Connecting the environment of the ancient past with the natural and cultural history of yesterday and today.















 

 


The Collecting Piles

Located behind the Interpretive Center, next to the far side of the parking lot.

Waldron Shale pile

Visitors look for fossils in the Waldron shale collecting pile.

What is the Waldron Shale?

Named after the town of Waldron in Shelby Co., Indiana, this rock unit (called a 'formation') started as mud on the bottom of the sea about 423 million years ago, during the middle of the Silurian Period. In Clark County, Indiana, it consists of shale (made of clay) and thin, irregular beds or lenses of limestone.

Paleontologists investigate the Waldron shale at a Clark Co., IN quarry

Paleontologists investigate the Waldron shale at a Clark Co., IN quarry

What to look for:

Fossils – shells of brachiopods (abundant), snails (common) and clams (uncommon), trilobites (common), crinoid stems (abundant), crinoid bodies (common), corals (common), and trace fossils (abundant). There are many more fossils than the fossil identification page below show. The best time to look for fossils is after it rained. Many of the fossils are easier to see.

Waldron Shale Fossil ID Pages

Minerals – pyrite (fool's gold) and calcite (white crystals usually inside fossils) are both common.

Helpful tools:

Digging tools – big screwdrivers, small shovels or hand trowels

Water bottle – to clean the rocks to see the fossils better

Toothbrush – to scrub the rocks with water to see more fossils in the rock

 

Jeffersonville Limestone dirt pile

Digging in the dirt pile.

What is the Jeffersonville Limestone?

Named for exposures on the east end of the Falls in Jeffersonville, the outcrops were flooded when the river was dammed in the 1920s. This limestone makes up the bulk of the fossil beds that are protected at the Falls of the Ohio. However, outside the park, collecting is possible, although there are few exposures that are easily accessible. As a result, we bring in material from a rock quarry.

The pile consists of red clay – a sub- soil – that was formed by the decomposition of the Middle Devonian (390 million year old) Jeffersonville Limestone. Fossils frequently become petrified (replaced by quartz) and accumulate in the red clay.

Corals in the soil formed by decomposing Jeffersonville Limestone.

Corals in the soil formed by decomposing Jeffersonville Limestone.

What to look for:

Fossils – shells of brachiopods (common), snails (common), crinioid stems (abundant), corals (common), and sponges (uncommon). Other fossils rare. Note: Chert in usual shapes may be found. They are not usually fossils, although may have fossils in them.

Minerals – quartz in tiny crystals may be found in some of the chert-rock.

Helpful tools:

Digging tools – a small shovel or hand trowel to dig into the dirt will be very useful. This clay is very compact from people standing on it.

Water bottle – to wash the rocks (with the tooth brush) so you can see the fossils better

Toothbrush – to scrub the rocks with water to see more fossils in the rock

 

Mineral Collecting pile

Collecting minerals in the mineral pile.

To keep things exciting, we bring in truck load of rock from the fluorite mines of Hardin County, Illinois.

What can I find in this pile?

There are four common minerals, some occur as crystals.

Fluorite is a purple and yellow crystalline mineral composed of calcium and fluorine. It is an important mineral used in U.S. industry to make steel, aluminium, and a zillion chemicals! If it sounds familiar, perhaps you have used toothpaste with fluoride in it. That comes from fluorite!

Calcite is a white crystalline mineral composed of the same material as limestone (calcium). It is commonly found a crystal fragments in the shape of a rhombohedron (it has two diagonal edges instead of square ones). This mineral is used to make lime and other chemicals.

Barite is a heavy white mineral made of barium that, at first glance, looks like a lump of chalk. The crystals are usually intergrown and very tiny, so it looks like a solid white rock. The density gives it away – it is very heavy for its size. Unlike calcite, it doesn’t fizz with vinegar. Barite is used to drill oil wells and in several medicines.

Sphalerite is the brown to reddish-brown crystalline material composed of zinc. It is very sparkly, reflecting light easily. Crystals can be the size of a grain of sand or as big as your thumb. This mineral is used to make a lot of different things, from poison ivy anti-itch crème to car batteries!

Mineral Identification Page

Helpful tools:

Digging tools – big screwdrivers, small shovels or hand trowels

Water bottle – to clean the rocks to see the fossils better

Toothbrush – to scrub the rocks with water to see more fossils in the rock

We turn the piles several times each year, to expose new material.

 

Created November 15, 2010, updated July 1, 2013