You can get these resources by buying the Research Facility for coins in the Shop (available from lvl 10). There you can create iron ore, coal, ice, clay, quartz, stones, trees and bushes.

Most expedition lands (all lands except the one where your farm is) have a resource menu that shows how much quartz, iron, clay, and coal can be found in the location. The resource menu icon is located in the lower left corner of the screen. If you open it and tap on a resource, the game will immediately transport you to one of its deposits!