A February 2003 trip
to Petrified Forest National Park by Taylor252
Quote: When I was a small child, my mother showed me a piece of petrified wood she had. Ever since then, I have wanted to see the Petrified Forest for myself!
Attraction | "Petrified Forest--The Logs of Rock"
Starting from the south as we did, the first opportunity to see petrified logs is a place called "Giant Logs" Guess what you see here? At this site will be the Rainbow Forest Museum which has a dinosaur on display as well as other displays about the park. There is also a bathroom at the facility! However, the star of the museum in out back. You are given a self guided tour brochure and shown the paved trail. It is about .4 miles long. Although the trail is not handicapped accessible, it is a fairly easy walk with a few stairs to climb. .The self guided tour suggested we spend at least 20 minutes at this site. So we did! The trail winds through some of the biggest trees in the park, including the biggest, "Old Faithful" whose diameter at the thickest point is 9 ft. Most of the logs at this stop and throughout the park are broken into pieces. Because the pieces all fit together and even the lines of petrification match, we know these trees were solid when they were transformed. The breakage is probably due to stress on the log as the uplift of the Colorado plateau happened. Petrified logs are made out of quartz which will fracture and break fairly easily when in long crystals. We talk about quartz like it is one substance, however, the silica which created the petrified logs is clear quartz only in its purest form. Jasper, agate, and chalcedony are also forms of quartz.
When you visit the petrified forest, you'll notice that clear quartz is very rare. Yellow, red, and brown colorings are due to iron oxides. Black is from carbon. Rarely blues and purples can be found as iron oxides and carbon combine in unusual proportions.
The next major stop for log viewing is the "Long Logs Trail". It is 1/2 mile and meanders through the longest logs in the park -- the longest being close to 150 feet. The next area will be "Crystal Forest Trail" about 3/4 a mile. At one time, several of the hollows in these logs contained amethyst crystals. "Jasper Forest" is another place you can overlook petrified logs strewn about. These places comprise the biggest concentrations of logs in the park. You will see logs individually at times, but don't expect to see them everywhere. They are mostly in the southern part of the park. Other areas in the park will be devoted to archeology or geological formations.
Member Rating 5 out of 5 on August 30, 2003
Petrified Forest National Park
Petrified Forest National Park, Arizona 86028
Attraction | "History and Archeology in the Park"
At its height, Puerco had close to 100 rooms which were probably each one for a family. There were several communal kivas where the men met to talk or work. But unlike other village sites, there wasn't very much left behind when these folks moved on. That told scientists that it was a planned move. However, in one room an altar slab was found. It is very much like the ones used by the Hopi to this day which has led to the speculation that this ancient tribe may have contributed to the rise of the Hopi tribe.
The people of Puerco were contemporaries of the Anasazi to the north, the Sinagua and Hohokam to the west and the Mogollon to the south. However, this is a relatively late pueblo. Mesa Verde was abandoned while this site was still active. There was a group here is the 1100's A.D. and then again in the 1300s. The fact that it had been inhabited and abandoned in the past seemed to me support for the idea that this site was finally abandoned due to water and climate changes for the worse. NOTE: It is here that you will find the spiral solar calendar mentioned in the Petroglyphs entry.
One other old human habitation is worth a look. It is called the Agate House, because it is build completely with petrified wood. It was built somewhere between 1050 and 1300 A.D. and completely reconstructed in 1934. There was very little trash indicating it wasn't inhabited very long. My speculation was it might have been a "honeymoon" type retreat for newlyweds. But I assure you, that is my own speculation and is based on the dating.
NOTE: There are now over 600 identified sites of human habitation in the Park, some dating to pre-ceramic ages -- around 200 A.D. Most of these remain unknown to the public for their safety and preservation.
Petrified Forest National Park, Arizona
Attraction | "Painted Desert-The Geology of Petrified Forest"
As new as the Chinle Formation is, there is an even younger layer that can be seen in places. After the Chinle sediments were put down, a layer of lava from long gone, but formerly local volcanoes, created another layer called the Bidahochi Formation. It is aprox. 12 million years old and can be seen at Pilot Rock in the Painted Desert and a few other places. It is basically basalt.
