CYBERINFRASTRUCTURE FRAMEWORK AND 4-D EVOLUTION OF EASTERN NORTH AMERICA : FATE OF PALEO-LITHOSPHERES

The evolutionary history of the Appalachian Geologic Province (1200 Ma to present) has been studied for more than 200 years, including use of tools applicable for imaging the subjacent lithosphere and deeper mantle. The region preserves a complete geologic record of two successive supercontinent assemblies and dispersals, including evidence for rifting and development of passive margins, accretion of island arcs, ribbon continents, continental and oceanic blocks, as well as an events chronology related to each of these records. To extend the observed geologic events to lower crust and mantle lithosphere requires both geometric and temporal constraints for the evolution of the subjacent lithosphere. For example, geophysical imaging of the sub-crustal lithosphere shows a well defined structural shallowing to the east, but the age of that lithosphere, based on isotope modeling of Mesozoic basalts, has been estimated to be approximately 1 Ga. Where are the other subcrustal mantle lithospheres that must have been involved in the many accretionary events recognized by geologists, and what is the fate of such paleo-lithospheres? The multitude of data types required to estimate the mechanisms associated with 4-D assembly of the eastern North American lithosphere is too large for individual researchers to discover, and provides the most compelling need to deploy a web-based infrastructure to support discovery and integration of data. Cyberinfrastructure-oriented geologic research can utilize ontologies, a method of representing knowledge through a declarative formalism where geologic objects and phenomena have describable relationships between them. Through a community-accepted vocabulary of Earth science terms, ontologies provide an organizational structure for classifying data that can be discovered by computers. We require the creation of an ontologic framework for Earth science data with the express purpose of making it easy for individual geoscientists or even large agencies (1) to register their data through data level ontologies to facilitate discovery of the data, and (2) to query and integrate across multiple and diverse databases through disciplinary ontologies, thus leading to solutions of complex questions such as the fate of paleo-lithospheres.