Question

how does the internal process starts in the earth’s crust

Answer 1

$\huge\bf{Answer:-}$

Refer the attachment.

Answer 2

Answer:

Earth's mantle and crust formed about 100 million years after the formation of the planet, about 4.6 billion years ago. At first the crust was very thin, and was probably changed often as the tectonic plates shifted around a lot more than they do now. Earth’s crust is divided into two types-- oceanic crust and continental crust.