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The
unique Armored Mud Balls
of the Connecticut Valley
By
Prof. Richard D. Little
Many
tons of monument-size rocks adorn the Greenfield Community College
Rock Park. Most notable of these samples are blocks with armored
mud balls, which were removed from the Old Red Bridges suspension
cable anchor foundation (now dismantled) on the Turners Falls side
of the Connecticut River at Unity Park. These examples are the best
preserved armored mud balls in the world and the only ones so far
discovered that were formed by streams. All of the other eight reported
armored mud ball sites around the world represent beach conditions.
The
men who removed these blocks from a former quarry in downtown Turners
Falls in 1877 must have noticed these strange, round features set
in the sandstone matrix, but they were first "officially"
discovered by the author in the early 1970s (see Little, 1982 in
geology article references). After further research, it was found
that these sedimentary features had never been noted by previous
geologists working in the valley, and also, that there are very
few other locations in the world where they have been discovered.
The
valley armored mud balls formed when large pieces of hard, dry mud
fell into a stream. As they tumbled in the current, they became
round as well as soft and sticky enough on the outside to have streambed
pebbles imbed into the soft exterior, forming the "armor".
To be preserved, the newly created armored mud balls must be buried
quickly in the stream's sandy gravel sediment. Otherwise, drying
will disintegrate the balls. So, in Mesozoic Turners Falls, the
conditions along the outer edge of an alluvial fan were just right
to form and preserve these unique balls. Armored mud balls have
recently (1997) been found in a new location, in the upper part
of the Sugarloaf formation in an East Deerfield quarry.
Other
places in the Connecticut Valley have sedimentary rocks with mud
chips, chunks, and balls, but no armored mud balls have ever been
discovered. But, keep your eyes open! There must be other armored
mud balls in other valley locations.
In
honor of their discoverer, some of the armored mud balls bear his
name. Armored mud balls less than 6 inches in diameter are known
as "Little" armored mud balls : ).
Contact
Information
Earth View LLC
Geology Education Products and Services
C/O Prof. Richard D. Little
6 Grand View Lane
Easthampton, MA 01027-1075
Phone / Fax (413) 527-8536
rdlittle2000@aol.com
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