Greatlakes Beach Facts Greatlakes Beach FactsBeaches are accumulations of sand, gravel or pebbles which separate land from water.
Most Michigan sand is rock gathered in Canada by the glaciers and ground to sand as the ice moved southward, then washed out by streams from the glaciers. Only sand of the dunes is finer than beach sand. Beach sand grinds no finer because a little water surrounds each grain, cushioning it against grating against neighboring grains as the waves churn up the beach. Pebbles on the other hand, last no longer than about a year on the beach before the beating surf grinds them into grains of sand!
Great Lakes sand is mostly white because over 90 percent of the Great Lakes sand is silica, a pure form of quartz that is very hard. Feldspar, a common mineral in the area, dissolves into clay that washes out of the sand settling out in the lake. It can be seen in the sand as pink or gray flecks.
In a handful of sand you might find garnet, magnetite, topaz, even sapphire. Occasionally sand especially in the U.P., has flecks of copper, gold and silver in it. All to often the flakes of "gold" are actually mica or pyrite -- fools gold!
Sand a magnet picks up...
You will also find black granules in the sand that are often an iron ore called Hematite. Sometimes when the waves roll hard you can see bands of it form on top of the sand near the water. If you use a magnet, you can pick up this iron ore. If you look at the black material through a magnifying glass, you can see they have triangular faces (edges). Sometimes these perfect triangles join and form into an octahedron (eight sided crystal).
Beach glass is glass from things like broken bottles or glass dishes. The pieces of glass are washed around in the waves and ground down by the sand. They look like smooth frosty clear rocks. You can find them in white, green, brown, and if you are lucky blue, purple and other colors! Eventually the waves will grind the glass down to sand. That's funny because they melt down sand to make the glass in the first place.
The bedrock under all the gravel and layers of sedimentary rock here on our beach is over 1,000 Million years old! The sedimentary rocks like sandstone formed about 500 Million years ago and carry evidence of creatures that lived in the ancient seas.
At one time this area was under a warm salt-water sea. Dinosaurs wandered the area and there was a coral reef out in the water with all kinds of fish and creatures around. The coral reef was eventually buried with silt and died as the area became colder. Evidence of it, along with parts of the sea creatures can be found in the rocks on our beach.
A fossil can be evidence of any form of prior life. Sedimentary rocks make up the majority of the pebbles found on Michigan beaches. In many of these rocks there are great fossils! Many of the actual parts of the reef or fish have been preserved through a fossilization process called replacement mineralization. Calcite or silica takes the place of the original animal or plant and this petrifaction (turning it to stone) preserves the details for you to see!
The Petoskey stone is the most famous Michigan fossil. It was originally a type of colony coral from the reef. A colony coral is a type of coral that had many little creatures living tightly together in a colony. The Petoskey's colony was made up of hexagon (six sided) shaped units and they form a pattern in the rock that is easy to pick out, especially when it is wet. Look for a rock with hexagon shapes touching each other all over the rock. Each hexagon is about as big around as a pencil eraser.
If you find rocks with a design of circles much smaller (about the size of a BB) it is a colony coral called "Honeycomb coral" and looks like a honeycomb. Also, look for "Chain coral" that looks like rocks with very little chains going across the rock that you can just see the links in.
One coral that lives all by itself as a "Solitary Coral" is a Horn Coral. These 2 - 4 inch horn shaped creatures stood on the reef with their big end up. They had stinging tentacles that caught their food as it floated by. Now you can see parts of the horn imbedded in rocks and sometimes find a whole horn, which has eroded out of the rock. They have thin lines running from tip to stem packed closely together.
The best fossils we find sometimes on our beach and sometimes at the bottom of our stream (where there is a clay layer that was the bottom of the warm water sea) are Brachiopods. They look like little winged creatures that were prehistoric clamshells. They are from 1 to 2 inches from tip to tip and have thin lines running from the front edge to the back edge of their shell.
