The  Petroglyph National Monument

Stone Images From The Pueblo Indians

Albuquerque, NM

April 27, 2003

One of the fun things to do when in the Albuquerque area is to wander out toward the west, and tour the Petroglyph National Monument, where there is a world of prehistoric history just laying around to be observed. . Having driven out to the the Ranger Station, we picked up a copy of the Boca Negra Canyon Trail Guide and started out.  Right away we found out that the Petroglyph National Monument preserves one of the largest Petroglyph sites in North America.  The Monument was established in 1990, to protect and interpret petroglyphs and archaeological sites on Albuquerque's West Mesa. It is managed jointly by several organizations including Albuquerque, and the National Park Service. The West Mesa escarpment is a 17-mile long ridge of basalt boulders, created by volcanic eruptions that occurred about 130,000 years ago. The first two volcanic events were extensive flows of fairly liquid lava, which flowed down old arroyo courses that can now be seen as peninsulas on the escarpment.  Similarly, lava flowed around hills and higher ground to create the natural embayment on the escarpment (an effect called "reverse topography"). Subsequent eruptions of increasingly thicker lava covered smaller areas and the last events created the volcanic cones themselves. Once we got to the top of the Mesa point Trail we saw the now dormant volcanic cones. In the millennia following the eruptions, the Rio Grande eroded the basalt caprock of the escarpment.  The flows ranged from just 5 feet thick in places to over 50 feet thick in other places. The caprock can be seen across from the Canyon trail.  Huge pieces of the basalt caprock were undermined by the mighty river's meandering and were left strewn all along the escarpment face. Millions of these boulders have been left exposed to the elements.  This exposure caused what is called "desert varnish" which is a pronounced oxidation of metals such as manganese and iron within the basalt.  This dark "desert varnish", or patina is extremely thin and chipping or pecking exposes the lighter color of the rock underneath.  It is the secret to the high contrast images which are found on the rocks. Although they last seemingly forever, it is not true.  From the day they were pecked out, the elements have started their inevitable tarnish, slowly, yet ever so slowly, turning the once brilliant images back into the dark surface from which they were created. Surveys suggest that there are at  least 20,000 petroglyphs along the volcanic escarpment.  Petroglyphs are a valuable record of cultural expression and have deep spiritual significance to modern Indian groups. Interest in such images run in two distinct areas.  The first is in attempting to find out just how old the drawings are, and the other is in trying to identify the specific meaning of each image which includes by its nature, the identity of the people who made them. In regards to the date when the  petroglyphs were carved, we learned that there are many ways of determining when the drawing were created.  While walking the trail, I noticed that the prehistoric petroglyphs typically face south or southeast.  It is believed that many of the images were made during the winter when these south facing boulders would have been warmer and clear of snow accumulations. We also found out that  most petroglyphs images in the park have been dated by "relative dating" techniques.  That is, they are compared to stylistically similar, datable pottery designs and other dated artifacts such as prehistoric Puebloan murals. These murals had colorful painted stories on the plaster walls of kivas (subterranean ceremonial rooms).   Most of the petroglyphs in this area are believed to be of the "Rio Grande style" which was from 1300 AD to 1680 AD.  During that time, the Rio Grande Valley was populated by the Pueblo Indians.  That area extended to the escarpments at the Petroglyph National Monument. Yet another method is to use the very cause that allowed the images to be created and  will someday cover them up again. The amount of  "desert varnish" that has reappeared since the image was created can be estimated. As this occurs at a predictable rate, a general idea of the date came be established. As far as who made the drawings and what they mean, we learned that the identification of the various petroglyphs is often based on contemporary ethnographic interpretations. That is, they are based on interpretations by today's Pueblo people. It is not known for certain what all the images represent.  Different Pueblos have differing opinions on meanings and any one image may have complex or multiple meanings based on its context.  Some images have direct meaning to modern tribes while the meaning of others has been lost over the centuries.  Whatever their interpretation petroglyphs preserve the beliefs of their makers and are part of our heritage and the heritage of the Indian peoples who still live in the area. The walk was moderately strenuous and about a half a mile in length.  Along the way there were plenty of opportunities to find the desert creatures that inhabit the area.  The best we did was some very interesting lizards and a few snake trails.  All in all, a great way to spend the afternoon wandering in the sun and fun of central New Mexico.

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