Palaeogeographic and geodynamic evolution of the Gondwana continental margins during the Cambrian

• Published in: Terra Nova
• Main Authors: Courjault‐Radé, Pierre, Debrenne, Françoise, Gandin, Anna
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 1992
• Subjects: Pacific; Antarc*; Antarctica
• Online Access: http://dx.doi.org/10.1111/j.1365-3121.1992.tb00615.x; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fj.1365-3121.1992.tb00615.x; https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1365-3121.1992.tb00615.x

SUMMARY During the Cambrian, two types of continental margins occurred around Gondwana. The eastern margin (Antarctica, Australia and southern South America) was characterized by a narrow continental shelf with a steep slope separating the shallow water environment from a deep‐oceanic one accompanied by mafidultramafic volcanics. The western margin was characterized by a wider continental shelf, probably passing gradually to an unknown outer basin. This comprised three main domains: the Asiatic shelf, composed of distinct cratonic blocks, presumably separated from each other by deeper‐water/ volcanic intracontinental basins; the European shelf, characterized by the development of shallow intracontinental siliciclastic basins; and the Americanc‐African shelf, morphologically and depositionally uniform. The distinction of these two Gondwana continental margins expresses their different geodynamic behaviour during Cambrian extensional tectonics. In fact, the sedimentary/palaeogeographic evolution, suggests the establishment of an active Pacific‐like margin in the eastern domain, and the tentative establishment of a divergent Atlantic‐like margin, in the westem one.