You will occasionally see a butte in the park. How are they formed? It was a question that interested me. A butte is basically harder rock than that which is around it. The softer stone erodes away leaving the spire. Also some of them are old lava tubes from volcanoes. (This is essentially how the petrified logs were exposed again after such a long period of time. They are very hard rock surrounded by essentially sandstone which is very soft!) The rubble deposits of the actual volcanic cone have completely eroded away leaving the lava filled tube standing by itself. I didn't know this, but there are over 200 existing volcanic cones in northern Arizona and one, Sunset Crater, erupted only 1000 years ago. The area is considered to still be active.
Petrified Forest National Park, Arizona
As we entered the park, we picked up a self guided tour, a map, and visited the souvenir shops to check the prices and get a coke. The park is 93,533 acres and contains unique archeological, paleontological, and geological formations. There is a lot to see and it can take a while even if the park is as empty as it was on our visit. (we saw another car about every 5 minutes). We were told that in the summer, cars can be lined up and moving less than 5 mph. The total length of the road is approx. 28 miles. If you do the math, in summer, time spent in the car . . . well . . . we recommend going in winter if you can! Otherwise, plan to arrive very early before the majority of folks get there. Also, the park averages a little over a mile high in elevation. That can bother some people so check it out.
The trees that litter the ground now as petrified wood originally grew in the Triassic Period (200-250 million years ago) and were all conifers (i.e. evergreens). They grew in a tropical rain forest at the time. For whatever reason, the trees fell down and were washed out on to the flood plain. At the same time volcanoes in the area were putting a lot of ash into the air. The ash mixed with the mud sediments covering the trees. Then, as the rain washed the silica out of the ash, it seeped down into the logs, slowly replacing the organic material with quartz or agate. And we end up with petrified wood! There are actually different kinds of petrified wood distinguished by three conditions. First there are three species of extinct trees that make up the logs. Second, some of the silica was colored by other minerals to get the rainbow of colors you find in the rocks. And third, sometimes the petrification process was so good that cellular structure was duplicated and/or sometimes bark can be distinguished. All of these things determine the value of a piece of petrified wood. So, if you want to buy enough to make a table, do your homework and plan ahead. It will be very heavy!
Attraction | "Petroglyphs!"
As you read about petroglyphs you discover that scientists really aren't sure why they were made or for that matter how old they are. We can date the rock they're on or perhaps date the ruins they may be close to, but that doesn't really tell how old the drawings are. Nor do they completely understand what they mean. We know they took time to make, so the chances of these being random doodlings seems less likely, but they could be an ancient expression of art, or mark an animal trail, or a way to ask for blessings from the gods for a particular event. There is one exception. At least one of the glyphs is a solar calendar. At solstice and equinox, a shaft of light will creep across the rock face and move precisely through the center of a spiral drawing.
Petroglyphs are made possible by a dark layer called "desert varnish" that sometimes covers the rocks. This varnish is a combination of iron or manganese with bacteria and it grows harder and blacker with time. This dark "varnish" provides a contrast layer to the light colored rock below and allows the petroglyph to be carved into the rock. If you look real close, you can see individual chip marks still in the glyphs. This was not like drawing; it was more like sculpting with a hammer and pick. Perhaps that's why stick figures are more common.
For those that are interested, I will add that archeologists have categorized petroglyphs into six categories. They are anthropomorphs, geometrics, kachinas, hands/tracks, zoomorphs, and indeterminate. Anthropomorphs have something to do with the pictures of people. Geometrics are boxes, circles, spirals etc. Kachinas are usually heads/masks with features. Hands/tracks are simply a hand print or the representation of the tracks of some animal. Zoomorphs are pictures of animals. I counted about seven different animals, but I'm sure there are more. Indeterminate is a category for anything that just can't be put in any other category.
After Newspaper Rock, there is one other place where the petroglyphs can be seen. That is at the Puerco Pueblo ruins. You can get closer to them at this location and there is a bathroom available at this location.
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