- Welcome to the U. S. and Canada Obsidian and FGV (Fine-Grained Volcanic Toolstone) Source Mapping Project home page. For many years, we’ve been chasing down obsidian and FGV sources in the western United States and have promised that someday - when enough source information was finally available - we would begin creating maps that illustrate the geographic patterning of these archaeologically-significant prehistoric sources of natural glass and volcanic toolstone. That day has finally come and we are currently in the process of assembling and producing source maps for the western United States and Canada. Along with a few states (and provinces) for which we still lack good GIS coverages or adequate source data, we’re currently working on regional maps that illustrate the spatial ranges of several geographically-extensive sources.
- Pleistocene (Wikipedia)
The Pleistocene (/ˈplaɪstəˌsiːn, -stoʊ-/ PLY-stə-seen, -stoh-; often referred to colloquially as the Ice Age) is the geological epoch that lasted from c. 2.58 million to 11,700 years ago, spanning the Earth’s most recent period of repeated glaciations. Before a change was finally confirmed in 2009 by the International Union of Geological Sciences, the cutoff of the Pleistocene and the preceding Pliocene was regarded as being 1.806 million years Before Present (BP). Publications from earlier years may use either definition of the period. The end of the Pleistocene corresponds with the end of the last glacial period and also with the end of the Paleolithic age used in archaeology. The name is a combination of Ancient Greek πλεῖστος (pleîstos), meaning “most”, and καινός (kainós; latinized as cænus), meaning “new”.