NAVDAT—A WESTERN NORTH AMERICAN VOLCANIC AND INTRUSIVE ROCK GEOCHEMICAL DATABASE

At present there is no generally accessible geochemical database for Mesozoic and younger volcanic rocks in North America, despite the proliferation of high quality age, chemical and isotopic studies of these rocks over the last 15-20 years. As a result, it is not currently possible to extract from the existing volcanic rock data the regional patterns in the age, compositions, and sources of western North American magmatism that would allow assessment of how volcanism relates to the overall Cenozoic geologic evolution of western North America. With support from the NSF-IT program and DOD-China Lake, we are initiating a two-year project to compile existing age, chemical, and isotopic data from Late Cretaceous to Holocene extrusive and intrusive igneous rocks from the western U.S., British Columbia, and northern Mexico into a web-accessible electronic database. The resultant product, the Western North America Volcanic and Intrusive Rock Database-NAVDAT, will be integrated into a geographic information system (GIS) to allow visualization of complex age-compositional patterns in volcanism throughout the study region. We will also develop any necessary relational and graphical tools to allow users of the database to address a wide variety of issues concerning the geologic evolution and present volcanic state of the western U.S. We anticipate that NAVDAT will yield fundamental insights into the role of changing plate orientations, mantle plumes, and lithospheric deformation in controlling the production, distribution, sources and composition of magmatism in the western U.S. and so provide a basis for general models of continental magmatism worldwide. The database will also provide a means of further investigating the origin of local volcanic centers in the western U.S. by allowing these centers to be rigorously assessed in terms of regional trends in the position, age and composition of magmatism. Finally, NAVDAT will provide the background database necessary for clearly identifying targets for additional studies of igneous rocks in the western U.S. and for archiving new data generated by these studies. Community input from both the data supply side and suggestions for features that would make NAVDAT useful to a broad community are most welcome.