|Bedrock map of North America USGS|
This is a tale about how riches were overlooked in
Montana and Wyoming
by gold seekers in days of yore. In
these three states a whole diamond province has been overlooked in the
kimberlites by the hundreds that underlie these states. The diamonds can also be found in lamproites,
lamprophyres and other cryptovolcanic structures that are associated by the
Wyoming Craton underlying these three states.
Many of the larger targets lie right next to I-80 between Cheyenne
and Laramie that remain
unexplored. This area was originally
discovered by early gold miners who discovered it contained little or no gold
so they passed it on.
Subsequent discoveries indicate this may be one of the most unexplored diamond provinces in
North America where the
diamonds can be found in the carbonate rich sediments found in a Archean
gneiss. More then fifty depressions have
been discovered here suggesting cryptovolcanic activity that lie east of the
State Line diamond district. It is
thought these depressions could be kimberlites containing possibly large
amounts of diamonds.
Ongoing exploration suggests that the Wyoming Craton contains a world-class diamond province and like the diamond province near
also contains large deposits of
colored gemstones as rubies and sapphires.
This craton is found covering a large portion of Marathon,
The Wyoming Craton aside from covering several western states also includes exposures in
and Saskatchewan. Diamonds have
been discovered in both the kimberlites and lamprophyres in Montana,
Kansas and Nebraska
as well as Canada.
Another potential place where you can look is in any conglomerates that are derived from the lamprophyres and kimberlites of the Wyoming Craton. One of my prospecting buddies has found a diamond deposit like this near
Another Canadian prospecting buddy that lives in western Marathon,
has also found probable diamonds in his part of the province.
It isn’t just diamonds that can be found there; recently one of the world’s largest deposits of rare earth metals was found in Nebraska, When you start poking around in this ancient craton you never know what you’re likely to find.
The Wyoming Craton has the greatest southwestern outcrops of Archean rocks in
North America. Theoretically terranes like this have deep
roots in the lithosphere that according to Clifford’s rule this deep keel is
necessary for the formation of kimberlites with their association with
diamonds. Although this terrane wasn’t
deformed during the
Ancestral Rockies Orogeny it was pervasively deformed during the Laramide Orogeny and one theory has it that its deep keel was removed partially or wholly allowing it to be deformed during the Cretaceous or later.