The mantle
Magma is the semi-molten rock layer on which the crust floats.
35 - 60 Kms would be the uppermost mantle, which along with the crust forms the hard, brittle lithosphere. The Mantle is a semi-molten layer.
Continents and oceans are located on the Earth's outermost layer, known as the crust. Beneath the crust is the mantle, which consists of solid rock that can flow under high pressure. The molten rock, or magma, is found in the Earth's innermost layer, the outer core and the inner core.
The thin crust of the planet floats on the molten core.
The Mantle
Magma is fluid molten rock that exists under the Earth's crust.
The layer of the Earth which forms the tectonic plates is composed of the crust and uppermost mantle and is called the lithosphere.
magma
Magma
The layer that is thinnest under the oceans is the crust. While it is thinnest in those underwater regions, it is the thickest in the regions where mountains are.
The outer core is the only layer with molten in it.
The Earth's crust varies in thickness, averaging around 20-30 kilometers (12-18 miles) under continents and about 5-10 kilometers (3-6 miles) under oceans. However, there are regions where the crust can be much thicker or thinner due to geological activity.