Deccan Traps in the context of "Mantle plume"

The Deccan Plateau (/ˈdɛkən/ DEK-ən ) is a geographic formation that extends over an area of 422,000 km (163,000 sq mi) on the southern part of the Indian peninsula. It stretches from the Satpura and Vindhya Ranges in the north to the northern fringes of Tamil Nadu in the south. It is bound by the mountain ranges of the Western Ghats and the Eastern Ghats on the sides, which separate the region from the Western and Eastern Coastal Plains respectively. It covers most of the Indian States of Maharashtra, Karnataka, Telangana and Andhra Pradesh excluding the coastal regions, and minor portions of Tamil Nadu and Kerala.

The plateau is marked by rocky terrain with an average elevation of about 600 m (2,000 ft). It is subdivided into Maharashtra Plateau, Karnataka Plateau, and Rayalaseema and Telangana Plateau. The Deccan Traps in the northwest were formed by multiple layers of igneous rock deposited by basaltic lava flows following a massive volcanic eruption occurred at the end of the Cretaceous period (66 mya). The underlying bed consists of granite and sedimentary rocks formed during the Precambrian era and the formation of Gondwana.

The Paleocene (IPA: /ˈpæli.əsiːn, -i.oʊ-, ˈpeɪli-/ PAL-ee-ə-seen, -⁠ee-oh-, PAY-lee-), or Palaeocene, is a geological epoch that lasted from about 66 to 56 Ma (million years ago). It is the first epoch of the Paleogene Period in the modern Cenozoic Era. The name comes from Ancient Greek παλαιός (palaiós), meaning "old", and καινός (kainós), meaning "new", translating to "the old part of the Eocene".

The epoch is bracketed by two major events in Earth's history. The K–Pg extinction event, brought on by an asteroid impact (Chicxulub impact) and possibly volcanism (Deccan Traps), marked the beginning of the Paleocene and killed off 75% of species, most famously the non-avian dinosaurs. The end of the epoch was marked by the Paleocene–Eocene Thermal Maximum (PETM), which was a major climatic event wherein about 2,500–4,500 gigatons of carbon were released into the atmosphere and ocean systems, causing a spike in global temperatures and ocean acidification.

A flood basalt (or plateau basalt) is the result of a giant volcanic eruption or series of eruptions that covers large stretches of land or the ocean floor with basalt lava. Many flood basalts have been attributed to the onset of a hotspot reaching the surface of the Earth via a mantle plume. Flood basalt provinces such as the Deccan Traps of India are often called traps, after the Swedish word trappa (meaning "staircase"), due to the characteristic stairstep geomorphology of many associated landscapes.

Michael R. Rampino and Richard Stothers (1988) cited eleven distinct flood basalt episodes occurring in the past 250 million years, creating large igneous provinces, lava plateaus, and mountain ranges. However, more have been recognized such as the large Ontong Java Plateau, and the Chilcotin Group, though the latter may be linked to the Columbia River Basalt Group.

Insular India was an isolated landmass which became the Indian subcontinent. Across the latter stages of the Cretaceous and most of the Paleocene, following the breakup of Gondwana, the Indian subcontinent remained an isolated landmass as the Indian Plate drifted across the Tethys Ocean, forming the Indian Ocean. The process of India's separation from Madagascar first began 88 million years ago, but complete isolation only occurred towards the end of the Maastrichtian, a process that has been suggested to be the creation of the Deccan Traps. Soon after, the land mass moved northward rather quickly, until contact with Asia was established 55 million years ago. Even then, both landmasses did not become fully united until around 35 million years ago, and periods of isolation occurred as recently as 24 million years ago.

Thus, for a period of 53 million years India retained a degree of isolation, 11 of which it was a complete island continent. This allowed its local biota to follow the typical patterns seen in islands and diversify in unique ways, much as in modern Madagascar, its sister landmass. Faunal interchanges with other landmasses, like Africa and Europe (then an archipelago of islands across the Tethys) occurred during this period, and a considerable Asian influence can already be seen long before contact was made. This rendered India rather peculiar as not just an isolated continent but also a "stepping stone" in the dispersal of many animal and plant clades across Africa, Europe, Madagascar, Asia and possibly even Oceania. Still, several "archaic" clades managed to survive. The vast majority of India's terrestrial vertebrate life was wiped out in the Cretaceous-Paleogene extinction event; only 3 extant tetrapod lineages can trace their ancestry to Cretaceous India. Most of India's few other surviving Gondwanan lineages were outcompeted during the Paleogene by newly-arriving lineages. However, plants and invertebrate fauna were less affected.

Trap rock, also known as either trapp or trap, is any dark-colored, fine-grained, non-granitic intrusive or extrusive igneous rock. Types of trap rock include basalt, peridotite, diabase, and gabbro. Trap is also used to refer to flood (plateau) basalts, such as the Deccan Traps and Siberian Traps. The erosion of trap rock created by the stacking of successive lava flows often creates a distinct stairstep landscape from which the term trap was derived from the Swedish word trappa, which means "stairs".

The slow cooling of magma either as a sill or as a thick lava flow sometimes creates systematic vertical fractures within the resulting layer of trap rock. These fractures often form rock columns that are typically hexagonal but could be four- to eight-sided.

India is a union of twenty-eight states and eight union territories. As of 2011, with an estimated population of 1.210 billion, India occupies 2.4 percent of the world's land surface area but is home to 17.5 percent of the world's population. The Indo-Gangetic plains are among the most densely populated areas of the world. The eastern and western coastal regions of Deccan Traps are also densely populated regions of India. The Thar Desert in western Rajasthan is one of the most densely populated deserts in the world. The northern and north-eastern states along the Himalayas contain cold arid deserts with fertile valleys. These states have less population density due to indomitable physical barriers.