Pplates – Interactive plate tectonic reconstruction tool

Joe Kurtz and Gordon Lister

Research School of Earth Sciences, Australian National University, Canberra, ACT 0200, Australia

Pplates is a MacIntosh-based reconstruction program that aids in plate and continental tectonic reconstructions by providing a tool for visualisation of movements of continents and plates. Starting in late 2005, intensive development of Pplates focused on creating a version that will allow a user to deform plate crust while conserving crustal mass and isostasy. The official beta release occurred in April 2006 and included this capability.

New capabilities include the facility for users to:

(1) Create and save the history of a deforming continent reconstruction. Playback the history to the screen or to a PDF file.

(2) View strain induced in mesh faces (as strain eigenvectors) when a continent is deformed during a reconstruction (see Figure 1 )

(3) Turn on a spring model (elastic) rheology for a mesh and allow it to relax after stress-inducing a deformation. This allows the spreading of deformation phenomenologically. Other rheology models will be added.

(4) Incorporate the use of submeshes in the reconstruction process. Once a mesh has been established, some areas of the mesh may be designated as a submesh and moved as a unit within the mesh. This makes possible the designation of an area of a continent as rigid relative to the rest of the continental crust -- a craton, for example. The areas between cratons within a mesh are then representative of basins/orogens which can deform as cratons move relative to one another.

(5) Add decorations. A decoration is any file of latitude/longitude points (with other properties) which is display as symbols (mines, for example) or connected points (e.g. boundaries).

(6) Change color and appearance of mesh and decoration lines and symbols. These changes are saved when the mesh or decoration are saved.