Linked from
The 4 pages that link to Upper mantle, each with the reason it gives.
LithosphereNarrower topic: The lithosphere includes only its mechanically strong uppermost part.
OphioliteNarrower topic: Ophiolites can include mantle rocks that once lay beneath oceanic crust.
Tectonic plateRelated: Its uppermost rigid portion travels as part of tectonic plates.
Oceanic core complexRelated: Mantle rocks may be exposed alongside lower crust in these domes.