Basalts contain magnetic minerals which get aligned in the direction of the magnetic field when the rock solidifies.
The rocks on the ocean floor are magnetic.
Magnetic striping magnetic minerals are found in rocks.
Magnetic direction of rock changes as earth s magnetic poles drift.
Eruptions of molten material magnetic stripes in the rock of the ocean floor and the ages of the rocks themselves.
This evidence led scientists to look again at wegener s hypothesis of continental drift.
Identify the factors that cause magnetic stripes to form along the ocean floor.
Several types of evidence supported hess s theory of sea floor spreading.
These two things were the magnetic striping on the ocean floor and the age of seafloor rocks.
The oceanic crust displays a pattern of magnetic lines parallel to the ocean ridges frozen in the basalt.
The fraction of a rocks overall magnetization that is a viscous remanent magnetization is dependent on the magnetic mineralogy.
These stripes of normal and reverse magnetic fields with different sizes can be matched with the geomagnetic reversals records obtained from continental rocks already dated.
Evidence from molten material.
Evidence for sea floor spreading.
Among the new findings was the discovery of zebra stripe like magnetic patterns for the rocks of the ocean floor.
As rocks crystallize from lava at the ridges they literally record the magnetic field of the earth at the time of their creation.
These patterns were unlike any seen for continental rocks.
The ocean floor is mainly made up of basalt which is formed as a result of underwater volcanic activity.
Plates move as new rock forms which causes magnetic direction to skew away.
Magnetic stripes and isotopic clocks oceanographic exploration in the 1950s led to a much better understanding of the ocean floor.
A symmetrical pattern of positive and negative magnetic lines emanates from the mid ocean ridge.
This is how scientists get the age of the seafloor.
Plate tectonics and reversals of the earth s magnetic field are responsible for the magnetic stripes found on the ocean floor.
The magnetism of mid ocean ridges helped scientists first identify the process of seafloor spreading in the early 20th century.
Paleomagnetic procedure collecting samples on land.
Magma acquires the magnetic direction present on earth when it hardens into rock 3.
New rock is formed by magma at the mid ocean ridges and the ocean floor spreads out from this point.
Select the two correct answers.
The oldest rocks on the ocean floor are 200 mya very young when compared with the oldest continental rocks which date from 3 8 billion years ago.
When magma flows out of a mid ocean ridge small magnetic minerals in the magma align themselves to point in the direction of the earth s current magnetic north.
