Vendian-cambrian of western Gondwana: Introduction / Венд-кембрийские отложения западной Гондваны: Введение

Gondwana (Suess, 1875) formed as a result of the Pan African-Brasiliano orogenies, and survived until the opening of the Atlantic in late Mesozoic times. For researchers dealing with the genesis of this remarkable supercontinent, the time period represented by the Vendian to Cambrian (ca. 600-500 Ma) is crucial. The Vendian to Early Cambrian was a period of outstanding events in Earth history, namely:

(1) Occurrence of the latest (near) global glaciation on Earth (Varangerian/Marinoan);

(2) Termination of a ca. 200 Ma-long period of global or near-global glaciations (Cryogenian);

(3) Climax of one of the most intense orogenic periods (Pan African-Brasiliano), leading to the amalgamation of the Gondwana supercontinent (Unrug, 1996, Fig. 1);

(4) Important changes in the chemistry of oceans and atmosphere;

(5) Advent and demise of the Vendobionta (Seilacher, 1992);

(6)  Occurrence of the oldest known mass extinctions, which might have been caused by a bolide impact (Grey etal., 2003);

(7)  The advent and diversification of metazoans and skeletons ("Cambrian explosion");

(8) Biological innovations related to sediment recycling and biomat grazing by metazoans, leading to the "agronomic revolution" sertsu Seilacher (1996); <...>