The definition of acidic lava is molten material flowing from a volcanic vent. Characteristics of acidic lava is that it is viscous, high in silicates (minerals) and doesn't flow very far. The lava that is more common flows very quickly and does not have as thick of a texture and acidic lava is usually associated with composite cone volcanoes and the basic lava is usually associated with shield volcanoes.
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.