Cobblestone streets in Detroit

[beachboy]

"Archaeologists tell us the roughly 5000 open pit mines running for a hundred miles on the north shore of Upper Michigan [actually, Superior] were worked from aproximately 3000 - 1200 BC to extract anywhere from 100 - 500 thousand pounds [[or some texts say tons) of essentially pure copper.

Fact: Copper was mined since antiquity by native people in the Western Lake Superior area. Large deposits of elemental copper [[versus sulfide or oxide ores) are a feature of the pre-Cambrian volcanic geology of the Keeweenaw Peninsula - an arm of the UP that juts northeastward into L. Superior.

A good source for reading about the history of copper mining in the UP is the book "Red Metal", by Harry Benedict [[a now-deceased professor at MTU):

http://www.amazon.com/gp/offer-listi...&condition=all

When I worked in the A.E. Seaman Mineral Museum as a student at Michigan Tech [[many years ago) we were cataloging some mineral samples from an old cabinet. In this piece of 19th Cent. furniture was a wooden cigar box with copper spear points that dated from 3,000 BCE. These were made by Native Americans on Isle Royale [[where they were found in the 19th Cent.)

Such artifacts can still be viewed in the Midwestern US. For example, here is a pic of some spear points like the ones we found:



and you can read more about it at:

http://www.uwlax.edu/mvac/preeuropea...erculture.html

My apologies for digressing from the street-paver thread,
so here a few comments about that...

1 - From http://en.wikipedia.org/wiki/Cobblestone

"Cobblestones are stones that were frequently used in the
pavement of early streets. "Cobblestone" is derived from the very old English word "cob", which had a wide range of meanings, one of which was "rounded lump" with overtones of large size. "Cobble", which appeared in the 15th century, simply added the diminutive suffix "le" to "cob", and meant a small stone rounded by the flow of water; essentially, a large pebble. It was these smooth "cobbles", gathered from stream beds, that paved the first "cobblestone" streets.

"Cobblestones were largely replaced by quarried granite setts in the nineteenth century. Cobblestone is often wrongly used to describe such treatment. Setts were relatively even and roughly rectangular stones that were laid in regular patterns. They gave a smoother ride for carts than cobbles, although in heavily used sections, such as in yards and the like, the usual practice was to replace the setts by parallel granite slabs set apart by the standard axle length of the time.

"Cobblestoned and setted streets gradually gave way to macadam roads, and later to tarmac, and finally to asphalt at the beginning of the 20th century. However, cobble­stones are often retained in historic areas, even for streets with modern vehicular traffic. Many older villages and cities in Europe are still paved with cobblestones. In recent decades, cobblestones have become a popular material for paving newly pedestrianised streets in Europe. In this case, the noisy nature of the surface is an advantage as pedestrians can hear approaching vehicles."

2 - Lower Michigan, being of glacial geology, is richly supplied with cobbles - stream beds being good sources. Cobbles can be found throughout the USA - here is a pic of a dry stream bed rich with cobblestones "out West":



3 - Cobblestone streets abound in the USA, for example, in Boston - and Van Buren street hill & bridge [[across the Brandywine River) in Wilmington DE to provide a bit of traction on wintry days: