Hiking Piedras Marcadas Canyon
Piedras Macrodas means Marked Rock
January 2, 2010
Geologic History

150,000 years ago, the Albuquerque area was rife with volcanic activity. It was at this time that the West Mesa, a 17-mile long land table emerged from hardening layers of continuously flowing lava. Over time, the softer sediment of the volcanic mesa's eastern edge began to erode, leaving behind the 17-mile long escarpment that is Petroglyph National Monument. As stated above, an 'escarpment' is a long, precipitous, cliff like ridge of land or rock, commonly formed by faulting or fracturing of the earth's crust.

Along the escarpment are rocks and boulders made of basalt, formed by the hardening lava flows and volcanic spew. Basalt erodes slower than the sediment beneath it eventually releasing the rocks and boulders to tumble down the canyon walls, no longer supported by their 'softer' sandstone base.

Over time, a 'desert varnish' has darkened the face of most of these basalt rocks, forming endless blank canvasses from which the Ancestral Pueblos created Petroglyphs. A petroglyph is a picture, symbol, or other piece of art work pecked, carved or incised into natural rock surfaces.

The dark desert varnish on the face of the basalt rocks was caused by the oxidation of minerals such as manganese and iron. By chipping away at this dark desert varnish, the light colored underside of the rock was revealed, enabling ancient peoples to communicate with each other through pictures and symbols.

Petroglyphs

There are 20,000 Petroglyphs in the Petroglyphs National Monument and 1/3 of these are in Piedras Marcadas Canyon. 90 to 95% of these are the Rio Grande type dated from 1530 to 1680 AD.

Why were the Petroglyphs made?

There were many reasons for creating the Petroglyphs, most of which are not well understood by non-Indians. Petroglyphs are more than just "rock art," picture writing, or an imitation of the natural world. They should not be confused with hieroglyphics, which are symbols used to represent words, nor thought of as ancient Indian graffiti. Petroglyphs are powerful cultural symbols that reflect the complex societies and religions of the surrounding tribes. The context of each image is extremely important and integral to its meaning. Note each petroglyph's orientation to the horizon and surrounding images, as well as the landscape in which it sits. Today's native people have stated that the placement of each petroglyph image was not a casual or random decision. Some Petroglyphs have meanings that are only known to the individuals who made them. Others represent tribal, clan, kiva or society markers. Some are religious entities and others show who came to the area and where they went. Some Petroglyphs still have contemporary meaning, while the meaning of others is no longer known, but are respected for belonging to "those who came before".


Pictures

[Return]