Dr. Vladimir Davydov, Dr. James Crowley, and Dr. Mark Schmitz report the results of new geochronology in Pennsylvanian cyclothem deposits of the Donets basin (Ukraine) in an article recently published in Geochemistry Geophysics Geosystems, the electronic journal of the American Geophysical Union and the Geochemical Society. Ages for numerous coal-hosted volcanic ashes (tonsteins) demonstrate conclusively that cyclic sedimentation resulted from glacioeustasy forced by orbital eccentricity variations during the Late Paleozoic Ice Age. This work represents one product of a multi-disciplinary study to understand the growth and demise of the LPIA, funded by the National Science Foundation (EAR-0545247).