Reunion hotspot
Topic: Continental Drift, Sea-floor Spreading and Plate Tectonics · NCERT: Beyond NCERT
Meaning
The Reunion hotspot is a mantle plume that now lies under Reunion Island in the western Indian Ocean. A mantle plume is a column of unusually hot rock that rises from deep inside the earth and melts near the surface. The plume stays almost fixed while plates move over it. When India passed over it, huge floods of lava poured out and formed the Deccan Traps. The main pulse was about 66 million years ago, and India was still close to the equator at that time. As India kept moving north, the hotspot left a trail of volcanic rock on the sea floor called the Chagos-Laccadive Ridge.
Example
The Deccan Traps of Maharashtra and nearby states are thick layers of hardened lava from this hotspot. The Lakshadweep islands, off the Kerala coast, sit on the Chagos-Laccadive Ridge, and so do the Maldives and the Chagos islands.
Don't confuse with
- Kerguelen hotspot: it made the Ninety East Ridge and probably the Rajmahal Traps in eastern India. The Reunion hotspot made the Deccan Traps and the Chagos-Laccadive Ridge.
- Mid-oceanic ridge volcanism: there, lava comes up where two plates pull apart. A hotspot erupts in the middle of a plate, from a deep plume.