Editing Deccan Traps (section)

==Theories of formation==
It is postulated<!-- {{by whom|date=November 2022}} see ref 'Basu,Renne,DasGupta' end of next sentence--> that the Deccan Traps eruption was associated with a deep [[mantle plume]].  High [[Helium-3|<sup>3</sup>He]]/[[Helium-4|<sup>4</sup>He]] ratios of the main pulse of the eruption are often seen in magmas with [[mantle plume]] origin.<ref>{{Cite journal|last1=Basu|first1=Asish R.|last2=Renne|first2=Paul R.|last3=DasGupta|first3=Deb K.|last4=Teichmann|first4=Friedrich|last5=Poreda|first5=Robert J.|date=1993-08-13|title=Early and Late Alkali Igneous Pulses and a High-3He Plume Origin for the Deccan Flood Basalts|url=https://www.science.org/doi/10.1126/science.261.5123.902|journal=Science|volume=261|issue=5123|pages=902–906|doi=10.1126/science.261.5123.902|pmid=17783739|bibcode=1993Sci...261..902B|s2cid=23709446}}</ref> The area of long-term eruption (the [[hotspot (geology)|hotspot]]), known as the [[Réunion hotspot]], is suspected of both causing the Deccan Traps eruption and opening the [[rift]] that separated the [[Mascarene Plateau]] from India. Regional [[crustal thinning]] supports the theory of this rifting event and likely encouraged the rise of the plume in this area.<ref name=":1" /> [[Seafloor spreading]] at the boundary between the Indian and [[African Plate]]s subsequently pushed India north over the plume, which now lies under [[Réunion]] island in the [[Indian Ocean]], southwest of India. The mantle plume model has, however, been challenged.<ref name="mantleplumes">Sheth, Hetu C. "[http://www.mantleplumes.org/Deccan.html The Deccan Beyond the Plume Hypothesis]." ''MantlePlumes.org,'' 2006.</ref>

Data continues to emerge that supports the plume model. The motion of the Indian tectonic plate and the eruptive history of the Deccan traps show strong correlations. Based on data from marine magnetic profiles, a pulse of unusually rapid plate motion began at the same time as the first pulse of Deccan flood basalts, which is dated at 67&nbsp;million years ago. The spreading rate rapidly increased and reached a maximum at the same time as the peak basaltic eruptions. The spreading rate then dropped off, with the decrease occurring around 63&nbsp;million years ago, by which time the main phase of Deccan volcanism ended. This correlation is seen<!-- {{by whom|date=November 2022}} ...see ref name=Cande--> as driven by plume dynamics.<ref name=Cande>{{cite journal | last1 = Cande | first1 = S.C. | last2 = Stegman | first2 = D.R. | year = 2011| title = Indian and African plate motions driven by the push force of the Réunion plume head | journal = Nature | volume = 475 | issue = 7354| pages = 47–52 | doi = 10.1038/nature10174 | pmid = 21734702 | bibcode = 2011Natur.475...47C | s2cid = 205225348 }}</ref>

The motions of the Indian and [[African Plate|African plates]] have also been shown<!-- {{by whom|date=November 2022}} ibid Cande--> to be coupled, the common element being the position of these plates relative to the location of the Réunion plume head. The onset of accelerated motion of India coincides with a large slowing of the rate of counterclockwise rotation of Africa. The close correlations between the plate motions suggest that they were both driven by the force of the Réunion plume.<ref name="Cande" />

When comparing the Na<sub>8</sub>, Fe<sub>8</sub>, and Si<sub>8</sub> contents of the Deccan to other major igneous provinces, the Deccan appears to have undergone the greatest degree of melting suggesting a deep plume origin. [[Olivine]] appears to have fractionated at near-[[Mohorovičić discontinuity|Moho]] depths with additional fractionation of [[gabbro]] ~6&nbsp;km below the surface.<ref name=":0" /> Features such as widespread [[faulting]], frequent [[dike (geology)|diking]] events, high heat flux, and positive [[Gravity anomaly|gravity anomalies]] suggest that the extrusive phase of the Deccan Traps is associated with the existence of a triple junction which may have existed during the Late Cretaceous, having been caused by a deep mantle plume. Not all of these diking events are attributed to large-scale contributions to the overall flow volume. It can be difficult, however, to locate the largest dikes as they are often located towards the west coast and are therefore believed to currently reside under water.<ref name=":1" />