Metadata scheme harmonization and the development of 'generic' metadata standards have been proposed and studied as techniques to alleviate the problem of metadata integration. However, the use of existing upper onotologies as base models for metadata schemas provides an alternative that allows for a significant reuse of knowledge representations that have been evaluated and refined in the last years. In that direction, this paper explores the linking of Dublin Core terms to the OpenCyc knowledge base. The results of the integration point out that these upper ontologies are actually prepared for the representation of at least the base elements of current metadata schemas, and they could consequently be used as a core model. This approach would enable higher levels of metadata coherence and richer semantics, as long as the upper ontologies used are reasonably stable.