new crust comes from spreading center in sea floor spreading.
new crust comes from spreading center in sea floor spreading.
where does new crust come from in sea floor spreading?
spreading center
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pangea started to break up during the triassic ≈225ma. rifting affected regions which became the central atlantic (between north america and africa) and the gulf of mexico at about the same time. this rifting created a divergent plate margin that would play an integral role of the future geologic processes to follow. rifting which involves the stretching of pre-existing crust and mantle lithosphere was initiated by the existence of sufficient horizontal deviatoric tensional stress that broke the lithosphere. eventually rifting gave way to sea floor spreading in the atlantic and gulf of mexico in the mid jurassic, around ≈165 ma. sea floor spreading is where new oceanic lithosphere is being created by upwelling of material, unlike rifting where it only involved the stretching of the crust. convection currents in the sub-lithospheric mantle are the driving mechanisms that caused sea floor spreading to occur. new lithosphere is made when hot material beneath ocean ridges is brought to the surface by these cells. as the new lithosphere moves horizontally away from the ridges, the new crust added to the gulf of mexico and the atlantic caused the continents of north america and south america to be moved apart. seafloor spreading in the gulf of mexico ceased by the beginning of the cretaceous and spreading shifted to the proto-caribbean.
geology of the dallas–fort worth metroplex