Fossils Of Rockport
Nearly 350 million years ago during the Devonian period, Michigan found itself at the bottom of a sea near the equator. Thanks to plate tectonics, our poles freezing, glaciers, and many other factors, Michigan definitely is not at the bottom of the sea. Rather, Michigan is home to loads of different fossils from the myriad of life underneath our once tropical seafloor.
Michigan was underwater for millions of years, so many organisms we find are either very early land dwellers, corals, fish, or other underwater organisms. You may never find a dinosaur bone, but you might find something even older…
So how do these fossils form? Well, when Michigan was above water before the Devonian period strong hurricanes and other natural factors killed early organisms. They were buried in swamps and marshes which would later be covered in a tropical sea. That tropical sea held a massive reef with many different species of coral and many organisms a part of a coral ecosystem. As exoskeletons from dead sea creatures stacked on top of each other, their calcium-rich bodies created rock that we Michiganders are very familiar with, limestone.
Limestone is the core reason for this quarry’s existence. Limestone is pivotal in the production of cement, a process mastered by nearby Lafarge. The quarry would be used as a building site for caissons used for the mighty Mackinaw Bridge which is only 75 miles away by the crow.
Now you're wondering, what am I finding now that glaciers and digging have ripped away the surface? Keep your eyes peeled for these types of fossils:
Corals- Corals are formed when prehistoric corals are gradually replaced with agate. Corals are marine animals that form when their skeletons are fossilized and preserved. (Petosky stones are made of coral!)
Horned Corals - Scientifically known as the Rugosa to fossil hunters. They are named for their unique horn-shaped chamber with a wrinkled, or rugose, wall. Their shape makes the Rugosa one of the most well-known and easily recognizable corals. They are an extinct order of coral that were abundant in the Middle Ordovician to Late Permian seas. Some Rugosans reached nearly a meter in length. Like modern corals, rugose corals lived on the sea floor or in a reef. They had tentacles to help them catch prey.
For more information. http://www.michrocks.org/info/horn-coral.html
Petoskey Stones A rock, often pebble-shaped, that is composed of a fossilized coral called Hexagonaria Percarinata. Petoskey stones are fragments of a coral reef that was originally deposited during the Devonian period. When dry the stone resembles ordinary limestone but when wet or polished the distinctive hexagonal pattern of the fossil appears. In 1965, it was named the state stone of Michigan.
Crinoids Let’s just let Hank Green tell you about these creatures that have salt water for blood: Take a Break with some Feather Stars https://www.youtube.com/watch?v=IkSIO2VPM7E&t=152s
Brachiopods Most types of brachiopods are extinct, but there are Brachiopods still alive today. While both brachiopods and bivalves have top and bottom shells, bivalve shells are more likely to be the same, while brachiopods often have different top and bottom shells. A brachiopod attaches itself to a rock using a foot or pedicle. It has arms (tiny tentacles) to catch its food.
For more information. http://www.michrocks.org/info/brachiopods.html
Trilobites - Trilobites are a well-known fossil group of extinct marine arthropods (arthropods are animals who have their skeletons on the outside- like bugs and lobsters). Trilobites had many lifestyles; some moved over the sea-bed as predators, scavengers, or filter feeders and some swam, feeding on plankton. The trilobites were among the most successful of all early animals, roaming the oceans for over 270 million years. For more information: http://www.michrocks.org/info/trilobite.html
FUN FACT: After three species of bats filled two of the conveyor tunnels from the property's old mining operation, grates were constructed to the tunnels to transform the spot into a Bat Hibernaculum. A hibernaculum is where a hibernating animal takes shelter during the winter. The gates prevent people from entering but allow the bat easy access both in and out. The three species calling the tunnels home are big and little brown bats and the tri-colored bat.
FUN FACT: In 2016 Rockport was designated as one of Michigan's Dark Sky Preserves.
FUN FACT: There is a deep water boat launch that can accommodate all sizes of watercraft.[3]
Beware of poison ivy, ticks, and snakes.
Questions:
What type of fossils can you find at Rockport?
Take a photo from on top of the rock pile of the docking area.
What did the company claim as their reasoning for leaving the quarry and moving to Marblehead, Ohio in 1948?
(Last one is on an informational kiosk)
(You can find answers to these questions at Rockport and within the description) Make sure to answer for the log!