How do archeaological sites become buried underground?

Question

Okay, I know one answer to my question already: Natural disasters like volcanic eruptions and floods destroyed and buried some sites. But how did other sites end up underground?

For instance, the old foundation walls of President Washington's house in Philadelphia appear to be about 10 to 15 feet below current street level. And that house was demolished less than 200 years ago. How did those ruins end up so far underground in that time frame? Did someone bury them? If so, then why isn't there a 15-foot hill on top of the ruin site? What are some other ways that sites become gradually buried?

Answer 1

These sites become buried by many different processes. In some, local habitations were at the margins of streams, lakes and the ocean. In time the shifting of deposition covers the sites.

In surburban sites, the rufuse of civilization piles up against existing sites and in time covers it completely. These sites are commonly called Tells in Asia.

In other sites, the existing buildings may go into disrepair and more modern building techinques or engineering practices cause them to be covered with grade material as the new level of construction is raised over the existing, lower level of older constructions.

Answer 2

answerer above me is right but also many people back then use to build on soft soil that's why many homes back then use to randomly collapse or sink. in fact in Pennsylvania even today they have to be careful where to build houses and businesses because sometime there or soft spots in the soil or a soft layer beneath the top layer which could also be a hazard. especially near water. think about it. people back then did not have irrigation like we do now so they used to live close to bodies of water. also naturally with global warming our water ways are widening so many sites are going to be submerged.