Preface

Abstract

The Jurassic is a geologically very complicated period in Earth history, spanning from 200 to 145 Ma. The Pangean supercontinent and even the Gondwana-land broke up, and the violent circum Paleo-Pacific (Yanshan) orogeny and the collisions between Paleo-Pacific margins took place, both accompanied by extensive volcanism that may have been the cause of major environmental and biotic changes. With the rifting of the Pangea, North America drifted northwestward, narrowing the Pacific, and the North Atlantic opened, resulting in the formation of the Hispanic epicontinental seaway along the rifting area between North America, South America, and Africa and providing a corridor (Hispanic Corridor) for migration and exchange of biota between the Tethys and Paleo-Pacific. Sea-level was undergoing eustatic oscillations superimposed upon an overall significant sea-level rise from the Hettangian to the Tithonian in Europe and America. However, great regressions, especially during the Middle-Late Jurassic, occurred in middle and East Asia, and parts of North America, where the Jurassic terrestrial ecosystems were established. Atmospheric CO2 concentration during the Jurassic was high, and the climate got warm and humid, which resulted in the formation of large quantities of coal and oil, even in the high latitude areas. In par-ticular, latitudinal temperature gradients were increased during the Jurassic, and by the Late Jurassic the latitu-dinal influences became so pronounced that the animal world was segregated into the Tethyan, Boreal, and other faunal realms during the Late Jurassic. Such a separation of the world into different realms and the regressions in Asia on a large scale have caused the difficulties in establishing the GSSPs for Upper Jurassic stages and the base of Cretaceous, and also the problems in correlating the non-marine to marine Jurassic, including dating of non-marine Jurassic strata and geological events. In addition to major environmental changes, there were great biotic changes during the Jurassic including the major biodiversity variation represented by mass extinctions during the end-Triassic, Pliensbachian-Toarcian and end-Tithonian as well as the subsequent recovery of life in both marine and terrestrial ecosystems.