INFORMATICS BASED DISCOVERY AND INTEGRATION OF DATA TOWARDS UNDERSTANDING THE FATE OF PALEO-LITHOSPHERES FOR EASTERN NORTH AMERICA

The present day geometry of the crust and subjacent mantle for the Appalachian Geologic Province is considered to be the result of assembly and dispersal of two successive supercontinents. Regional seismic studies show a clear structural shallowing to the east of the sub-cratonal mantle, as well as rooting of all crustal lithologies (terranes) above the MOHO. Radiometric ages from igneous and metamorphic rocks provide a robust crustal event chronology that can be related to accretionary tectonics associated with episodes of terrane suturing. However, the observed geologic events seem to be grossly dissimilar to ages of the subjacent cratonal lithosphere mantle (SCLM) .The age of the SCLM, based on lead isotope modeling of Mesozoic (post-accretionary samples of the SCLM) and Cambrian basalts (pre-accretionary sampling of the SCLM), 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? A new continental scale tectonic model able to explain this physical decoupling of the complex crustal column with the SCLM is related to the geodynamic interaction of plates, where one of the plate margins contains well developed depocenters. Following recent discoveries in the Canadian Cordillera of decoupled terranes from their deep crust and mantle (Snyder.et.al. 2002), it is proposed that interaction of accreting terranes against depocenters also removed their SCLM as well. The model provides a possible explanation for the presence of only Grenville age mantle lithosphere under the complex collage of terranes observed at the surface. The consequences of such an age discontinuity between the crustal column and the SCLM has significant impact on interpreting EarthScope data, and requires the use of new geoinformatics technologies to further understand the temporal relationship between crust and mantle. It is clear that access to a broad spectrum of geosciences databases (seismic, geochronologic, sedimentologic, petrologic, structural and geologic maps) is a requirement for testing such a hypothesis. Developing a cyberinfrastructure that facilitates both discovery and integration of diverse disciplinary data would accelerate a more robust understanding of continental growth.