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How do records of magnetic reversals show that plates move apart?
As the molten material rises and cools, some magnetic minerals line up with the Earth's magnetic field. When the material hardens, the minerals are permanently fixed like tiny compass needles pointing north and south. Whenever the magnetic field reverses, the cooling minerals record the change.
What is fossil magnetism?
In hot Iron bearing rocks or magmas the iron minerals they contain align themselves parallel to the Earth's magnetic field. When they cool below about 500 degrees Celsius the the iron minerals 'freeze' in this magnetic orientation and are no longer able to adapt to any changes in the Earth's field (which occasionally reverses polarity and wanders). This frozen magnetic alignment is a fossil of the ancient magnetic field and can be 'read' to find out what the Earth's magnetic field has been doing in the past.
Minerals in igneous rocks can show the direction of earths?
The Earth magnetic field changes approximately every 200,000 thousand years.
Is magnetic minerals occur naturally?
Yes
What causes the magnetic quality of feldspar?
Feldspar itself is not magnetic. Tiny inclusions of magnetic minerals produce the observed effects.
Magnetic minerals prove Earth has had?
A liquid iron core that spins creating a magnetic field
What is sea floor spreading and what evidence do we have to prove it is happening?
Magnetic minerals on the ocean floor.
How will magnetic minerals align in a rock if earth has no magnetic field?
Assuming there is no Earth magnetic field, and no other significant magnetic fields, they will not allign in any preferred direction.
What happens to minerals in rocks that cool in the presence of the Earth's magnetic field?
If the rock contains magnetic minerals such as Heamatite then these minerals will orientate their own magnetic field lines to match those of the earth. As such we see bars of rock as we move away from a mid-ocean ridge with different magnetic orientations to match the switching magnetic poles of the earth.
The alignment of iron minerals in rocks when they are formed reflects the fact that Earth's has reversed itself several times in the past?
magnetic field.
What properties of iron bearing minerals on the seafloor support the theory of seafloor spreading?
iron bearing minerals can record Earth's magnetic field direction. when Earth's magnetic field reverses, newly formed iron bearing minerals will record the magnetic reversal. magnetic reversals show new rock being formed at mid-ocean ridges. This helped explain how the crust could move
How do records of magnetic reversals show that plates move apart?
As the molten material rises and cools, some magnetic minerals line up with the Earth's magnetic field. When the material hardens, the minerals are permanently fixed like tiny compass needles pointing north and south. Whenever the magnetic field reverses, the cooling minerals record the change.
What minerals have magnetic properties?
The following minerals have magnetic properties: Magnetite and hematite are ferromagnets. Ferrites and garnets are ferrimagnetic. Quartz, calcite, and mica are all magnetic. Although they have a small magnetic attraction, these minerals do not remain magnetic.
What is fossil magnetism?
In hot Iron bearing rocks or magmas the iron minerals they contain align themselves parallel to the Earth's magnetic field. When they cool below about 500 degrees Celsius the the iron minerals 'freeze' in this magnetic orientation and are no longer able to adapt to any changes in the Earth's field (which occasionally reverses polarity and wanders). This frozen magnetic alignment is a fossil of the ancient magnetic field and can be 'read' to find out what the Earth's magnetic field has been doing in the past.
How does solidified magma come to be magnetic?
As magma solidifies to form rock, iron-rich minerals in the magma align with Earth's magnetic field in the same way that a compass needle does. When the rock hardens, the magnetic orientation of the minerals becomes permanent. This residual magnetism of rock is called paleomagnetism.
How solidified magma comes to be magnetic?
As magma solidifies to form rock, iron-rich minerals in the magma align with Earth's magnetic field in the same way that a compass needle does. When the rock hardens, the magnetic orientation of the minerals becomes permanent. This residual magnetism of rock is called paleomagnetism.
How does the Earth's magnetic field result from the convection currents?
Moving electric conductors generate magnetic fields. The molten portions of the Earth's core are conductive and there are so many free elctrons in the lava that electric currents are induced generating magnetic fields as the hotter iron and nickel rich liquefied minerals flow away from the center of the core to be replaced by cooler minerals.
