual among shallow intrusive rocks because they possess exceptionally coarse grains, often larger than 1 cm in size.

Pegmatites,which Occur in Dikes,are Unusual Among Shallow Intrusive Rocks in That