This is a little explored aspect within geosciences: the connection between the gravitational forces inside the Earth and the evolution of the landscape. Stony Brook University is leading a research project that focuses on the interaction between the evolution of the landscape, climate and the fossil record. In the new work, published in the journal Nature Communications, the researchers show using computer models that deep roots beneath mountain belts trigger dramatic movements along faults that result in mountain belt collapse and rock exposure. they were once about 24 km below the surface.
constantly evolving planet
Thus gravity, the reason we sit on Earth the way we do, and the reason it dominates space-time, is not only at the heart of the Earth’s silhouette, but is still there . shaping the planet from within.
The force of gravity causes movement along faults in the Earth’s crust, causing huge masses of rock to collapse at one point and exposing material elsewhere. This process creates so-called central metamorphic complexes.
Researchers have verified that these complexes are remnants of previously “collapsed” mountain ranges. Using computer models, they found that the main driving force behind the formation of these structures was the formation of layers and then the weakening of the bonds at their base.
As a result of the gravity of the impact, the heat, the movement of the mantle and the melting of the rocks, these structures break off and begin to collapse towards the interior of our planet. This causes the deformation of the earth’s surface, as well as the underlying layers.
The team studied core metamorphic complexes around Phoenix and Las Vegas in the US and confirmed that they appear to be remnants of previously collapsed mountain belts.
According to the scientists’ models, this extensional collapse is driven entirely by gravity pulling on different densities of material in the overlying crust and its mantle boundary.
“We show that gravitational body forces generated by crustal topography and root cause a ductile lower middle crustal upflow pattern , facilitated by a detachment surface evolving into a low-angle normal fault. This detachment surface detachment acquires large amounts of finite strain, consistent with the thick zones of mylonite found in central metamorphic complexes,” the authors explain.
The researchers believe their approach could help geologists understand other mountainous areas of the world, where crustal roots have thickened and partially collapsed. It could also change the way we understand Earth’s geological history and its possible future.
Referencia: Alireza Bahadori ., Holt, W.E., Austermann, J. et al. The role of gravitational body forces in the development of metamorphic core complexes. Nature Communications 13, 5646 (2022). https://doi.org/10.1038/s41467-022-33361-2