Geophisics - Blog Posts

Evidence prove the role of  collisions in the formation of earth

On going collisions of different sized rocks from small planets to smaller rocks was the beginning of the formation of our planet.  Scientists have discovered a vast structure made of dense material occupying the boundary between Earth’s liquid outer core and the lower mantle, a zone some 3,000 kilometers (1,864 miles) beneath our feet. They discovered  the presence of anomalies deep inside Earth called ultra low velocity zones (ULVZs), which are dense patches on the core-mantle boundary.  By running thousands of seismograms through Sequencer they found evidence of the existence of two “mega-ULVZs,” zones that stretch for about 1,000 kilometers, or more.  Mega-ULVZs are intriguing structures not only due to their size, but because they may be composed of exotic materials that date back to a time before Earth had a Moon. These huge anomalous chunks could be partially melted material that predate the Moon formation event, which scientists think was a gigantic collision between early Earth and a Mars-sized object more than four billion years ago.

But my point is if the core of the earth is formed through collisions why shouldn’t the crust be formed in the same way?

Source: https://www.vice.com/en/article/ep4zvw/scientists-have-discovered-vast-mysterious-structures-deep-inside-the-earth?utm_content=1603702277&utm_medium=social&utm_source=VICE_facebook