Metamorphism (the process called intrusion)
Answer:
Overexploitation of resources.
Explanation:
In this case it's overexploitation of natural resources, wich is a big problem nowadays. Using resources excessively results in damaged resources, that's called overexploitation.
The Mongols, a tribe of Nomads from Central or North Asia, who were ruled by Genghis Khan at the time.
