WHAT IS THE CRUST OF THE EARTH AND HOW IS IT DISTINGUISHED FROM THE MANTLE AND THE CORE?
The crust, the top part of which includes the ground we walk on, is the hard, outer surface layer of the earth. Although the crust is about 6 to 30 miles deep, the scale (size) of [figure 2] allows it to be drawn only as the thin outer line. The rocks and minerals that we are all acquainted with are found in the crust. These rocks are not as dense and do not have as high an iron content as do the rocks of the mantle and the core.