Uh...we all know that Giant Cracks in the Earth's surface are caused by a mischievous Ice Age rodent trying to hide a nut....

OK, for those who haven't seen Ice Age...uh, do. It is fun.

Anyway--pictures of cracks like this are extremely useful for showing HOW things happen geologically. I used to tutor mineralogy...and always compared creation of minerals and rocks to cooking analogies. Worked very well. A matter of ingredient, pressure, temperature and time!