Seriation is a relative dating method in which assemblages or artifacts from numerous sites, in the same culture, are placed in chronological order. Seriation has a rich history in archeology. Petrie (1899) was the first to use seriation as a formal method. He applied it to find a chronological order for graves discovered in the Nile area given objects found there.
You should read the Wikipedia article for a detailed explanation of seriation in archaeology. Here's just the technical part, with some hints at using the
R seriation package for seriation and generation of plots.
The simplest form of seriation is when your data are just presence/absence information, e.g. presence of a particular artifact inside a tomb burial.