Question

question 4 (20 points)
listen
spreading centers are an ideal location for volcanism because _.
the asthenosphere rock has low percentages of sio2
the oceanic plates pull apart causing hot asthenosphere rock to rise and undergo decompression melting to form magma that continues to rise
all of these
they sit above the high - temperature asthenosphere
question 5 (20 points)

Explanation:

Spreading centers are areas where tectonic plates move apart. The asthenosphere rock is hot and when the plates separate, the rock rises and undergoes decompression melting to form magma, which is a key factor for volcanism. Also, spreading - centers are located above the asthenosphere which is at high temperature. The percentage of SiO2 in asthenosphere rock is not the main reason for volcanism at spreading centers.

Answer:

B. the oceanic plates pull apart causing hot asthenosphere rock to rise and undergo decompression melting to form magma that continues to rise