If the mountain was in the Front Ranges of the Rockies, I would look for a thrust fault underlying the mountain since thrusting is a low angle fault which juxtaposes older rocks on top of younger and thickens up the stratigraphic sequence. Also, mountains can form from normal faults whereby the hangingwall of the fault or the side of the fault which is towards the inclination of the fault drops down relative to the footwall (the side under the fault) so I would also look for a normal fault bounding a cliff face of the mountain.,
I would go on on the first option, population, community, ecosystem. If there is a control on the rapid growth of population, surely, pollution in the whole community will be reduced thus, making the ecosystem well balanced.
