In 1993, record flooding resulted in upto 5 feet of water flowing over the Lake Coralville dam spillway. After the flood waters receded, it was discovered that 15+ feet river bottom and limestone downstream of the dam spillway had been washed away revealing 375 million year old bedding planes with diverse and abundant fossils. An outdoor interpretive facility on the site was completed in 2001. Part of this facility is the placing of hexagonal (six-sided) bronze plaques, called discovery points, have been placed at various points of interest throughout the site. You will find a brochure showing the discovery point locations in the entry plaza. In order to log this cache you need to answer the following questions about the fossil site via an email to me (please do not post your answers in your log):
1. Study the various intrepetive markers at the site and complete this sentence: "Limestone is a __________ rock that forms mainly mainly from calcium carbonate derived from the tissue skeletal hard parts of _________ animals and plants."
2. Please define the two words used to complete question one. Hint: a good dictionary is always helpful and educational!
3. The fossils in the gorge prove that this area of Iowa was not always prairie land as it is today, but was in fact millions of years ago, ____________. (A) a tropical rainforest, (B) an arid desert (C) a shallow ocean (D) a steep mountain
4. Study the fossils and identify one of the creatures or plants found in the gorge. Please describe the fossil and what you think its life would have been like 375 million years ago.
Please email your answers to these four questions to me via Geocaching.com when you log your find. Enjoy the area and hope that you learned something new about fossils and the planet that we all share as our home.
If you have time, drop by the visitors center just south of the dam. The hours of operation are Monday - Friday, 8:00am - 4:00pm Saturday & Sunday, summer hours 10:00am - 5:00pm