PALAEOGEOLOGICAL HIATUS SURFACE MAPPING —A TOOL TO VISUALIZE INTERREGIONAL-SCALE VERTICAL MOTION OF THE CONTINENTS

Dynamic topography is a well-established consequence of global geodynamic models of mantle convection with horizontal dimensions of over 1000 km and amplitudes up to 2 km. Such physical models guide the interpretation of geological records on equally large dimensions. Therefore, continental-scale geological maps form the reference frame of choice to identify any long-wavelength, low amplitude vertical surface motion. The maps display interlocking patterns of conformable and unconformable time boundaries traceable over hundreds to thousands of kilometers at currently available resolution of geological systems or series; They contain information about shape, dimension, age and duration of hiatus in millions of years. To demonstrate the methods’ potential, palaeogeological hiatus surface maps are constructed for two basal series boundaries based on the 1:5 Million-scale International Geological Map of Europe (Asch 2003). As a single-step technique, it applies to any geological map to visualize hiatus and serves as a proxy for palaeotopography on interregional scales. Additional geological data are required to calibrate proxies and refine shapes. Palaeogeological hiatus surface areas must be mapped on continental scales before their meaning may be inferred based on physical mechanisms, e.g., the dynamic vertical motion of the earth surface. The tool magnifies the need to compile geological information on maps at the temporal resolution of stages, matching process rates. When applied to marine seismic sections that relate to rock record, not to time, biostratigraphic and radiometric data from deep wells must be available before hiatus maps — that relate to time — can be constructed.