My Backyard and a Little Beyond

In Florida, one does not have to travel far to find fossils. I started in my own backyard. There was a serious draught in effect when I first moved to Florida in June of 2001. The pond behind my house was at a record low level of water. Houses had been built on a small ridge of earth created by the contractors. This would prevent easy flooding during the numerous thunderstorms that we experience in Tampa.

A Few Clams

Below the added surface, in the banks of the now water-thirsty pond I found a few fossil clams. The bivalue mollusks were not museum quality but nevertheless, I was excited to know that I could find fossils so close to my house. The original shell is gone but left behind were shell casts comprised of calcite. Not surprising that they are made of calcite since limestone, a calcite based stone, is commonplace in Florida.

Alligator Feeders in My Backyard

By the way, one has to be alert for alligators at all times when hunting fossils near or in water. Here a small alligator was watching me take a picture of my backyard. Feeding alligators is not very wise, besides it is against the law. Just avoid being lunch and you will be fine.

Cross Creek Road - Tampa

Anywhere construction occurs, fossils have a likely chance of being exposed. I have learned to stop at all accessible piles of earth stacked by the roadside from some excavation. Ponds are a common landscape item in Florida housing complexes. The earth extracted from these ponds may be used to elevate homes or if the pond is more like a small lake in size, the dirt will be piled nearby for future use. For example, this block square plateau of dirt was located on Cross Creek Road in Tampa. The mound of dirt provided coral heads of agate, jasper and chert. The colors were excellent.

Tampa is famous for coral with agate centers, therefore, expect to find coral with agate in the Tampa area. The agate's fortifications and colors are gorgeous. The pieces I collected at this site were both large and small. Some of these pieces fluoresced a light yellow-orange color at approximately 3660 Å.

Which Branch to Take?

We found numerous pieces of coral that had been replaced with agate. The coral branches had not been exposed to the abrasiveness of rivers, beaches and wind. Therefore, they felt very rough. The coral pieces came in various forms. The two most common types were branches and flakes. The branches hold the possibility of fortified agate patterns inside but their size precludes much lapidary potential. The longest branch, with a slight gray color, illustrated is approximately 70.3 millimeters long and the shorter one is approximately 66.5 millimeters long.

Little Mouths

The coral branches were often hollow tubes. The ends of the branches remind me of a worm's mouth. The three illustrated, notice the white one's end (it is approximately 42.5 millimeters long).

There's Agate in Those Mouths!

Most branches had some agate showing on one of their ends (illustration of coral branch's agate end is approximately 11.4 millimeters). All the coral branches were lying on top of the ground.

Coral Flakes for Breakfast

The coral flakes were also made of agate. They were most likely the thin walls of coral hollows. I assumed this because they all were slightly curved in shape not unlike a piece of an orange peel. Some exhibited a botryoidal surface. One piece's botryoidal surface was coated with a dull white calcite (approximately 44.3 millimeters by 52.5 millimeters).

Spotted Owls They Are Not

Some of the coral flakes had white spots on the botryoidal surface (the longest piece is approximately 54.3 millimeters by 22.8 millimeters).

Now We're Talking!

One piece was geode like and had dark colored botryoidal agate inside with edges of fortified multicolored agate lining the edges. This I will make into a cabinet specimen by sanding the edges and polishing them (approximately 86.4 millimeters by 56.0 millimeters).

Happy as a Clam

Numerous fossil shells were present but only a few were not broken or deteriorated. The larger white ones were from bivalue mollusks (clams). Small clams were even more abundant. Unlike non-fossil shells, fossil shells are white and void of other colors. There were also gastropods. Some fossil shells that had been replaced with calcite were discovered. The bivalve (clam) illustrated is approximately 35.7 millimeters wide by 28.6 millimeters wide and is in a calcite matrix. This is the material that eventually may become limestone and then marble if placed under extreme pressure for millions of years.

Mounds like this appear all over Florida. Whenever you see one and it is not on private land, posted or guarded, take a few moments to check it for fossils. However, it is not a good idea to enter any property, posted or not, without first securing permission.

        by Bill Hoefer