Deccan Traps
The Deccan Traps in the region of the Deccan in western India is one of the most marked by volcanism regions of the world. It consists of stair-like stepped flood basalt ( Trapp ) and now covers an area of more than 500,000 square kilometers. In the basalt of the Deccan Traps, the cave temples of Ellora and Ajanta were built, and a World Heritage Site by UNESCO.
Volcanic activity
The volume of basaltic lava flows preserved is about 500,000 km ³. Estimates of the original extent go out of more than 1.5 million square kilometers. The basalt layers can be up to 2,000 m thick today. Due to its expansion and its geologically relatively rapid formation of the Deccan Traps is an outstanding example of a large igneous province.
The volcanic activity of the Deccan Traps emerged, took place in front of about 66 million years ago. Together with the Trapp come in the Deccan before extensive Dyke Swarms. The Trapp consists almost exclusively of basaltic andesite and basalt tholeiitischem.
The duration of the formation of the Deccan Traps is controversial periods 500000-9000000 years are given. For the ejection of the basalts the passage of the Indian plate is to be responsible over a mantle plume. However, this theory is also controversial. As a cause of mantle plume comes into question, which feeds the Réunion hotspot in today's time.
The Deccan Traps as a reason for the extinction of the dinosaurs
Some scientists make associated with the deposition of the Deccan Traps climate change for the large extinction at the Cretaceous - Tertiary boundary in charge ( see for instance the Verne shot hypothesis), contrary to popular meteorite theory of dinosaur extinction. Additional support was this view by the discovery that the typical in the period in question at the Cretaceous - Tertiary boundary about 65 million years, deposition of iridium may arise not only in meteorite impacts, but also by volcanic activity. This theory remains controversial. It is suggested that the abrupt decrease of the fossil species can be explained by the increase in bad iridium concentration by continuous volcanic activity, but better by a single, short event such as a meteorite impact.