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Lake Monongahela?
Pittsburgh's prior location on the equator?
Never heard about that?
Neither had the bicyclists who accompanied Albert Kollar last month (Nov. 22) on a 24-mile geology and history ride on the crushed limestone surface of the Montour Trail.
Kollar, 57, of Turtle Creek, a geologist at the Carnegie Museum of Natural History and veteran bicyclist, discussed the lake and Pittsburgh's once-upon-a-time location on the equator while leading a tour organized by Venture Outdoors.
As the bicyclists stopped on the 967-foot long concrete deck of the wind-swept McDonald Trestle in Washington County, Kollar told them about nearby oil fields that at one time were second only to Titusville in oil production in Pennsylvania. The fields produced 12 million barrels of oil from August 1891 to August 1892.
The surrounding landscape, he said, had once had been under Lake Monongahela. The ancient lake was huge. It was bordered by what now is Ellwood City, Kittanning, Latrobe, Uniontown, Morgantown and Clarksburg, W.Va., and East Liverpool, Steubenville, Wheeling and New Martinsville, Ohio. The lake's "beaches" included the tops of what are now Mount Washington, Monument Hill, Troy Hill a stretch from Oakland to Homewood, Regent Square, Kennywood Park and Coraopolis.
Kollar said the bedrock geology along the Montour Trail is dominated by rocks -- coal beds, sandstones, fresh water and salt water limestone and siltstones-shales -- that were formed in the Late Pennsylvanian and Early Permian Periods, a mere 300 million years ago.
"At that time in earth history, the Pittsburgh region was situated at the equator [where] the climate was hot, tropical, wet and seasonal," he said."These rocks were deposited along a broad coastal plain similar to what the southern United States looks like today."
PG MAPAt one time, all the streams in Western Pennsylvania and West Virginia flowed into the Gulf of St. Lawrence and then into the North Atlantic.
After the region was uplifted during the formation of the Appalachian Mountains 250 million years ago, four ice advances and retreats reached the mid-latitudes of the United States.
Those advances and retreats, which began 2.6 million years ago in the Arctic region of Canada, "eventually formed Lake Monongahela and in areas throughout the region left flat areas or terraces, including the Montour Trail," he said. "Eventually a new river course was formed displacing the primary river, the Monongahela, with the Ohio River that drains to the Gulf of Mexico."
And the Allegheny River?
That waterway, once three separate rivers that flowed northwest, became one continuous river when the upper and middle rivers breached their divides to join the lower river.
"Fascinating," said Stan Sattinger, 69, of Bethel Park, the founding president of the Montour Trail Council. "I've always wondered how these valleys got here."
"You can learn a lot on a bike tour," said Robert Habegger, 49, of Hampton, a veteran tour guide for Venture Outdoors. "The geology, [three] trestles and [two] tunnels on this section of the trail really make it special."
Agreeing with that assessment were Fran Monaghan of Squirrel Hill and his six year old son, Rory, Mark Miller of Aspinwall, Marilyn Marsico of Aspinwall, Ashley Rieser of Lower Burrell, David Sze of Collier and Annette Slezak of Penn Hills.
The tour stopped at the 235-foot long Greer Tunnel for lunch, a popular spot that has a few benches and easy access to Chartiers Creek. The tunnel and bridges on either side of it were built in 1913 so the Montour Railroad could serve new coal mines east of Imperial.
Enjoying the day with the tour riders were walkers, joggers, runners, birders and dog owners with their canines on a leash.
At Venice, the group dismounted, placed their bikes in a U-shaped track and walked it down a flight of steps. They crossed Rte. 50, walked their bikes up a short hill and got back on the trail. A bridge one day will make that interruption unnecessary. Hopefully, the steps will remain to reach Aunt BB's Diner, a welcome addition to the community.
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