Question QUESTION: Where I live there are large amounts of metallic black dust (a bit smaller than the size of salt) that a magnet can easily pick up. They are all over the forest floor and lake shores. The size is uniform with very little variance. What is it and how did it get there?
I need some more info to be able to understand the situation. (1) Is there any iron-steel factory in and around your area or lake-forest area? (2) How strongly does the magnet attracts the metallic black dust, say from a distance of few centimetres or the magnet has to touch the dust? (3) What type of soil is around the area you live or lake-forest area? (4) Are there any black hard rocks in vicinity which could be magnetite bearing from which the black dust is coming by wind (as you say its fine grained, the fine magnetite dust can move in series of jump if the weathered /soil is dry or you live in an area which in by and large close to desert).
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QUESTION: There are no factories any where around here and no large black rocks. The black powder is much finer than salt, it is not attracted to metal but is very attracted to magnets. It does not rust. Holding a magnet about 1/2 inch picks up all the dust. I live in Maryland U.S.A. and most of the nearby rocks are quartz, sandstone, mica.The particles tend to move to the surface of the dirt especially if mixed with water.
Answer Its intriguing!
PL. show a small sample of magnetic dust to a local geologist, may be you can contact some prof. of Geology Department of a college/univ. If you have a USGS office close by you can also contact them and pl. post your findings.
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