BHS shown at chronostratigraphic division of series from the Base of Pleistocene to the Base of Lower Cretaceous ( a– h) reconstructed paleogeographically with a global Mesozoic-Cenozoic plate motion model tied to a reference frame of Indo-Atlantic hotspots and placed into a plate tectonic configuration corresponding to the base of each series. Hiatus chronostratigraphy dynamic topography geological maps global geodynamics mantle convection.īase Hiatus Surface (BHS) obtained by expanding the Geological Hiatus Maps (GHMs) (figure 4) in fully normalized spherical harmonics (SH) and convolving with a Gaussian taper starting at degree 15 (compare with figure 5). Additional geological constraints together with interregional geological maps at the resolution of stages (1-2 Myrs), are needed to assist in future geodynamic interpretations of interregional geologic hiatus. Our results imply that different timescales for convection and topography in convective support must be an integral component of time-dependent geodynamic Earth models, consistent with the presence of a weaker upper mantle relative to the lower mantle. This is smaller than the mantle transit time, which, as the timescale of convection, is about 100-200 Myrs. We find significant differences in the distribution of hiatus across and between continents at the timescale of geologic series, that is ten to a few tens of millions of years (Myrs). We assume that interregional patterns of hiatus surfaces are proxy records of continent-scale mantle-induced vertical motion of the lithosphere. We extract hiatus information from these paleogeological maps, which we plot in a paleogeographical reference frame to link the maps to the plate and plume modes of mantle convection. Here, we use such maps to visualize major conformable and unconformable contacts at interregional scales and at the level of geologic series from the Upper Jurassic onward across North and South America, Europe, Africa and Australia. Interregional geological maps hold important information for geodynamic models.
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