The Earth After Us: What legacy will humans leave in the rocks?

What would alien visitors in the far future, piecing together the history of earth, find of our brief reign? What clues will we leave? What fossils? Just as we have gained knowledge of the past, of ancient climates and the activities of creatures long dead, so too might they decode the rocks. The Earth After Us takes a novel approach to show how geologists unravel the information in the rocks. As the alien scientists start investigating the strata, what story will they tell of us? What kind of fossils will humans leave behind? What will happen to cities, cars, and plastic cups? How thick a layer will the 'human stratum' be? And will it be obvious which species dominated the planet?