From where the ores in the earth’s crust have come?

The ores in the earth’s crust have come from frequent volcanic eruption. A natural disaster is defined as a hazard which occurs naturally, that is a disaster that is not brought about by acts of human beings. A natural disaster might be caused by earthquakes, flooding, volcanic eruption, landslide etc. In order to be classified as a disaster it will have profound environmental effect or human loss and frequently incurs financial loss.