Magnetite
In the soil of many crop circles, large amounts of magnetite can be found, sometimes up to 800 times the normal quantity. This is caused by a strong magnetic field in the higher atmosphere (ionosphere) that attracts meteorite dust (magnetite) and sucks it down towards the Earth, where it hits the ground in a newly formed crop circle.
(For more information about this, see
In the case of Cherhill 1993, the magnetite concentration was so high, that it - still liquid due to the enormously high temperatures - dripped all over and around the plants and the soil (white chalk) before it coagulated. The amount of magnetite outside the formation was normal (max. 0,4 mg. magnetite per gram of soil).
In crop circles that appear during meteorite showers (like for instance the Perseïdes), the amount of magnetite can reach heights of 280 mg. per gram of soil!
