Most local history presentations cover about 300 years – maybe a little more or less. But at the March program of the Town of Lloyd Historical Preservation Society, Professor Steven Schimmrich took his rapt audience back 400-plus million years to a time when – to the surprise of most – what is now the Hudson Valley was located about 20 degrees south of the equator.
But before he went back 400 million years, Prof Schimmrich, professor of geology at Ulster County Community College, began his presentation on The Geology and History of Rosendale Cement with the more modern history of cement itself, as a building material throughout the world. The ancient Babylonians mixed clay with water, which worked fine, he explained, in a dry climate. The Egyptians used gypsum, what we call plaster of Paris, which also worked well in the dry Sahara region.

Early Cement
Eventually, “Someone, somewhere, decided to take a piece of limestone and cook it,” Prof. Schimmrich said.One component of limestone is calcite, a product of marine invertebrates that lived on the sea floor for long periods of time, eventually hardening into limestone deposited on dry land as the seas rose and fell.
“When you heat up limestone,” explained Prof. Schimmrich, “it breaks down the calcite into CO2 gas, and you are left with quicklime.” The Romans added pozzolana, a volcanic ash material, to quicklime, making a wonderful concrete. But over the years, that technology was lost in Europe. In 1824 a new technology solved the problem. Adding to limestone a mixture of ingredients, including clay, made a very durable cement. Different proportions created cement with different strengths, allowing builders to choose what best met their specific needs.

“The advantage today,” Prof. Schimmrich pointed out, “is that you can go to Lowe’s and pick up the very specific kind of cement you want.”
But the search for a better cement went on. By the late 1700’s/early 1800’s. People realized there was a type of rock, scattered in spots around the world, that when cooked, ground, and mixed with water, was a natural cement.

Discovery of Rosendale Cement
One of those scattered spots turned out to be in the Hudson Valley, which by that time had long since moved up to its current home far north of the equator.
In the early 1800’s, America was growing and the need to move products long distances was growing too. Railroads were not crossing the country yet, so rivers were heavily relied on for moving goods. But rivers didn’t go everywhere, and the need for canals became evident in New York State. If you could get your goods to the Hudson River, you could get them down to New York City. So it was a choice between piling up goods in horse-drawn wagons, or building a canal.

Canals needed locks, and locks needed concrete. Construction of the Erie Canal to cross New York State began in 1820. Near Syracuse the builders found a rock unit that made a nice natural cement. Using that cement, the Canal opened in 1824.

History of the Rosendale Cement District
Next, some of the same engineers went to work on the Delaware and Hudson (D&H) Canal. They thought they would have to get cement from Syracuse, but right along the canal’s route, in High Falls, near Rosendale, they discovered a rock that when burned made a great natural cement, saving them a lot of money. The best part: they could use it to build the canal, and then they could use canal boats to ship the cement elsewhere as needed! Thus began what was for many years the region’s primary industry.
The real history of what geologists call the Rondout Formation, began 418 million years ago 20 degrees south of the equator. It was located next to the Taconic Mountains, now rolling hills but back then as high as the Rockies are now. In an aside, Prof. Schimmrich pointed out that much of the pebbly ground that washed out of the mountains as sea levels rose and fell now covers parts of Minnewaska State Park and Mohonk Preserve, so anyone wanting a walk back in time can hike on it there.
In the millions of years that sea level rose and fell (and the region moved northward), layers of different types of rock created the Rosendale Cement District. Two layers of dolostone, which makes natural cement, separated and topped by limestone, which as Prof. Schimmrich had already pointed out, needs additives to become cement, can be found around Rosendale, where man-made caves (mines really) and kilns added onto the hills create a landscape of arches looking like doors into the hearts of the hills. The caves were created as the miners took out the dolostone leaving a ceiling of limestone held up by pillars, left there for that purpose.

