No. The Earth's magnetic field consists of invisible lines of force, not rock. The mangetic fiild itself is driven by currents in the outer core, which is made of molten iron and nickel.
Mafic magma is generated at divergent boundaries because of decompression melting caused by the upwelling of hot mantle material due to the pulling apart of tectonic plates. As the plates move away from each other, the decrease in pressure enables the mantle material to melt and form mafic magma.
The mantle primarily contains mafic magma, which is rich in iron and magnesium. Felsic magma, which is rich in silica, is more commonly found in areas associated with continental crust or in volcanic arcs.
A mafic igneous rock formed deep within the Earth's crust is typically basalt. Basalt is fine-grained and rich in minerals like pyroxene, olivine, and plagioclase. It commonly forms from the solidification of magma that has originated from the mantle.
Mafic volcanic rocks reach the Earth's surface through volcanic eruptions. These rocks originate from the mantle and are rich in magnesium and iron. When magma containing mafic composition rises to the surface, it can erupt as lava and form volcanic landforms like shield volcanoes or basalt flows.
Xenoliths are often mafic minerals because they originate from the Earth's mantle, which is composed of mafic rocks such as basalt and gabbro. These minerals are more likely to survive the extreme conditions of volcanic eruptions, which is how xenoliths are transported to the Earth's surface. Additionally, mafic minerals have higher melting points compared to felsic minerals, making them more resistant to being melted and destroyed during volcanic processes.
The mantle is ultramafic.
Its made up of both. Oceanic crust is mostly mafic magma (basalt) and continental crust is mafic and felsic. The lithosphere also contains the upper portion of the upper mantle which is mostly mafic. The earths crust is 60% Si02 (silicates). Felsic rocks are much more silicate heavy than mafic. So one would assume that the crust is more felsic than mafic. That's just my conceptual thought process so don't take me on my word. Then again, the lithosphere also contains the upper mantle which is heavily mafic. So maybe the lithosphere in total is more mafic? Basically just typing thoughts down as they enter my brain. Answer I know for certain- Lithosphere is mafic and felsic.
Mafic magma is generated at divergent boundaries because of decompression melting caused by the upwelling of hot mantle material due to the pulling apart of tectonic plates. As the plates move away from each other, the decrease in pressure enables the mantle material to melt and form mafic magma.
Mafic and ultramafic minerals, high in magnesium and iron.
The mantle primarily contains mafic magma, which is rich in iron and magnesium. Felsic magma, which is rich in silica, is more commonly found in areas associated with continental crust or in volcanic arcs.
A mafic igneous rock formed deep within the Earth's crust is typically basalt. Basalt is fine-grained and rich in minerals like pyroxene, olivine, and plagioclase. It commonly forms from the solidification of magma that has originated from the mantle.
A Mafic Extrusive Igneous Rock.
Mafic volcanic rocks reach the Earth's surface through volcanic eruptions. These rocks originate from the mantle and are rich in magnesium and iron. When magma containing mafic composition rises to the surface, it can erupt as lava and form volcanic landforms like shield volcanoes or basalt flows.
Xenoliths are often mafic minerals because they originate from the Earth's mantle, which is composed of mafic rocks such as basalt and gabbro. These minerals are more likely to survive the extreme conditions of volcanic eruptions, which is how xenoliths are transported to the Earth's surface. Additionally, mafic minerals have higher melting points compared to felsic minerals, making them more resistant to being melted and destroyed during volcanic processes.
Melting points vary with pressure. In nearly all substances the melting point increases with increasing pressure. The peridotite in the mantle is extremely hot and under immense pressure. When it is decompressed some melting occurs. The composition is not uniform and some minerals have lower melting points than others. The mafic minerals will be able to melt while the ultramafic mineralls generally will not.
As the plates diverge, upper mantle rock rises and undergoes decompression melting along the rift. Because the upper mantle is comprised of mafic rock, the subsequent melt of this rock produces a mafic magma. Basalt and its coarse-grained intrusive twin, gabbro, are produced when this mafic magma solidifies.
The Earth's mantle mostly contains solid rock composed of silicate minerals rich in magnesium and iron. It is made up of ultramafic and mafic rocks such as peridotite and pyroxenite. The mantle is a key layer of the Earth's structure located between the crust and the core.