Crinoids or sea lilies were spinney skinned marine animals that scavenged of the sea bottom. Many of their fossils look like 1/4 round 1/2-inch long "stems". They are made up of many little disks all stacked up.
Fresh water clamshells or mussels grow to several inches long and can be found on our beach. They have two equal size shells and a hinge in between. They are iridescent mother-of-pearl on the inside and brown on the outside. Back in 1890, they made buttons out of these shells.
Sometimes you can find Snail shells on our beach that are like little spirals (narrow cone shapes) about 1/2 inch long. They can be a variety of colors and are pretty when you look closely.
A new kind of shell that you can find on our beach is the Zebra Mussel. They are like a clamshell, only long and narrow with the hinge at the narrower bottom end. They are 1 - 2 inches long and have zebra stripes.
Scientist thinks the mussels came from Europe in 1985 by hitching a ride on an ocean freighter. They were probably dumped in the Great Lakes with the ships ballast water. Zebra Mussels like their new home so well they are multiplying out of control. They can live up to five years and one female can produce up to 50,000 eggs a year. After they are born the little mussels must find a rock to attach to within 10 days or they will die. They like to live in places where fresh water comes into the lake. Their favorite homes are water intake pipes (which they clog) and places where streams empty into the lake. They eat a lot of plankton, which usually clouds the water in most lakes. Baby fish in the area (who like plankton too) die because they have nothing to eat. Without plankton, the water becomes so clear that the seaweed gets to much sunlight and grows out of control, clogging the lake and changing the balance of oxygen.
They also have sharp edges that can cut your feet. So far only a few animals eat them and we have found that bleach will discourage them from coming too close. We saw them for the first time in 1992 here at camp. There are now millions of them near the mouth of our stream! So far, there are none in our swim area, but they are spreading fast!
Lake Huron has many shipwrecks and there is one buried right here in the sand under our beach at Camp Cavell. She was a wooden two masted sailing schooner named the "Kate Richmond" built in 1855 in Cleveland. With a length of 127 feet and a width of 26 feet she was a fine sailing ship in her day. Just before she sank she was working in the local area transporting goods between the local cities here in the thumb. The lakeshore road was almost impassible in those days so everyone sent their goods by ship.
The Kate was caught in a winter storm and went down on December 5th 1885. Her crew escaped in her yawl. This is not the first time the Kate had sunk. In 1869 she spent two years on the bottom of the lake after sinking in a storm and was rebuilt in 1866. Efforts were made to try and salvage her again in 1886, but this time she was too badly damaged. She was later burned. The timbers of her wreck extend from the break-wall to the dining hall under our beach.
You are welcome to dig for the Kate near the center of the beach. You should find her timbers only about 3 feet down. Watch out for large iron rods that held her timbers together. If you look in the photo at the top of this article you can see part of her hull that was showing when the lake water was high and it washed away the sand.
A second shipwreck that is near camp is out about 4 miles out in the lake, in 80 feet of water. Sometimes if you look out a little to the left of our beach area you can see dive boats anchored near her. Her name was the Regina and she was a 250-foot Canadian steamer (one of the first all steel freighters). The Regina was carrying a cargo that included hardware, champagne, whiskey and dishes.
She went down in the great storm of 1913 with all 15 hands aboard. The storm was the biggest ever recorded on the Great Lakes and claimed 250 lives and 13 big ships. The winds were of hurricane force and the waves over 35 feet high. When the Regina went down no one knew where she sank and she was lost for many years.
Our past camp superintendent and two of his friends finally found her several years ago. Everything is still aboard as it had been and she is sitting upright on the bottom and now has many visitors as divers are allowed to dive on the ship.
Guide to Mich. Fossils. DNR, 1962 Geo.Survey
Fall Beachcombing. Suzanne Tainter, MISHU-SG-78-305
The Great Lakes Shipwreck File: Total Losses of Great Lakes Ships, 1679 - 1999 by Dave Swayze
Lake Huron Water Levels to Continue Low Trend!