This phenomenon is so simple I feel like an idiot trying to describe it but I want to know the name of the process so I can search for a video to understand it better.
Observations: Geologists measure the age of the earth by studying the layers of the earth’s crust. Archeologists dig down and find remnants of the past under layers of dirt.
Assumptions: There are younger layers of dirt on top of the earth’s crust and older layers underneath. This seems like a continuous natural cycle of creation of a new top layer of crust.
Question: Where does all the dirt that becomes the next layer of sediment come from? Where is this perpetual supply of new dirt coming from?
It’s not like there is an endless supply of dirt stored in the sky and it’s constantly falling.
Do winds lift layers of dirt from one area of the earth and drop that dirt in another? That would just be a dirt exchange where one area wouldn’t have new layers of crust and another area would. That doesn’t seem correct with how ubiquitous the concept of layers of crust is.
Is it volcanoes that shoot dirt from the earth’s mantle into the sky then it slowly settles on the ground creating the next layer? If so that would mean the oldest layers of the crust at the bottom become liquified then are expelled into the air and settle as the newest layer of crust in the “dirt cycle” of crust formation. This would make crust creation continuous so it’s plausible but doesn’t feel completely correct.
In: 4
A late part of the answer is continental drift. Earth comprises multiple large tectonic plates that move relative to each other.
The Indian plate moves toward the Eurasian plate at a rate of 5cm/per year. This means an enormous amount of material needs to be displaced each year. The material is pushed up and the Himalayas are formed. The mountains are then eroded and deposit material in other locations.
Planrs can go below another plate like what happened once on the coast of South America. The crust will melt when it gets deep down enough and you get volcanoes. The Andes can be eroded away and deposit material over the eastern part of South America.
So parts of earth’s surface get new material on it while other parts are destroyed. It is a constant process on earth with material that move around
Latest Answers