Earth is the result of gravity. We now call home a swollen sphere of mineral because of the amount of dust and rock that drew in.
Our planet is still being shaped by gravity in far more delicate ways than we might think. There are subtle effects deep-lying structures can have on the rise and fall of the crust above.
The researchers behind the study compared it to a mass of ice under the water, which isn't immediately visible, but which still has an important role to play in the structure and the shifts that occur higher up.
These deep pulls and pushes are able to create some dramatic movements along faults in Earth's crust, collapsing mountain belts and exposing rocks that had previously been as far away as 15 miles below the surface.
The conditions of their evolution remain something of a mystery, despite numerous studies trying to explain the mechanisms behind their formation. Key geological processes behind the formation of these complexes were identified by the researchers.
The team found remnants of collapsed mountain belts in Phoenix and Las Vegas.
The researchers used a computer model to show how the landscape had changed over time, and they found that the main driver of core formation was a change in the landscape's shape.
Under a mountain range, lighter crust forms where it intrudes into and replaces the heavy mantle. Weakened through processes including heat, fluid movement, and rock melt, these mountain footings can collapse.
The surface of the core complexes can be seen in a "domed upwarp" and can be seen in the rocks known as mylonites.
The researcher's models show that the collapse is caused by gravity tugging on different densities of material in the crust and mantle.
The research builds on two previous and related studies from the same team of researchers, showing how the region of the US Southwest may have looked before, during, and after the core complexes.
A study from the same group showed how deep Earth forces combine with climate to influence the landscape.
The new research could change the way we understand the history of Earth and predict how it will evolve in the future.
The researchers think that their modeling approach might help geologists understand other mountainous areas around the world, where the roots of the crust have fallen.
Many exposures of ancient gneissic domes around the world, where the brittle cover has likely been removed through erosion, are explained by the study findings.
The research has appeared in a journal.
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