Does every rock go through the complete rock cycle?
1 Answer
Feb 20, 2016
No, not really.
Explanation:
Oceanic basalts are the most likely to go through a complete cycle of formation, sea-floor spreading and then re-subduction back into the mantle.
But for example, higher crustal rocks like granite are lower in density than basalts so they often do not get subjected. They often end up as part of continental pre-Cambrian shield regions that sort of float along the top of the crust for billions of years (eg. the Indian Shield that underlies much of central India). However, some granitic mountains do get weathered down eventually and join the rock cycle as sediments deposited in basins. Eventually, these mountain ranges become pre-cumbrian shield regions - fairly flat.
