At 11:46 PM -0500 11/11/97, ivanwill at ix.netcom.com wrote:
> I spent last summer on a tributary of the Rio Negro in Brazil. The
>acids that
>produced the "leaf stains on concrete" mentioned by David Starrett are
>responsible for
>the "black water" rivers of tropical rain forests. Tropical black water
>rivers and streams
>occur in areas of sandy soils--the sand serving as a tea strainer,
>holding the leaf litter
>back while allowing the leachant to filter into the streams. Some of the
>black water
>streams look very black, like strong tea, while others are more of an
>amber color. The pH
>of the streams that I=3D92ve tested were around 4.2-5.4. Quite acid,
>considering the amount of
>rainfall in these rain forests. The leaves and seed pods--especially
>some of the
>Lecithedacea seed pods--when placed in a cup of water quickly produced a
>dark colored
>tea.
Another interesting place to see amber rivers includes
Taquamenon Falls in Michigan, USA. Here the waters are
also tea-colored, and the falls, being of different water
"thickness" are beautifully stained colors ranging from
white (real thin sprays) to deep brown (heavy flows) and
just about every shade of yellow-amber-brown in between.
Niagara is impressive, but not very colorful by comparison.
ross
_______________________________________________________________
Ross Koning | koning at ecsu.ctstateu.edu
Biology Department | http://koning.ecsu.ctstateu.edu/
Eastern CT State University | phone: 860-465-5327
Willimantic, CT 06226 USA | fax: 860-465-4479
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