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Q. What are these maps?
Q. Why are there no rotated coastlines of grids?
Q. What format are these maps in?
Q. What is the source of the data used for these maps?
Q. How can I cite these maps?
Q. Are these maps available?
Q. When will the final Generation I maps be finished?
Q. You talk about Generation II maps. What do you mean?
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Q. What are these maps?
A. These maps are a series of Cretaceous - Recent maps that were originally compiled for use in my PhD thesis (Markwick, 1996). Unfortunately they were not completed until 1997 and my postdoc at the University of Reading (Markwick et al., 1999; 2000). They are based on a limited set of unfinished maps produced at the University of Chicago by the Paleogeographic Atlas Project for 13 time-slices throughout the Mesozoic and Cenozoic. I have added additional time-slices such that every stage of the Cretaceous and sub-epoch of the Cenozoic will be available (the aim for the next generation of maps will be for stage level maps of the Cenozoic as well). I had hoped to have had these ready for publication by now, but the demand of a full time job in Industry and other commitments have prevented this. Nonetheless the maps have been used by numerous researchers in both the US and UK. The final set of maps (Generation I) should be available shortly (I only show low resolution jpegs here of the 1997 drafts), which will look more like the Maastichtian map (Markwick et al., 2001; 2002; Markwick & Valdes, 2003 with completed palaeobathymetry, tectonics, palaeo-drainage, etc., (look at the bottom figure on the Palaeogeography page of this site)
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Q. Why are there no rotated coastlines or grids?
A. All of the data (rotated detailed modern coastlines, countries, provinces, rivers, and 1 degree grid) have been compiled in ArcGIS as both shapefiles and coverages. I haven't included them on some of the lower resolution maps, because doing so would make the figures (at this low resolution) very busy and obscure the geographies. They are shown on the polar projection images for each timeslice. However, care must be taken in looking at the details of these maps since the original compilations were made at a low resolution (on A3 maps) using only a very coarse coastline and 5 degree grid, which was all I had available at the time (see below). With the more detailed basemaps now available, a more precise series of geographies for general use is in preparation. For Industry applications, users should contact me directly at GETECH, where we have specific solutions and methodologies already established (pjm@getech.leeds.ac.uk).
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LEFT: An orthographic view showing the original low resolution coastline and 5 degree grid onto which were drawn the draft palaeogeographies shown throughout this site. The transition to ArcGIS has meant that the more detailed rotated data can be used at a variety of scale and the discrepancies caused by using this low resolution basemap remedied; this is ongoing work.
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Q. What format are these maps in?
A. All of my palaeogeographic, palaeoclimate and palaeoecological work is now done through GIS; specifically ESRI's ArcGIS and it's precursors ArcView 3.3 and ARC/INFO. These shapefiles and coverages are complemented by jpeg versions, some of which are available on this web site (click here).
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Q. What is the source of the data used for these maps?
A. The maps are compiled using data from my own databases of lithologic, tectonic and fossil information, the lithologic databases of the Paleogeographic Atlas Project (The University of Chicago), a survey of published literature, and DSDP / ODP data. Interpretations of elevation are derived following the methods outlined in Ziegler et al (1985), an understanding of the tectonic regime and evolution of each feature, and the age-depth relationship for the ocean. The latest Maastrichtian DEM work (Markwick and Valdes, 2004) also draws heavily on a study of modern drainage systems.
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ABOVE: Orthographic views showing the distribution of data used in the compilation of each map (see Markwick and Valdes, 2004, for further detail).
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Q. How can I cite these maps?
A. These maps have now been formerly published as part of a paper on climate proxies and data-model comparisons; details and a pdf of this paper (Markwick, 2007) can be found in the Publications section of this website.
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Q. Are these maps available?
A. A number of researchers have been using these maps since they were drawn in 1997. Students, researchers, etc., are welcome to download the images for research, although bare in mind the low resolution, which really does not do justice to the maps. Now that the maps have been published the shapefiles will be placed on this website shortly; I am currently working on revising the metadata for all files.
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Q. When will the final Generation I maps be finished?
A. Supposedly last December. So I guess I'm a little late! Watch this space.
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Q. You talk about Generation II maps. What do you mean?
A. The generation II maps take palaeogeography a step further since they'll have been compiled entirely in ArcGIS and therefore can be more properly attributed. The maps will also be completely be re-drawn based on a more detailed literature search, and a greatly modified set of plate rotations. Based on lessons learned from the Maastrichtian DEM and drainage work (Markwick et al., 2001, 2002) there will also be a more detailed treatment of palaeo-drainage. In truth, part of the delay in getting the Generation I maps submitted is that I've already started on the Generation II maps. A problem of knowing what can be done, trying to do it, but having to work around a full time (non-academic) job at the same time.
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