500 million years ago this desert was a sea…
Warm, shallow, and teeming with life. For four hundred million years, marine animals and plants thrived in the sun-lit depth of this watery world.
Valley of Fire is a geologic park built of rocks of many colors: white, gray, brown, purple, red. No matter what their color, nearly all of them are forms of the same type of rock: sedimentary. They tell a story of ancient seas and beaches, of times when heat from deep in the earth changed the mantle at the surface.
Some of these building blocks are 300 million years old; others are much younger. All of them were created by geologic processes that have been operating on this earth since the beginning of time. Each process creates a different kind of rock, and all rocks are continually changing because of these slow but irresistible forces. In Valley of Fire, there are mostly sedimentary rocks, laid down as sand, mud, silt or lime which slowly turned to stone.
The Valley Today and Tomorrow
The geologic forces acting upon our earth are slow but irresistible. We may only see small changes, such as the crumbling of a cliff face, but all the time, mostly unnoticed, there are massive pressures that build mountains, followed by erosion that wear them back down.
The creation of the Valley of Fire took hundreds of millions of years, and the result is one of the most geologically interesting and scenic areas in Nevada. This magnificent area is very sensitive and it is the responsibility of every visitor to take care to preserve this desert wonderland for future generations.
Sedimentary rocks result from erosion and gravity acting on igneous rocks, which are made from magma: the liquid rock found deep within the earth. Wind, heat and cold combine with water and ice to wear these foundation rocks down into minute grains of sand, and then move them around.
Eventually, the sand is compressed and cemented together into new rocks. Often plant and animal remains are deposited in the mud, sand, and gravel and are preserved as these soft layers turn to rock. These deposits, or sediments, cemented together by minerals, are called sedimentary rock.
Beehives
The Beehives are sandstone formations that not only demonstrate the unique design that can be created by nature, but are also an excellent representation of geologic cross bedding. Those are the grooved lines going in different directions. The layers, or beds, represent different layers of silt that are deposited at different times.
The beds indicate the angle of the wind or water was moving at the time the material was deposited. Cross bedding is very common in sand dunes, beach deposits and river sediments.
A short path winds through rocky dunes with hills of the Muddy Mountains visible in the distance.
Petrified Logs
Millions of years ago, this tree likely grew with others of its kind in a forest several miles from here. Later, flood waters carried the fallen log to this area where it was buried beneath thousands of feet of silt, sand and sea deposits. Here it slowly changed to stone. The trees here are ancient pines that grew near here during the great Age of Reptiles, approximately 150 million years ago.
Petrified fossils form when minerals replace the structure of an organism. This process, called permineralization, occurs when groundwater solutions saturate the remains of buried plants or animals. As the water evaporates, the minerals remain, eventually filling in the spaces left as the organism slowly decays. Over millions of years, the actual wood in these petrified logs was replaced by silica and eventually became a solid mass of rock.
Atlatl Rock
An atlatl is a throwing stick or a dart thrower used by ancient tribes to give more force to their darts or spears. It was usually a wooden stick about two feet long with a handhold on one end and a hook on the other. The tail end of the dart was set against the hook, allowing the hunter to hold onto both atlatl and dart when throwing.
These petroglyphs were made by ancient tribes.
Petroglyphs
These petroglyphs have existed for over 4,000 years. Ancient drawings reflect the past and the lifestyles of indigenous cultures. Although we don’t exactly know the meaning of the images, this art reflects the thoughts of humans who have come here before us.
Cryptobiotic Soil
You will find patches of black crust on the soil throughout the desert. This is known as cryptobiotic soil and it is very sensitive and important to the ecosystem. The soil is a mixture of algae, lichens, mosses and cyanobacteria. It provides nutrients for plants and seeds and improves the soil typography and moister absorption. The crust is only a few millimetres thick, so do not step on it as it can take between 7-250 years to rebuild.
Rainbow of the Desert
The color of the sandstone is a result of the minerals in the rock
Red – Iron oxide
Yellow/tan – silica
Purplish – manganese
White/cream – purer sandstone that has been stripped of minerals such as iron oxide
Desert Bighorn Sheep
Bighorn sheep can be found in the desert ranges of the Southwest, but numbers are small and distribution is spotty. This animal prefers rocky canyons and hillsides, though it is occasionally seen on the flats in winter, moving from one desert range to another. This large desert animal can be easily identified by its curled horns that are worn by the males, or “rams”. The females, or “ewes”, have much narrower horns, rarely exceeding fifteen inches in curl.
Bighorn sheep do not require drinking water in the winter while green vegetation is available. However, in the summer months bighorn visit watering holes at least every three days.
