The advent of satellite altimetry and the detailed ocean-floor topography derived from it in the 1990s led to the opportunity to test models of Gondwana reconstruction by going back to first principles using paleogeographic modelling software. While evidence may still be incomplete, this will always be the case. This is no excuse for not quantifying simple, defensible models that are driven by the 'photo-geology' of the ocean-floor and that can be tested against other data. At the same time, perhaps new ideas can help steer future investigations to where new data will be the most pertinent.

When the work started, at the height of the explosion in PC use, it was assumed that within a few years all tech-savvy earth scientists would be using paleo-reconstruction software routinely. Sadly, this still seems not to be the case and much of the literature evidently includes re-use of a body of possibly-erroneous earlier interpretations that are often in need of critical re-appraisal.

It is relatively easy to match two conjugate margins in isolation. As the work has evolved, the need to build the model holistically - across the whole of Gondwana - has become accepted as a necessary constraint on the validity of the model itself. It also gives a robust framework for testing past events in local areas where added complexity may exist. Very often 'blue sky thinking' still prevails in the community where global models should be providing some form of 'air traffic control'.

To bring new ideas to the attention of all those open to robust new thinking, a series of informal papers has been written with the aim of documenting progress quickly and sharing results with others as rapidly as possible. Some of the work has been written up and published formally but, of course, this process lags way behind what is being discussed actively with users from day to day. The following may therefore be seen as a series of discussion papers that invite comment, particularly from those with (preferably non-confidential) local knowledge and/or experience that can help confirm, deny or fine-tune the results. Generally speaking, the less recent papers are the most in need of revision. Some older papers have been totally superceded. But, best of all, join in the discussion!