Geoscience studies produce data from various observations, experiments, and simulations at an enormous rate. With proliferation of applications and data formats, the geoscience research community faces many challenges in effectively managing and sharing resources and in efficiently integrating and analyzing the data. In this paper, we discuss how this challenge is being addressed by the GEON Portal, a Web based distributed resource management system that provides integrated access to data and tools needed for knowledge discovery in the geosciences. Unlike previous data management efforts that were either data-driven or application-driven, the GEON Portal provides facilities for efficient sharing, discovery and integration of both data and services that use geoscience data. We identify the challenges involved in managing geoscientific resources and provide solutions that exploit the syntactic, semantic, temporal and spatial metadata associated with the resources. One of our goals is to provide some insight into the challenges involved in providing a comprehensive scientific data management solution based on our experiences with geoscientific data.