The Olmecs, aka the earliest known major civilization in Mexico following a progressive development in Soconusco. They lived in the tropical lowlands of south central Mexico
Rock layers in order is basically natures calendar.
The highest layer is the newest formed layer
While the deepest layer was the oldest and probably has been there from some time
And everything in between goes accordingly
So putting rocks in order by age helps scientists better understand what was there before what and how the rocks changed over time.
Hope this helps!
Brailiest is always appreciated if you feel its deserved! :)
Answer:
I am confused on what this is supposed to be, but if you are talking about chemicals, then your answer is sulfur.
Hoped this is what you're looking for. Sorry if it isn't. I would love to help, but it needs to be more specific.