Magnetite Ocean Floor

This distortion was recognized by icelandic mariners as early as the late 18th century.

Magnetite ocean floor.

As magma cools it locks in a recording of the earth s magnetic orientation or polarity at the time of fooling. More important because the presence of magnetite gives the basalt measurable magnetic properties these newly discovered magnetic variations provided another means to study the deep ocean floor the magnetite uralite and other minerals can be exposed by etching away the enclosing calcite with hydrochloric acid. These grains of magnetite can align themselves with orientation of the earth s magnetic field. This finding though unexpected was not entirely surprising because it was known that basalt the iron rich volcanic rock making up the ocean floor contains a strongly magnetic mineral magnetite and can locally distort compass readings.

Explains how magnetic polarity frozen into seafloor basalts reveals evidence for the creation of new seafloor at mid ocean ridges. Magnetic striping magnetic minerals are found in rocks. The reason tiny grains of magnetite found within the volcanic basalt that make up the ocean floor behave like little magnets. Magnetic stripes and isotopic clocks oceanographic exploration in the 1950s led to a much better understanding of the ocean floor.