To summarize what have you learned, answer the following. Fill in the blanks to complete the sentence. Choose from the words in the box below.
The (1)
is made up of different kinds of rocks like igneous, sedimentary and metamorphic. Its thickness varies depending on its location:
thickest in the (2)
and thinnest along the
(3) It has an approximate thickness ranging from 5 to 50
km and has average density of (4).
The continental crust is composed mostly of (5).
that's why
it is less dense as compared to oceanic crust. The oceanic crust consists primarily of volcanic lava rock called (6) making it denser as compared to
continental crust. (7)
denser and heavier than the (8)
plates. Oceanic crust is (9).
the oldest age for this type is around (10)
compared to the four-billion-year old continental crust.
Crust
mountain regions
granite
Ocean floor
granitic rocks
basalt
2.8 g/cm³
Basaltic rocks
200 million years old
younger
of the ocean plates are much
of the continental
than the continental crust as