I am not sure if this is a man made cut of the limestone or if
this is caused by natural erosion. If it is manmade, it must of
been done many years ago.
Regardless it is still a good example of Burlington limestone found
in the region.
The Burlington Formation is a marine limestone, found in rock
layers laid down during the Mississippian Period (325-360 million
years ago). The Mississippian Period was relatively short-lasting
only 35 million years-and its fossil record is almost entirely
marine. This is due to the flooding of North America called the
Kaskaskia transgression, which began during the Devonian Period
(380-450 million years ago). This was interrupted at the end of the
Devonian Period by partial regression, but deposition continued
uninterrupted into the Mississippian Period. The Kaskaskia Sea
reached its greatest extent about the middle of the Mississippian
Period, and late Mississippian sedimentary rocks of the basins mark
its recession. This recession also marks the boundary between the
Mississippian and Pennsylvanian Periods in the North America.
The Mississippi Valley was covered by this clear, shallow, warm
inland sea that advanced from the south. During this period,
limestone was deposited to a total thickness of more than 2,000
feet in some areas. These limestone deposits occur almost
continuously from Iowa to Alabama. The high bluff along the
Mississippi River north of St. Louis are typical of this
deposit.
Present in nearly all major Mississippian outcrop regions in
Missouri, the Burlington Limestone is widespread throughout the
mid-continent region. It is known from Iowa to northwestern
Arkansas and from western Illinois to western Kansas. It is present
throughout Missouri, except in the Ozark uplift, where it has been
removed by erosion. Differentiation of the Burlington with the
overlaying, lithologically similar Keokuk Limestone is often
difficult or impossible, so the sequence of Osagean limestones is
sometimes identified as "Burlington-Keokuk Limestone"
As observed in most exposures, the Burlington Limestone is
unusually course-grained, crystalline, crinoidal limestone. Its
texture is sufficiently distinctive and persistent to permit
recognition of the formation commonly on this basis alone. The
Burlington Limestone is made of almost entirely on the remains of
various fossils, by far the most important of which are crinoids.
Some portions of the Burlington, however, are not so evidently
crinoidal, as for example, the so-called "white ledge" quarried in
the northeastern part of Missouri. Parts of the Burlington
formation also consist of thin, uneven cherty beds and cherty
nodules.
To get credit for this EC, post a photo of you with the limestone
in the back ground just like the the posted picture of me at the
spot and answer the following questions.
1. What are the natural colors in the limstone on the left section
of exposed limestone?
2. What is the elevation at the posted coordinates?
3. What is located directly above the limestone cut.
Logs with no photo of the actual cacher logging the find or failure
to answer questions or negative comments will result in a log
deletion without notice. Exceptions will be considered if you
contact me first (I realize sometimes we forget our cameras or the
batteries die).
I have used sources available to me by using google search to get
information for this earth cache. I am by no means a geologist. I
use books, internet, and asking questions about geology just like
99.9 percent of the geocachers who create these great Earth Caches.
I enjoy Earth Caches and want people to get out and see what I see
everytime I go and explore this great place we live in.