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Engineering on the Trail

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Photo: The Potomac Canal at Great Falls Park, NPS by A. Toure

Article and photos by FMN Stephen Tzikas, except as noted

There are a lot of “roadside engineering” ruins found along roads and trails.  I like to visit them when I travel to nearby states. Typically these engineering ruins include iron furnaces, canals, and grist mills, but may include other interesting relics of industrial archaeology. We have such places in Fairfax County.

The ruins of Matildaville

At Great Falls Park, the geology of the area gave rise to engineering associations. River processes involve many engineering principles related to fluid mechanics. Rivers, too, offer opportunities for the application of geology for engineering works such as transport and power generation. Here in Great Falls Park, a complex of ruins are associated with a canal.  The ruins of Matildaville are located along one of the trails. It was a town associated with a canal built next to the Potomac River.  The ruins date from 1790, when the town was planned as an industrial community which would support canal operations. The town started as a staging and headquarters area for the construction of a canal. The town included a forge, a gristmill, a store, storage buildings, the superintendent’s house, a market, a sawmill, an ice house, worker barracks, boarding houses, a few smaller homes, and an inn.  Construction of the canal took 17 years, becoming operational in 1802. However, the Patowmack Company succumbed in 1828, turning over its assets and liabilities to the newly formed Chesapeake and Ohio Canal Company, whose canal ruins are also in the nearby area.  Alas the town did not survive the closing of the canal in 1830.  Eventually all canals were made obsolete by the railroad.

A Potomac Canal Lock at Great Falls Park

The stone ruins of an upstream portion of the Potomac Canal at Great Falls Park usually does not have water flowing in it, but on rare occasions it does.  Canal ruins that are usually seen, such at Great Falls Park, are of locks.  A boat going down stream entered a lock at its upper end.  At the lower end a gate kept the water in.  The upper gate was then closed.  Values in the lower gate were opened to lower the water level to the next lock downstream.  The lower gate was opened and the boat proceeded to the next lock.  For boats going upstream, the procedure was reversed.  If a location had a mountain lake such as the Morris Canal in New Jersey, these engineering marvels could even literally cross over a mountain!

 

The Annual Virginia Geological Research Symposium

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Feature photo:  At the 2019 Virginia Geological Field Conference, our excursion group investigated the landslide damage of Hurricane Camille in Nelson County. After 50 years this mountainside is still stripped to its bedrock from the floods and landslides caused by the hurricane.

Article and photo by FMN Stephen Tzikas

The annual Virginia Geological Research Symposium is an event I enjoy attending. It is typically held in April and is approved for the FMN Better Impact continuing education requirement. It is presented at a professional level and is a conference from which one can acquire valuable knowledge if working in the associated engineering and science fields. Moreover, because it is Virginia centric and geology related, it’s a great learning venture for Virginia master naturalists.

The last couple of years the symposium was held virtually, but it normally meets in Charlottesville. It is free and hosted by Virginia Energy, Geology and Mineral Resources. This organization serves as Virginia’s geological survey. The last symposium was held on April 21, 2022. At this symposium, the U.S. Geological Survey gave a couple presentations related to the 2011 Mineral, Virginia 5.7 magnitude earthquake felt over a wide area including Fairfax County (something most of us will remember). The quake was further discussed in the context of the more recent 2020 Sparta, North Carolina 5.1 magnitude earthquake. Other presentations given by the U.S. Geological Survey included Earth MRI geophysical datasets along the fall-line in SE Virginia and NE North Carolina, and the origin of Carolina Bays in the Coastal Plain of Virginia.

The College of William and Mary had several presenters too. Topics included:

  • Age and origin of the Albemarle-Nelson mafic-ultramafic complex in the eastern Blue Ridge.
  • Structural geology and geochronology of the Shores Melange in the Piedmont.
  • Geology of the Schuyler 7.5-minute quadrangle in central Virginia and understanding Iapetan rifting, sedimentation, and magmatism.
  • Petrology, structure, and geochronology of the Oakville metavolcanic sequence and the implications for the provenance of the Smith River Allochthon.

Of particular interest to me was the landslide hazard mapping in western Albemarle and Nelson Counties by Virginia Energy. I once attended a geologic field trip to Nelson County, the location hit hard by Hurricane Camille in 1969 through the devastating flooding and landslides caused by the hurricane. Another interesting topic was on geologic storage potential in Virginia, also by Virginia Energy.

James Madison University and Radford University students made presentations too.

It is worth exploring the Virginia Energy website at https://www.energy.virginia.gov/. The website features such links as “Ask a Geologist” and information on the geology and mineral resources of Virginia at https://www.energy.virginia.gov/geology/geologymineralresources.shtml.

This symposium is a wonderful resource among many available for geology enthusiasts in Fairfax County. Others include are:

  • The Northern Virginia Mineral Club: https://www.novamineralclub.org/
  • The Annual Gem, Mineral and Fossil Show at George Mason University
  • NVCC 1-day 1-credit excursions (Field Studies in Geology under GOL-135)
  • The Virginia Geological Field Conference (also with counterparts in PA, NJ, and NY)https://vgfc.blogs.wm.edu/