FOSSILS tell us stories. Fossils tell us of many types of life forms of long ago. Fossils help interpret past conditions of life on the land or life under water in once vast shallow oceans. Marshall County's contribution to fossil discoveries is a chapter of our local history that needs to be acknowledged. A huge thank you is still appropriate today to B.H. Beane for his intense interest in local geology.
Burnice Beane was the son of a Quaker minister and farmer. He grew up living next to a limestone quarry. Limestone strata were relatively close to the shallow overburden of soil layers. Since local construction needs could be met by removing the soils, blasting the rock and then crushing the stone for all kinds of building needs, a rock quarry was an essential part of early economic businesses.
Beane took great interest in the workers' tasks, and he also took great interest in sporadic findings of rock layers that had exposed parts of fossils. Fossil stone flowers (crinoids), also called sea lilies, started to appear fairly often as early as 1874. Other geologists already knew that creatures of many species lived on sunlight shallow ocean muddy-like surfaces. We know now that these sea lilies were animals, not plants.
Quarry operations in old times was a labor intensive job, much of it hand work. Workers would occasionally find just the right slab of limestone that had broken open along a bedding plane to expose unusual bouquets of "stone flowers."
Workers could see that these finds were concentrated in "oval nests" of 10 to 15 feet in diameter. Even these workers would collect a few samples to take home. Lots of crinoid rock slabs were found from 1874-1890.
Burnice Beane as a 10-year-old boy was one of the collectors. He was so fascinated by the rocks and their revelations that he pestered quarry workers to set aside any chunks of stone that held indications on their edges of fossil remnants.
Beane also took great advantage of professional geologists that visited the quarry to ask unlimited questions. To their credit, those geologists, an idol to Burnice, obliged with straight forward and truthful answers to help educate this young lad. From that start of basic curiosity, Burnice Beane made a lifelong hobby turn into his mission in life. He collected a lot of fossils.
In an article written by Richard Boyt in 1962, Beane said "I pestered them with endless questions, and they answered me with in-exhaustible patience. I soon became a fossil collector and spent my spare time at the quarry."
By 1890, a first good nest of fossil crinoids had been removed. Then everything was apparently over until 1931 when a new blasting operation uncovered a new nest.
This second nest was located about 100 feet from the earlier discovery. It was a lens-shaped accumulation of crinoids. So began a race to hold back and preserve as much of this bed before crushing operations obliterated the rock slabs.
It was in this second nest that Beane was amazed by a new critter, starfish, in addition to crinoids and other animal shell molds. Starfish fossils are very rare and these were well preserved.
One of today's images shows a close up of starfish that Beane was able to carefully expose at his workbench using toothbrushes and dental picks. This slab also had well preserved sea urchins (12 of them) and two trilobites in addition to 183 starfish! What a great find.
A few years later, in 1933, another fossil nest was discovered. It had a diameter of about 18 feet. Between 1933 and 1937, more finds were made and these, in total, contained several thousand crinoids.
A big thank you is also in order to many unknown and unnamed quarry workers that spotted likely limestone slabs with fossils to set these rock slabs aside so they would not be destroyed. This portion of the Le Grand quarry where these fossil rich rocks came from closed in 1958.
Burnice and his son Lewis prepared many slabs for revelation of their internal secrets. A large slab would give hints of the bedding plane to focus on.
So with needles and small nails carefully placed around a slab edge, it was possible to carefully spit the rock along that bedding plane. Then by lifting the top half off the bottom half, those fantastic fossils would see the light of day again after a mere 359-323 million years, the time of shallow ocean depositions when these animals were alive. Careful scraping and dislodging of limestone matrix away from stem edges or starfish arms would reveal an improved replication of the mineralized shape of the animals.
Beane eventually though reluctantly sold much of his collection to Universities and Colleges in the states. He also sold specimens to museums in London, Paris, Holland, Capetown and Tokyo.
It takes special long-term environmental conditions for animal or some plant life forms to fall into a muddy basin, get covered gently with new sediments, and then more and more sediments until the weight of all that overburden compresses the forms into a mold-like setting. It is best
if low oxygen surrounds the dead animal.
The tissues of the animals were gradually replaced by minerals. To have a rare and great set of circumstances take place that allows scientists in modern times to discover these artifacts is remote, but when it happens, it is a good thing.
Le Grand area fossils lived during what geologists call Mississippian time when large but shallow salt water oceans covered Iowa and much of North America. It is known from rock records that at least ten cycles of sea advances and retreats off the land took place between 359 and 323 million years ago.
Deposits of material and also natural erosion of the same took place in an environment similar to what is found today in the Bahama Banks. After the withdrawal of the last seas, the land surface was subject to erosion and prolonged weathering. Over vast amounts of time, the land and its bedrock surfaces accumulated all kinds of debris and glacially deposited parent materials.
If we fast forward to modern geologic times, the Mississippian limestone layers, now hundreds of feet deep, can be drilled into for wells to supply fresh drinking water. Pore spaces between mineral grains in these supposedly solid rocks are filled with water. Wells can tap that source of water.
Quarry operations continue all over the Americas. The soil layers are removed to expose the bed rock top surface. That rock is mined for construction needs.
As the quarry digs deeper and deeper, supplies of quality rock are run through crushers to make different sizes for different purposes. The hole in the ground gets deeper and deeper as new layers of limestone or dolomite are removed. Ground water wants to seep into the quarry pit unless that water is continually pumped out.
Fossils have been found in many places throughout Iowa and other North American quarry sites. Enough fossils have been studied to learn more about geologic time, and how life in those long ago places was setting the stages for us humans to get curious, to want to learn more about ancient life forms, and to find answers to Earth's long natural history.
It is amazing what rock records can teach us. The nice thing about geologic rock records is that they do not lie to us, they tell the true stories of life long ago.
A place in Iowa where you can go to collect fossils is located 1.5 miles southwest of the city of Rockford. It is the site of the former Rockford Brick and Tile Company. The overburden soils were removed and left behind are those extremely rich deposits of Devonian age fossils.
The name of the park is Fossil and Prairie Park Preserve. If you go there, take a bucket and collect brachiopods shell casts to your hearts content. Corals are also available.
The Devoinian geologic time frame ended about 375 million years ago, so it is much older than the Mississippian limestone at Le Grand. This educational center is open seasonally for fossil enthusiasts.
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I will leave you with this quote from geologist Samuel Calvin, made in 1906, in his "Report on Geology of Iowa Counties." He said these words.
"The rocks in question, therefore, so far as relates to Iowa, are nothing more than the consolidated sands and muds of old sea bottoms preserving for our inspection samples of life that occupied the seas at the time each successive bed was in process of accumulation. Iowa has passed more time under the ocean than as dry land."
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Garry Brandenburg is the retired director of the Marshall County Conservation Board. He is a graduate of Iowa State University with a BS degree in Fish & Wildlife Biology.