The lowest and oldest level is called Rosendale dolostone; the middle level is Glasco limestone, which Schimmrich dubbed useless (at lease as compared to the other levels); and the upper level is known as Whiteport dolostone. Topping it all is another level of limestone.
One interesting feature of the Rosendale Cement District is that the levels are not all horizontal, but have been bent and broken by the varying sea levels as they rose and fell. With each layer a different color, these folds and faults can easily be seen inside the mines.
Prof. Schimmrich showed a slide of a double-decker mine, with the Rosendale and Whiteport dolostone mined out, leaving rooms and passageways under and over the layer of Glasco limestone.
There is one mine that is open to visitors: the Widow Jane Mine, big enough to hold public events and rock concerts. “I don’t really know how big it is,” the professor said. Of the original mine, 80 percent is currently under water.
“Some of the mines are large and some are small. Some you could drive a pickup into,” reported Prof. Schimmrick. He admitted to getting lost the first time he went into a big one. “It’s a little spooky if you are alone,” he said. “It’s pitch black. You hear water dripping, and after awhile you hear footsteps.” These aren’t necessarily imaginary. “I have actually run into people there,” he added.
“But what really scare me,” he went on, “is seeing cedar pillars holding up big rocks. In some areas the roofs are delaminating.” The danger is mixed. Some parts are very safe, but in some parts you want to breathe shallow and tread lightly. There are collapses. Last year the front face of a mine fell down.
“The mines have been of interest to geologists for 100 years,” he said, showing a picture of geology students there from Princeton many decades ago. They are all dressed in suits and ties. “They dressed better than geology students today,” he added with a grin.

The Kilns
The smaller arched entrances that appear to lead into the hills are actually the fronts of the kilns where the limestone was burned into cement. Each has an opening on the top of the hill, providing a chimney. At one time the kilns had small buildings attached to them, or at least roofs over the openings. Prof Schimmrich reported that he is working on a kiln inventory with photos and measurements.

Cement Companies and Workers

There were once well over a dozen cement companies operating mines in a stretch of land only 18 miles long and about a mile wide. Now their buildings are pretty much gone, and the grounds returned to trees, where once, a 100 years ago, the trees had all been cut down and the areas by the river was all industrial. There are still remains of tracks going into the mines and on top of the kilns. Today, the professor said, you might find rocks piled up and bits of rusting materials, but the landscape is pretty much natural.
Most workers were immigrants, he said, mostly Irish, with some local farm people also.
Pictures showing children are not photographs of kids visiting their fathers. The kids are workers, and the work was hard. There was no workers’ compensation, no OSHA, no retirement benefits, and no insurance. They breathed cement dust for 10-hour shifts, with no respirators.
Later came electricity and hydraulic drills, but older pictures show horse-drawn carts – or maybe oxen. He noted that the animals did look big for horses.

More Facts

Prof. Schimmrich listed a number of other facts about the Rosendale Cement District:
• In the 1840s, there were 13 companies, owning 16 cement works producing 600,00 barrels of cement per year.
• In the late 1800s, the Rosendale District accounted for 50 percent of the country’s annual production of natural cement.
• In 1890, the District produced five million barrels of natural cement.
• By 1910, the natural cement industry tanked, due largely to Portland Cement’s ability to tailor its product to customer needs.
• The last big project was the New York State Thruway.
• The last Rosendale cement company closed down in the 1970s.

Natural Cement’s Legacy
You can still see the products of the Rosendale cement industry in important structure and monuments, for example:
• The Brooklyn Bridge, which depends upon Rosendale cements solidity under water,

• The base of the Statue of Liberty,
• The bottom half of the Washington Monument,
• Fort Jefferson in Florida.
New Uses for the Mines
As well as the events, such as drumming concerts that take place in the Widow Jan Mine, the mines of Rosendale have found other uses, such as growing mushrooms and underground records storage. They have provided water for whiskey production too, although the professor stated firmly that the brand called Widow Jane does not used water from the Widow Jane Mine.
And bats love the mines, using them for habitat. Either sadly or happily, depending upon your point of view, Prof. Schimmrich says they will all be dead soon, wiped out by the white mouth fungus that is killing most of the bats in the area.

Upcoming TOLHPS Program
The Town of Lloyd Historical Preservation Society regrets to announce that, in consideration of its audience and speaker, it is postponing the upcoming April program, originally scheduled for April 6. The rapid spread of the Coronavirus has led to the recommendation that the public avoid large gatherings, making this a prudent move. The Society will announce future plans as soon as possible.