This Earthcache is available DURING PARK HOURS ONLY. The park is open from 9:00am until after the last tour leaves the cave. Day use areas are open from sunrise to sunset daily. At the time of publication, there was a $15 charge per adult for the tour of the cave. Cathedral Caverns is an absolutely amazing natural wonder and is definitely worth visiting.
Information on the park can be found at this website.
While visiting this Earthcache, please be respectful of the park rules. When you are identifying the fossils, feel free to take as many pictures as you please but UNDER NO CIRCUMSTANCE should anyone remove or break away any pieces of the rock. Please leave this area just as you found it in order for everyone to enjoy.
Introduction
The idea behind this Earthcache will be to introduce the cacher to the types of fossils commonly found in this area of Alabama. Provided will be a brief description of the geologic history of the area, followed by a description of fossils you may find while visiting.
The posted coordinates should take you to a small outcrop consisting of several large pieces of limestone. This outcrop is located at the northern end of the parking area just beyond a wooden walkway.
To fully enjoy this Earthcache, you may want to consider bringing along some type of magnification tool. A geology hand lens works best, but a simple magnifying glass is sufficient.
Geologic History
The rocks you are looking at are quite typical of this area. There are two main formations found here: the Bangor and Monteagle Limestone. The Bangor Limestone is described as a predominantly light- to dark-gray, bioclastic and oolitic limestone. The lower part contains medium-gray to medium-dark-gray, thin- to medium-bedded, skeletal wackestone containing shaly intervals that are medium gray and weather grayish orange. Light gray to tan, finely crystalline dolomite is locally present. The uppermost part contains medium- to medium-dark-gray, thin- to massive-bedded, oolitic-peloidal-crinoidal packstone and grainstone. The Monteagle Limestone is described as a predominantly very light to medium-light-gray, thin- to medium-bedded, oolitic/peloidal and fossiliferous limestone. The upper part contains an interval of dark-greenish-gray shale.
Both the Bangor and Monteagle Limestones were formed between 359-323 million years ago during what is known as the Lower Carboniferous (or Mississippian) period. The Carboniferous is often split into two divisions, the Mississippian and the Pennsylvanian; in the United States the break in the geologic sequence is so sharp that each division is commonly considered an independent period.
During the Carboniferous period, Alabama was covered by warm, shallow seas, which contained a variety of animal and plant life. Over the course of millions of years, these plants and animals died and were covered by sediments. These sediments were eventually lithified to form the limestone rocks you are now looking at.
The Bangor and Monteagle Limestones contain many types of fossils including crinoids, corals, stromatoporoids, molluscs, brachiopods, blastoids, bryozoans and trilobites.
While I was here, I quickly identified two types of fossils. A description of each of these fossils can be found below:
Crinoids
Crinoids are marine animals that make up the class Crinoidea of the echinoderms. Crinoidea comes from the Greek word krinon, "a lily", and eidos, "form".
Crinoids are neither abundant nor familiar organisms today. However, they dominated the Paleozoic fossil record of echinoderms and shallow marine habitats until the Permo-Triassic extinction, when they suffered a near complete extinction: many Paleozoic limestones are made up largely of crinoid skeletal fragments.
Stalked crinoids, or "sea lilies", lived attached to the bottom, and filtered food particles from the currents flowing past them. The extant Crinoids are the only remaining attached suspension-feeding echinoderms. This makes them an important group for Paleontologists studying the numerous extinct attached suspension-feeding echinoderms because they have only the living crinoids to examine as an example of this ancient mode of life. The living stalked crinoids mostly inhabit deep water and are therefore difficult for the average underwater enthusiast to observe.
Crinoids can be pretty easy to identify if they are large enough. If they are face up, just look for a circular shape with a small, dark area in the center. If they are on their side, they look very much like a roll of coins, or a stack of coins. Just look for a cylinder shape with ‘ribs’ along the side.
Rugose Coral
The Rugosa, also called the Tetracoralla, are an extinct order of coral that were abundant in Middle Ordovician to Late Permian seas.
Solitary rugosans (e.g., Caninia, Lophophyllidium, Neozaphrentis, Streptelasma) are often referred to as horn corals because of a unique horn-shaped chamber with a wrinkled, or rugose, wall. Some solitary rugosans reached nearly a meter in length. However, some species of rugose corals could form large colonies (e.g., Lithostrotion). When radiating septa were present, they were usually in multiples of four, henceTetracoralla in contrast to modern Hexacoralla, colonial polyps generally with sixfold symmetry.
Rugose corals have a skeleton made of calcite that is often fossilized. Like modern corals (Scleractinia), rugose corals were invariably benthic, living on the sea floor or in a reef-framework. Some symbiotic rugose corals were endobionts of Stromatoporoidea, especially in the Silurian. Although there is no direct proof, it is inferred that these Palaeozoic corals possessed stinging cells to capture prey. They also had tentacles to help them catch prey. Technically they were carnivores, but prey-size was so small they are often referred to as microcarnivores.
Examples
Crinoids
Rugose Coral
To qualify for this cache, send a private email to the cache owner with the answers to the following:
1. The GC code and name of this cache.
2. Describe the outcrop: How many rocks make up the outcrop? What color are the rocks? What size are the grains in each rock?
3. Did you find any fossils? If so, what did you find? What size were the fossils you found?
4. What is the approximate length of the northern-most rock in the outcrop?
5. OPTIONAL: If you don't mind, let me know if you decided to tour the cave. The cave tour is certainly not a requirement, I would just like to know.
There is no reason to wait for a response confirming your answers. If you feel you've satisfied the requirements, go ahead and log your find. It is my goal to respond to every email but if you do not send your email address, I will not be able to respond.
Congrats to BAMA1986 and Gray Bat for the FTF!