Can anybody tell if how deep or maybe how far does dirt go?

Question

Can anybody tell if how deep or maybe how far does dirt go?

Answer 1

Depends where you are and how much  is included in " dirt "  if you mean soil in its' loose description and natural state assume 600 mm then into soil/ clay mix 600 mm then into soft clay then into heavy clay then into rock or sandstone . Obviously the closer to rock the less soil and possibly no clay so depends , your local geology department would have several cross sections of you area . what do you want to do .

Answer 2

Earth is made up of several layers. Its skin, the crust, extends to a depth of about 40 kilometers (25 miles). Below the crust is the mantle area, which continues to roughly halfway to the center of Earth. The mantle is the thick layer of silicate rock surrounding the dense, iron-nickel core, and it is subdivided into the upper and lower mantle, extending to a depth of about 2,900 km (1,800 miles). The outer core is beneath that and extends to 5,150 km (3,200 mi) and the inner core to about 6,400 km (4,000 mi).