Answer: Varves, the meatloaf of the Earth
Explanation: Do you know meatloaf? Well, we know that a meatloaf is basically a set of meat layers, one on top of another.
Varves are the same, but these are formed by layers of glaciar or mineral grains. All positioned, just as meat loaf, one on top of another: In sense of ascending seasons.
Varves are useful for GEOCHRONOLOGY, cause they can determinate the absolute age of some rocks of glaciar origins.
At the center of the Earth is the core, which has two parts. The solid, inner core of iron has a radius of about 760 miles (about 1,220 km), according to NASA. It is surrounded by a liquid, outer core composed of a nickel-iron alloy. The outer core is about 1,355 miles (2,180 km) thick.