RARE IMPACTITE Serpent Mound, OH, USA Slice Impact Melt Breccia, 152-gr (5.3-oz)

Description

There is, quite understandably, a growing interest in large meteorites and asteroids. That such large objects have struck Earth in the past, and will continue to in future, is something scientists have only fully begun to appreciate since about 1980. At present, there are over 170 recognized impact structures, and, every year, one or two new ones are being confirmed. Perhaps one hundred potential sites awaiting study. Confirmation of new impact craters takes a lot of time because there are probably more workers at the average McDonald's Restaurant than geologists who study impact craters!
The impact creates a crater far larger than the size of the impacting body.
Small craters resemble simple bowls; larger
ones may contain a central uplift or peak and multiple rings.
Local or area rock and soil are vaporized. Fallback material
may fall into or around the fresh crater, or be bourne many km (miles) away. Melted
fragments may be tossed at high
speed becoming aerodynamically-sculpted as impact melt glass bombs. Or
soil and sand may quickly cool into impact
melt glass. LONG after erosion has eraised signs of craters, such
impactites
may remain.
Offered here for your kind consideration is a very fine impactite, a 1.4-cm (~1/2-inch) thick slice of fascinating altered
rock from Serpent Mound, Ohio, USA. It is a colorful, complex slice of shattered and melted rock. This came from a
chunk which had obvious shatter cones.
I only recently cut this
unpolished slice of very hard impact breccia.
It weighs
152-grams (5 1/3-ounces) and is about 10.9 x 6.5-cm
(about
4.3 x 2.4-inches).
I will include the roughly 5.0-cm (2-inch) wide
descriptive label as shown printed on cardstock
that identifies the
specimen, the crater size and age. It also states this is
from the collection of Richard Dreiser
.
I photographed all but the last two images with the slice
wet with tap water
to accentuate the contrast and color. You can
achieve the enhanced color and contrast either by polishing it if you have the wherewithal, or, coating it with a thin layer of
clear polyurethane (sprayed or brushed on).
I would love to keep this specimen, however, after sixty years of collecting, I'm retired, and I must be getting rid of some of
my most cherished specimens. I can ship this via First Class Mail within the USA. I can also combine other winnings and ship
in the same carton to save you postage.
Wikipedia describes Serpent Mound crater as: ...
an eroded meteorite impact crater in Ohio that lies largely in Adams County
with the northern part mostly in Highland County except for a small northeast part in Pike County. It is classified as a complex
crater because it features a central uplift, a transition zone, and a ring graben (a ring-shaped trough in the outer part of the crater).
Although eroded, the original rim diameter has been estimated at 8-km (5.0-miles) and the age is estimated to be less than 320-million
years (Mississippian or younger). However, a 2010 paper suggested that the maximum rim diameter is 14-km (8.7-miles).The crater
is named after the Serpent Mound, an effigy mound, located on a plateau in Brush Creek Valley within
the crater. European-American
explorers had already noted the unusual terrain in the 19th century, and it is often speculated that the odd geological features inspired
Native Americans to construct the mound at that location. In 1980, the Serpent Mound Cryptoexplosive Structure was designated as
a National Natural Landmark by the National Park Service.
Here is a little more about impactites, written by me:
IMPACTITES may be mixtures of local shattered and melted local or area rock
and dust deposited many kilometers or miles away. These mixtures may harden into new rock types called impact breccia or fallback
breccia. Monomict breccia has only one variety of rock fragments while polymict breccia has two or more, sometimes with melted glass.
The pressure of impact from a comet or asteroid is far greater than the force of an earthquake, tsunami or super-volcano. It can
affect a number of local or area Earth rocks, sand and soil, sometimes profoundly so. Long after a meteorite impact crater has
disappeared from the landscape, buried or eroded away these, "impactites," may yet remain. The impact creates a crater far larger
than the size of the impacting body. Local and area rock and soil are vaporized. Small craters resemble simple bowls; larger ones
may contain a central uplift or peak and multiple rings. Melted fragments may be tossed at high speed becoming aerodynamically-
sculpted as impact melt glass bombs. Or the soil and sand may quickly cool into impact melt glass.