Advanced Mines (CTP1)

is a tile improvement in Civilization: Call to Power.
==Gameplay==
Advanced mines use improved mining instruments to create additional +10-30 and +5-10 when worked. This improvement takes two turns to build and, depending on the terrain, costs 800-1000 PW.
==Great Library entry==
In the 19th century miners developed techniques to increase their rate of return while minimizing attendant dangers. Miners sprayed heavy water jets at hillsides to strip away layers of the earth. Miners used explosives such as TNT to dig though the solid granite of the earth's crust. Later advances included pumping superheated water into mineral beds to melt sulfur.