Virtual reconstruction of stratigraphy and past landscapes in the West Coast Fossil Park region

[摘要] The West Coast Fossil Park near Langebaanweg in the Western Cape, South Africa, is known forits abundance of marine, freshwater and terrestrial fossils of Mio-Pliocene age. The fossilbearing deposits reflect the complex and varied depositional environments, which wereinfluenced by the change in course of the Berg River and regressions and transgressions of sealevel.The fossil deposits at this site are world-renowned for their species richness anduniqueness and there was a need to gain an in-depth understanding of the events that gave rise tothis situation. To understand these complexities, it was necessary to construct a compositemodel of the pre-history of the West Coast Fossil Park, incorporating topological, geological andpalaeontological data. GIS provided the ideal platform to integrate data from such variedsources, using spatial correlation to interpret commonalities. Subsequently, a spatially explicitdatabase of the present-day study area, from Dwarskersbos in the north to just north ofYzerfontein in the south, was constructed. The oldest geological formation, the basement layer,as well as three successive formations was reconstructed on a regional scale using borehole data.Interpolation of point data to regional surfaces was a dual process incorporating expert opinionand purpose-built tools within ESRI's ArcInfo and ArcMap 8.3. A similar reconstruction at afiner scale was done for the West Coast Fossil Park area using kriging as an interpolationmethod. These reconstructed geological layers can be used to predict the depth and location offossil-bearing deposits. There is scope for further study and analysis to compare the accuracy ofalternative interpolation methods, and combining it with field-based validation of modelledoutputs.

[发布机构] Stellenbosch University