See solar calendars in Petrified National Forest

Submitted by coldrum on Saturday, 20 June 2009 Page Views: 3073

Solar calendars have been discovered throughout the Southwest marking the summer and winter solstice and the equinoxes. In Arizona, nowhere is the evidence more visual then at The Petrified National Forest outside of Holbrook, where solar calendars were used by ancient civilizations to plan their seasons.

Around the world, cultures have been fascinated with the passage of the seasons and movements of the sun and moon, creating such places as Stonehenge in the United Kingdom, Carnac Stones of France, and Uxmal in the Yucatan. For several thousand years, the prehistoric people of the Southwest have made their own versions of these ancient calendars. Solar calendars are petroglyphs which interact with sunlight and shadow as the sun moves across the sky to mark the passage of the seasons.

Starting today and continuing daily from 8:30 a.m. to 9:30 a.m. through June 28, to U.S. Forest Rangers at Puerco Pueblo in the Petrified National Forest will help visitors watch an ancient solar calendar - which peaks about 9 a.m. each morning - as part of the park's Summer Solstice Celebration.

Puerco Pueblo is located in the middle of the park on the main road, 11 miles from the north entrance. A short paved trail leads through Puerco Pueblo to a boulder featuring a small spiral petroglyph that marks the summer solstice. During the sun's morning trek, a shaft of light is projected onto the boulder and travels down the side to touch the center of the spiral.

While visiting the forest, you will find that not all plants at Petrified Forest National Park are fossils. Living plants are critical components within the grassland ecosystem found throughout the park. Plants capture particulate dust in the air, filter gaseous pollutants, convert carbon dioxide to oxygen, provide habitat for animals and supply raw materials for humans.

Plants make use of soil pockets, even those collected within petrified wood pieces. Plants of arid climates have adaptations which enable them to survive the extremes of temperature and precipitation.

These adaptations can be grouped in two basic categories: drought escapers and drought resistors.

Drought escapers are plants which take advantage of favorable growing conditions when they exist, but go dormant when those conditions disappear. They are usually annuals, growing only when enough water is available. Seeds produced under good conditions can lie dormant for years if conditions are not favorable for germination. Most grasses and wildflowers are drought escapers.

Drought resistors are typically perennials. They have mechanisms for reducing the damage a drought can cause. For example, some will drop their leaves if water is unavailable. Many have small, hairy leaves which reduce exposure to air currents and solar radiation and thereby limit the amount of water lost to evaporation. Cacti, yuccas and mosses are examples of drought resistors. Yuccas have extensive taproots which can reach water beyond the ability of other plants. Mosses can tolerate complete dehydration. When rains return after extensive dry periods, mosses green up immediately.

Enjoy this unique Arizona event, highlighting Arizona as a natural playground.

eastvalleytribune.

Contributor Bio for coldrum: Based in Milkyway, contributing since 2002. Favourite site: Avebury.

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