Define mantle plume and explain its role in plate tectonics. (Answer in 150 words)

A mantle plume is a long-lived column of anomalously hot, buoyant mantle material rising from deep within Earth, possibly near the core–mantle boundary, independent of ordinary plate-boundary convection.

Role in tectonics

• As hot material rises, decompression melting generates magma and hotspot volcanism away from plate boundaries.
• Surface expressions include shield volcanoes, volcanic island chains and large igneous provinces, as at Hawaii and the Deccan Traps.
• Plume heads can cause crustal uplift, doming, rifting and, in extreme cases, continental breakup.
• As a plate moves over a comparatively stationary plume, an age-progressive volcanic trail records plate direction and speed.

Scientific significance

Plumes transfer heat and matter from the deep mantle and help explain intraplate volcanism. Their exact depth, persistence and role in driving plate motion remain debated; evidence combines seismic imaging, geochemistry and geomorphology.

Keywords: UPSC GS1; inclusive development; constitutional values.

They are therefore important geological agents, though not a complete explanation of global plate tectonics.