Round Top Geology Historical

Round Top Geology Historical (HM1T90)

Location: Hancock, MD 21750 Washington County
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Country: United States of America
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N 39° 40.629', W 78° 13.597'

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Chesapeake and Ohio Canal National Historical Park

The layers of red sandstone, siltstone, shale and limestone beneath the limekilns on the other side of the canal are like pages in a book to geologists. These folded, even rock layers indicate that millions of years ago this area was covered by a shallow sea. As the waters swelled and retreated, due to climatic change and tectonic plate movement, the colorful layers of sedimentary rock were exposed.

The rocks also tell a story of a violent collision between the North American and African tectonic plates over 240 million years ago—the same collision that formed the Appalachian mountain chain The force of the impact caused the rocks to fold and fault, creating the anticline or upward arch in the rock layers visible under the kilns.


Canal engineers discovered high calcium limestone in Round Top during construction in the 1830s. By 1838 Round Top Cement Company began mining operations here. This photograph shows an anticline after the layers of limestone were removed.

Down the towpath 200 yards to your right is Devil's Eyebrow, a hollow that formed when the soft, lower layers of calcium-rich rock eroded leaving the more resistant harder layers of the anticline intact.
HM NumberHM1T90
Placed ByNational Park Service, U.S. Department of the Interior
Marker ConditionNo reports yet
Date Added Monday, July 25th, 2016 at 9:03pm PDT -07:00
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Locationbig map
UTM (WGS84 Datum)17S E 737863 N 4395602
Decimal Degrees39.67715000, -78.22661667
Degrees and Decimal MinutesN 39° 40.629', W 78° 13.597'
Degrees, Minutes and Seconds39° 40' 37.74" N, 78° 13' 35.82" W
Driving DirectionsGoogle Maps
Area Code(s)301, 240
Closest Postal AddressAt or near Western Maryland Rail Trail, Hancock MD 21750, US
Alternative Maps Google Maps, MapQuest, Bing Maps, Yahoo Maps, MSR Maps, OpenCycleMap, MyTopo Maps, OpenStreetMap

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