Silurian paleogeography in the framework of global plate tectonics

This paper discusses the paleogeography and plate tectonics of the Silurian using five global and twelve regional scale maps. These maps illustrate the distribution of major tectonic elements such as subduction zones, spreading centres, transform faults and main volcanic areas 435 and 425 Ma ago. The regional maps show the global paleogeographic configuration combined with palaeoenvironmental and palaeolithofacies distribution. The paleogeographic analysis shows that the continents of Gondwana, Laurentia, Laurussia, Siberia, South China and North China were separated by the Iapetus, Rheic, Paleoasian (Prototethys), Paleotethys, Panthalassa and Mongol-Okhotsk oceans. Spreading of the Rheic and Paleotethys oceans constituted the main Silurian extensional event. The Scythian-Turan-South Kazakhstan-Junggar-Tarim-North China chain of continents moved northwestwards, and this led to a gradual narrowing of the Paleoasian Ocean. The Caledonian-Scandian orogeny that resulted from the collision of Baltica, Avalonia and Laurentia constituted the main convergent event during Silurian times.