In Mirlyn Advanced Search, try searching for "geolog* map*" AND a geographic region to find maps for a particular area. Print maps can be filtered out by clicking on the "Limit to Available online" button above the search results.
EarthWorks allows you to search for vector and raster data across multiple institutions including Stanford, Harvard, Tufts, Columbia, Minnesota, UC Berkeley, and more. You will find public data, which may be downloaded from any of our institutions, as well as proprietary data held by a single institution. This project is in partnership with the OpenGeoportal project (opengeoportal.org) and is a customized instance of GeoBlacklight. You can read more about that here: http://opengeoportal.org/geoblacklight/.