At the present time a considerable number of types of projectile points, recognized as having respectable antiquity, are well known to the archaeologist. Among these are the Folsom, Sandia, Yuma, Gypsum Cave, Silver Lake, Pinto Basin, Lake Mohave, the Texas types, and others. Only relative ages can be given for most of these. What dates are possible are possible only in round numbers, as geological rather than dendrochronological evidence must be relied upon.
The ideal archaeological site would be one where all the above-mentioned types, together with all later types, serially down to the most recent one of modern times, were found stratigraphically laid down in their normal relations to each other, awaiting only the trowel of the archaeologist to relate them properly. It is safe to say that a site of this kind does not exist.