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Palaeogeography provides the spatial context for understanding the evolution of the Earth System and the processes acting upon its surface. As such it plays an integral role in my research. Although my interest in palaeogeography dates back to my time working for BP in Sunbury, it was during the following 8 years as a graduate working with Fred Ziegler, David Rowley and Mike Hulver (as part of the Paleogeographic Atlas Project, The University of Chicago), that I was taught to appreciate the science behind the reconstruction of palaeotopography and palaeobathymetry. That it is more than simply moving continents and then drawing palaeo-shorelines or opening up Adobe Photoshop, although these do have their uses.
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LEFT: An orthographic view of the Maastrichtian (modified and augmented from that of the Paleogeographic Atlas Project) showing the distribution of Maastrichtian crocodilians (red circles) and dinosaurs (orange squares). Part of a more comprehensive dataset of Cretaceous-Recent palaeogeographies, sedimentological and ecological information manipulated in GIS.
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A set of geographies to complement the vertebrate data presented in my PhD were not finished in time for inclusion in the Thesis, but were completed during my postdoc at Reading (Markwick et al., 2000). These were then digitized into ArcInfo (ESRI). However, these original maps were quite basic and consquently an updated version was begun, with better constrained basemaps and an effort to reconstruct the palaeobathymetry. These methods are included in Markwick and Valdes (2004). The Maastrichtian, Early Eocene, Oligocene, and Late Miocene palaeogeographies have already been used by Dr Paul Valdes as boundary conditions for model runs using the UGAMP and UKMO GCM's, whilst other maps have been used by numerous other workers for plotting their own data.
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| RIGHT: The distribution of Early Eocene fossil crocodilians (red cricles) using the basic palaeogeographies, to which have now been robust bathymetries.
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My most recent study concentrated on the Maastrichtian palaeogeography, and the need for better constrained drainage systems as a boundary condition for coupled ocean-atmosphere modelling (due to the effect of freshwater on ocean salinity and therefore density and circulation). A full description of the method used is in preparation and once published will be added to this site.
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