eli5 Why are historical/archaeology structures/evidence underground?

142 viewsOtherPlanetary Science

Earth as a whole is essentiallly a closed system right? Nothing leaves except what we send into space and (presumably) no material enters earth except the some space debris.
Where does all the earth/dirt come from to consistently bury historical structure under ground across the world?

In: Planetary Science

10 Answers

Anonymous 0 Comments

I think there’s three things.

1. If you demolish an old falling down building, you then cover over the top of the remaining debris to start your new building on a flat solid ground.
2. Everything is moving down-hill usually from wind and water. And in modern times, farmers ploughing fields. Most buildings are built down on flat land. Over long periods of time material from higher points are distributed over the lower land.
3. Dirt is being created from plant matter. If a tree grows, then dies, then decomposes, all those leaves that have fallen along with any parts of the dead tree will add a small amount of dirt which wasn’t there before. Basically the world is a composter.

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