QUANTITATIVE GLOBAL PALEOGEOGRAPHY: INTEGRATING GEOLOGY AND GEODYNAMICS IN THE CREATION OF NEXT GENERATION PALEOGEOGRAPHIC MAPS

Paleogeographic mapping to date has largely been predicated on integrating geologic information with a certain artistic license in which modern analogs are used as templates for mapping ancient features. The cyberinfrastructural needs for such an endeavor are primarily focused on abstraction of data from a wide range of data sources, most of which never anticipated use in paleogeographic mapping, and are therefore not ideally structured for this purpose. We present a new quantitative approach to paleogeography integrating global digital elevation data together with global estimates of the magnitudes of vertical elevation change resulting from a range of processes, including, but not limited to, glacial isostatic adjustment (GIA), rigorously constrained mantle dynamics (dynamic topography=DT), crustal thickness changes related to tectonics (TC), erosion (E), and deposition (D), all of which are represented by their isostatically adjusted change in topography. The sum of the contributions of each of these components represents the change in topography as a function of space and time which when added to the present topography represents the retrodicted paleotopography. Different estimates of GIA and DT resulting from different viscosity models and/or different scalings of seismic velocity from global tomography to density can be used to establish an estimate of uncertainty on the resulting retrodictions. Retrodicted paleogeographies can then be compared with geologic data as explicit independent tests of the retrodictions and differences can be flagged in the resulting grids by assigning unique values to these grid cells. We present examples of such retrodicted paleogeographies. The cyberinfrastructural needs include geological data abstraction together with rigorously constrained estimates of GIA, DT, TC, E and D.