2021 JGC Theodore Roosevelt Area EarthCache

JaxParks and Visit Jacksonville are proud to bring you this cache as part of the 10th Annual Jacksonville Geocaching Challenge. In each JGC Geocache, you will find a stamp attached to the log book. Simply stamp your 2021 Jacksonville Geocaching Challenge Passport in the appropriate space as you visit each geocache. When you have collected all ten stamps, you qualify for one of the 150 limited edition, uniquely shaped tokens!

For more information on the 2021 JGC Challenge, please visit the Jacksonville Geocaching Challenge website (link shown below) to download the official 2021 JGC Passport (which you will need to be able to print), review the rules, and learn how to obtain a token. The website also has an electronic brochure with details of the JGC Challenge which you might find handy as you explore Jacksonville’s great park system and other interesting places in Duval County.

While enjoying the chance to get outside with your family to find the 2021 Jacksonville Geocaching Challenge caches, please follow all CDC, State of Florida, and Duval County guidelines. Wear your mask when appropriate, practice social distancing, wash your hands for twenty seconds frequently, and use hand sanitizer when handwashing is not convenient.

Community COVID guidelines will be implemented as appropriate.

SHELL MIDDENS - HUMANS AS ANCIENT GEOMORPHIC AGENTS

Geomorphic agents are forces that move material and sediments from one place to another to change the earth's surface. There are two types of geomorphic agents: endogenic and exogenic. Endogenic agents are forces that come from within the earth and are primarily earth-building forces. Some examples of endogenic agents are earthquakes, volcanoes, landslides, and the faulting and folding of the earth. Exogenic agents are forces that come from the earth's exterior or from the atmosphere and are more earth-deterioration forces. Examples of exogenic forces are water-tides, waves, glaciers, wind, and most importantly, humans. Humans are the greatest geomorphic agents on the planet. All other endogenic and exogenic forces combined over the millennia do not add up to the amount of change that humans have done in the last 5,000 years. The shell middens found at the Theodore Roosevelt Area of the Timucuan Ecological & Historic Preserve were made by ancient people and have significantly changed the environment.

What is a shell midden?

A shell midden is a geo-archaeological feature that is made mostly of mollusk shells. The name "midden" comes from the Danish word kokkenmoddinger, which means "shell heaps." The shell middens found at the Theodore Roosevelt Area are old refuse sites from early peoples, ancestors of the Timucua people, who lived during the Archaic era (10,000-3,000 years Before Present) in Florida. Most of these early peoples were nomadic, meaning they would wander from place to place following food sources and seasonal changes. They were fishers, hunters, and gatherers, who ate oysters, fish, game, and vegetables they cultivated. Many peoples returned to the same places season after season. The midden sites would be a marker to indicate hunting grounds and seasonal home sites.

What is found in a shell midden?

A shell midden consists of broken oyster, snail, crab, mussel, and clam shells, compost, broken pieces of pottery and tools, bones of other animals, and discarded, recycled, or unwanted items. The content would differ depending on what is available in the area of the midden and what the midden was used for. Some middens were used for rituals and contain less organic materials. Other middens were used for burials and contain human remains. The middens found at the Theodore Roosevelt Area are processing remains: areas where mollusks were processed immediately after collection and stored for later use at other locations.

Where can shell middens be found?

Shell middens are abundant in Florida from Cape Canaveral northwards. The early peoples of the Archaic and Orange periods, who were the ancestors of the Timucua people, moved up and down the coastal islands following food sources. They placed their middens strategically, usually at the edge of a body of water on the intercoastal side of the sea islands. The middens are usually near food sources (such as a marsh), out of the way of normal traffic, and somewhat out of the way from sight and smell. There are four documented shell middens inside the Theodore Roosevelt Area covering over 25 acres of land.

How are shell middens formed?

Shell middens are human-made over a long period of time, often over centuries. Season after season, generation after generation, the early peoples would collect their refuse into piles. A circular or semi-circular design with smaller circles radiating off the main circle was the distinctive pattern used in this area. Middens can be quite large, some of them covering over a tenth of a mile. The depth of the midden is variable as well, depending on how long the midden was in use. The middens here at the Theodore Roosevelt Area are presently 25 feet deep. They were once much larger, but over time they have been compressed and excavated. The early peoples not only used the middens as a refuse pile, but also as a way to make high ground to use during storms and to observe the surrounding areas.

When were shell middens formed?

Most shell middens in Florida were in active use from 4,000 to 5,000 years ago. The four middens here have been dated to about 2,500 years ago. (To put this into perspective, the pyramids at Giza were being built during this time.) The shell middens were added to as the peoples gathered and ate the many shellfish found in the area. Very slowly over time, the shells compacted and weathered, and the middens began to decrease in stature. Humans also have used the middens as a source of material to make other things, such as roads and tabby (bricks made of oyster shells). There is evidence the middens at the Theodore Roosevelt Area were mined for shells in the early 1900's for road bed foundations.

How do shell middens change the geology of the environment?

Humans have been changing the earth since they have been in existence. Each time a human moved a rock or shell, or planted a garden, the geological environment was being changed. Shell middens change the environment by making flood-free land where there was once only marsh. Shell middens delay the rate of decay. The calcium in the shells degrades very slowly. This leaves a high proportion of organic evidence (food remnants, organic tools, clothing, and human remains) in the midden, a treasure trove of information for archeologists. Shell middens enrich the soil with nutrients. Nitrogen, calcium, potassium, and manganese are all in higher concentrations around the middens due to the shells that make them. This gives the soil increased alkalinity and has allowed some rare pioneer plants to take hold. Some of the more rare plants found on middens sites are the peperomia (Peperiomia obtusifolia), Godfrey's wild privet (Forestiera godfrei), wild coffee plant (Psychotria nervosa), and milkvine (Matelea floridana). Shell middens also encourage maritime hardwood hammocks to form.

Shell middens have been in Florida for thousands of years and have changed the geological environment here in the Theodore Roosevelt Area. Ancient peoples piled shells to dispose of refuse, but in doing so, they reshaped the land as well. They made flood-free land from marsh, changed the soil composition, and also changed the types of plants found within the middens.