The Earth relieves its stresses in many ways. Tensile stresses can result in roughly parallel splits (faults) in the crust, which allow the blocks between the faults (grabens) to sink. This leaves neighbouring blocks (horsts) standing proud. Too proud, sometimes; but geology is a great leveller. . . given time.
Said the horst unto the graben, “Well, I see you know your place,
It’s too bad I must rub shoulders with your kind.
Though one cannot help one’s origins, you’ve sunk so very low;
It’s one’s pedigree that counts, I think you’ll find.”
Said the graben to the horst, “Don’t you lord it over me, mate;
Your condition’s just an accident of earth.
I’m as upper-crust as you are; and eventually you’ll see, mate,
That erosion will restore our equal worth.”