Question

IT IS INCORRECT TO SAY THAT THE CRUST IS BROKEN UP INTO TECTONIC PLATES. EXPLAIN WHY THIS IS FALSE

Answer 1

i dont know i didnt read it yet

Answer 2

That statement is false because tectonic plates are not just pieces of Earth’s crust — they are pieces of the lithosphere, which includes both the crust and the rigid uppermost part of the mantle. Key points:

- Definitions: the crust is the thin outermost compositional layer of Earth. The lithosphere is a mechanical/thermal layer made of crust plus the cold, rigid uppermost mantle. The asthenosphere beneath is weaker and flows, allowing the lithosphere to move.
- Tectonic plates = lithospheric plates. Plates behave as rigid blocks and consist of crust + lithospheric mantle, not crust alone.
- Thickness contrast: oceanic crust is only ~7 km thick, but oceanic lithosphere can be tens to ~100+ km thick. Continental crust may be 30–70 km thick while continental lithosphere commonly extends 100–250+ km. That shows most of a plate’s thickness is mantle, not crust.
- Physical reason: plate motion and interactions are governed by the mechanical properties and temperature structure of the lithosphere and asthenosphere, so the mantle portion matters critically.
- Observable consequences: subduction involves oceanic lithosphere (crust + mantle) sinking into the mantle; mid-ocean ridges build new oceanic lithosphere (not just crust). Continental collisions deform crust but the plate boundary is between lithospheres.
- Exceptions/complexities: crust can be internally deformed, broken into terranes, or occasionally decoupled from the lithospheric mantle (delamination), but that does not make plates equal to crust.

In short: tectonic plates are pieces of the lithosphere (crust plus uppermost mantle), so saying “the crust is broken up into plates” is misleading.