Is There a Human Civilization?

Human civilization currently only fills a small portion of earth's surface right now. And we only access tiny fraction s of earth's previous surface through through various kinds of drilling and uno access through exposure to rock strata. So that there's just like extreme selection of filters on both sides, on the deposition and on the excavation sidey it would be kind of like even if you knew somehow, with some certainty, that there was an ancient technological civilization during this time.