Inscription Preservation

National Park Service conservators monitor inscriptions yearly and preservation techniques are implemented on the most threatened.

NPS photo

The inscriptions and petroglyphs at El Morro are a part of our heritage, and although they are very old, they will not be here forever. Sand grains are washed away, rocks crumble and fall, and lichens and clay deposits cover the historic carvings.

You may wonder what is being done to preserve the inscriptions. The National Park Service hopes to delay their deterioration for as long as possible by monitoring and treating threatened inscriptions. When the loss of an inscription is imminent, conservators may:

• use grout to fill holes, keeping water out.
  
  
• consolidate loose rock around eroding inscriptions with ethyl silicate and epoxide.
  
  
• secure inscription panels with drilled pins.
  
  
• treat with calcium hypochloride (swimming pool bleach) to stop lichen growth over inscriptions.

 

NPS photo

As early as the 1920s, park managers have been concerned with protecting inscriptions from the elements of nature. Early efforts included covering the carvings with parafin, chiseling grooves to reroute water flows (image right) and darkening and deepening inscriptions with hard pencils to offset the erosion that was occurring.

These first, well-intended though intrusive attempts to preserve the inscriptions ended in the 1930s, though even today you will see remnants of the darkening technique in some of the Spanish carvings.