How much time does it take to disappear the remnant of dead civilization?

There is a theory that states that people are not first species which build a civilization. Writer  Michael Cremo convinces that before homo sapiens on Earth were living another intelligent race. If on Earth, millions years before our civilzation were living another one, can we identify its leavings?

Earth age is around 4,5 billions years. Complex organisms appeard on its surface about 400 millions years ago.

So is it possible that we are not first? If on Earth, millions of tens of millions of years ago, creatures building factories and power plants lived, how to find their traces? This is not so easy, because after about 4 million years all identifiable remains of a fallen civilization would disappear. Moreover, if it existed earlier than 2.6 million years ago, we would only be able to follow its trail thanks to analyzes of deep layers of rock. 

What if one developed civilization can be ... a source of propulsion for another. The development of industry and the climate changes behind it contribute to the formation in the oceans of so-called dead zones. Dead organisms form sediments from which fossil fuels are developed over time, which are the industries of the next civilization.

Probably we are first, but who knows, maybe we are wrong?