Assertion: mantle | /r/HasAspect | three main layers
Facets:
value: on the basis of mineralogy
type: CAUSE
Source sentences:
text: On the basis of mineralogy, the mantle is divided into three main layers, the upper mantle, which extends from the base of the crust to about 410 km depth, the transition zone, which extends down to about 670 km, and the lower mantle, which extends down to the core-mantle boundary at about 2900 km depth.