Palaeogeography

Palaeogeography is the study of the historical geography of the Earth’s surface during past geologic times, focusing on the arrangements and distributions of land, seas, coastlines, and biogeographic patterns. It seeks to reconstruct past landscapes and assess how tectonics, sea level change, climate, and biology have shaped the position and connections of continents and oceans through time.

Reconstructing palaeogeography relies on multiple lines of evidence, including stratigraphy, fossil distributions, sedimentology, paleomagnetism, and isotopic data. Radiometric dating places events in time, while fossil assemblages and facies indicate past connections or separations among regions and the presence of shallow or deep seas, deserts, or forested environments. Paleomagnetic data reveal latitudinal positions and the historical orientation of continents, helping to place landmasses on ancient coordinates. Reconstructions are often presented as time slices or paleogeographic maps spanning Precambrian to Cenozoic intervals.

Plate tectonics is central to palaeogeography, as continental drift and orogeny reorganize landmasses and basins. Large-scale reorganizations, such as the assembly and breakup of supercontinents like Rodinia, Pangaea, and Gondwana, are key events that palaeogeographers quantify to explain shifts in climate belts, sea level, and biogeographic patterns. Sea level fluctuations drive transgressions and regressions that alter coastal landscapes and sedimentary environments.

Applications include understanding the historical distribution of organisms, climate change over deep time, and resource exploration through the targeting of ancient basins and depositional environments. Limitations arise from an incomplete rock record and dating uncertainties, which affect resolution and interpretation.