Question

what layers iof nearth plays a role in tectonic plates

Answer 1

Tectonic plates are parts of the outer shell of the Earth and involve several layers. Key ones are:

- Lithosphere — the rigid outer shell that makes up the tectonic plates. It includes:
- the crust (oceanic or continental)
- the uppermost, relatively rigid part of the mantle (the lithospheric mantle)
Typical thickness: tens to ~200+ km depending on location (thinner under mid‑ocean ridges, thicker under old continental interiors).

- Asthenosphere — the mechanically weak, ductile part of the upper mantle directly beneath the lithosphere. Because it can deform and flow over geological timescales, lithospheric plates effectively “float” and move on the asthenosphere. Its depth and thickness vary with location (the lithosphere–asthenosphere boundary is commonly on the order of tens to a few hundred km depth).

Other related layers/processes:
- Deeper mantle (upper and lower mantle) — convective flow in the mantle transmits heat and momentum and helps drive plate motions (through ridge push, slab pull, mantle drag).
- Core — not part of the plates, but it provides heat (along with radioactive decay) that helps sustain mantle convection.

In short: the lithosphere (crust + uppermost mantle) constitutes the plates, and the asthenosphere (upper mantle below the lithosphere) is the layer that allows those plates to move; deeper mantle convection and core heat are the driving engine.