How Old is Backyard Dirt?

Did you know you can send Science questions to the New York times?

This person asked "How old is backyard dirt?" Read the whole response here!

You might read this section: "In contrast, areas farther south, which have never been covered by glaciers, have been experiencing the weathering of rocks into soil for millions of years... " and ask yourself "why would being covered by a glacier make the soil younger?" The answer is of course that glaciers are the biggest bad-est erode-rs! If you think about it giant heavy blocks of ice moving over the landscape are not going to leave very much in place. So pretty much every thing covered in Ice during the last glacial maximum (the last time glaciers were at their maximum extent about 20,000 years ago) started over / is covered with glacial till.