|The rocks as Rock City are huge sandstone concretions.
In an area about the size of two football fields, 200 rocks--some as large as houses--dot the landscape. There is no other place in the world where there are so many concretions of such giant size.
Owned by a local non-profit corporation, the site is operated as a public park. Open 9AM to 5 PM daily, May 1 to September 1. Admission is $3. /adult and $. 50/child.
Geologists are in general agreement these concretions were formed millions of years ago of Dakota Sandstone, which was deposited when an Inland Sea covered areas of Kansas.
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|At one time, the surface of
the land was higher than it is now, and the rock occupying this space was
a sandstone, where individual grains of sand were poorly cemented together.
Underground waters containing dissolved calcium carbonate circulated through
the porous rock with ease and in doing so deposited calcium carbonate in
the open spaces between the sand grains, thereby cementing them together.
Instead of proceeding evenly, the precipitation of this natural cement began
at a number of scattered points where, perhaps, a fossil or an
extra large grain of sand served as a nucleus. It continued outward in all directions from these centers. The result was the formation of a number of spherical bodies of tightly cemented sand grains scattered from the sandstone mass.
Had the cementation continued long enough, the spheres would have grown together and the huge rock would have become a homogenous mass. But before this could take place, erosion by wind, rain, wash and running water began to lower the surface. Of course, the loosely cemented sand was the easiest to carry away, so it went first. The concretions resisted the erosive activity, so were uncovered and left lying on top of the present surface.
There are other examples of these phenomena throughout the world, but none are as unique or large as here.
Rock City is owned and operated as a park by Rock City, Inc., a local non-profit corporation. It is open 9 a.m. to 5 p.m. daily, May 1 to September 1. A small admission fee is charged and used to maintain the park and offset its operating costs. Further information about Rock City can be obtained from Rock City, Inc., 1051 Ivy Road, Minneapolis, Kansas 67467 (785.392.2577).