The Full Wiki

Rock flour: Map


Wikipedia article:

Map showing all locations mentioned on Wikipedia article:

Rock flour, or glacial flour, consists of clay-sized particles of rock, generated by glacial erosion or by artificial grinding to a similar size. Because the material is very small, it becomes suspended in river water making the water appear cloudy, which is sometimes known as glacial milk.

If the river flows into a glacial lake, the lake may appear turquoise in color as a result. When flows of the flour are extensive, a distinct layer of a different color flows into the lake and begins to dissipate and settle as the flow extends from the increase in water flow from the glacier during snow melts and heavy rain periods. Examples of this phenomenon may be seen at Lake Louisemarker and Peyto Lakemarker in Canadamarker and Gjendemarker lake in Norwaymarker.


Typically, natural rock flour is formed during glacial migration, where the glacier grinds against the rock beneath it, but also is produced by freeze-and-thaw action, where the act of water freezing and expanding in cracks helps break up rock formations. Multiple cycles create a greater amount.

Although clay-sized, the flour particles are not clay minerals, but typically, ground up quartz and feldspar. Rock flour is carried out from the system via meltwater streams, where the particles travel in suspension. Rock flour particles may travel great distances either suspended in water or carried by the wind, in the latter case, forming deposits called loess.

Agricultural use

Some agronomists believe that rock flour has a powerful effect in restoring trace minerals to soil. An early experimenter was the Germanmarker miller, Julius Hensel, author of Bread from Stones, who reported successful results with steinmehl (stonemeal) in the 1890s. His ideas were not taken up due to technical limitations and, according to proponents of his method, because of opposition from the champions of conventional fertilisers.

John D. Hamaker argues that widespread remineralization of soils with rock dust will be necessary to reverse soil depletion by current agriculture and forestry practice.

While this originally was an alternative concept, increasing mainstream research has been devoted to soil amendment and other benefits of rock flour application: for instance, a pilot project on the use of glacial rock, granite and basaltic fines by the U.S.marker Department of Agriculturemarker exists at the Henry A.marker Wallace Beltsville Agricultural Research Centermarker. The SEER Centre in Scotland is a leading source of information on the use of rock dusts and mineral fines. The Soil Remineralization Forum was established with sponsorship from the Scottish Environment Protection Agency and has commissioned a portfolio of research into the benefits of using mineral fines. The Forum provides an interface among research, environmentalists, and industry.


Internal links

External links

Embed code:

Got something to say? Make a comment.
Your name
Your email address