- Miniature Volcanoes
On the slope below you is a small spatter cone. Spatter cones, or hornitos (“little ovens” in Spanish), form when lava is forced up through an opening in the cooled surface of a lava flow. They are “rootless,” fed by the underlying flow rather than a deep magma conduit. Can you picture fluid fragments of liquid spurting upward, flattening, congealing, and mounding around the opening? Can you imagine approaching an erupting spatter cone? Unique artifacts found nearby – corn casts in lava rock – suggest people did. Experiments conducted in Hawaii demonstrated that “corn rocks,” like the one on display in the visitor center, can form when ears of corn are covered by fluid blobs of spatter. It appears people intentionally ventured close to an active hornito, maybe this one, to leave corn – perhaps as an offering. More than 50 rocks with corn casts have been found in homesites attributed to the local Sinagua cultural tradition. - mining
- O'Leary Peak
Look for a dome volcano (O’Leary Peak) on the horizon in front of you. Dome volcanoes tend to have steep sides and rounded shape. - Obsidian Projectile Points
Description: Obsidian projectile points. Dimensions: Left-2.3 cm (L), 1.0 cm (W), 0.3 cm (Th), Middle-2.7 cm (L), 1.3 cm (W), 0.4 cm (Th), Right-1.78 cm (L), 1.22 cm (W), 0.4 cm (Th). Collection: On display at the Sunset Crater Volcano National Monument Visitor Center (catalog card 1, catalog card 2, catalog card 3). - One Volcano Amid Many
At nearly 1,000 years young, Sunset Crater volcano is a geological infant, the latest development in a series of eruptions that have taken place here over the past 6 million years. It is only a small part of the impressive San Francisco Volcanic field of northern Arizona. From this point, three different types of volcanoes are visible. What makes a volcano tall or short, steep or gentle, or an eruption more or less violent? Mostly the magma’s stickiness or viscosity, which is determined by its chemical composition and gas content. Cinder cones, like Sunset crater and most of the 6000 or so volcanoes in this field, tend to be cone shaped with sides not steeper than 33 degrees. A cinder cone is literally a pile of loose fragments. It is easily eroded and will change shape, becoming less steep as it ages. - ORV
- Our Dynamic Earth
Alpine slopes, forests, and grassy parks disguise the fiery, molten, and often explosive history of this region’s landscape. But here, amidst the Bonito Lava Flow and Sunset Crater’s cinder fields, the land’s volcanic origin is revealed in stunning clarity. As you walk the trail, use this guide to explore the powerful forces – rapid and violent, slow and patient – that continually shape our planet. These forces all affect our lives and provide for life in ways we may not realize. - Paricutin
Volcanic eruptions may seem destructive but they are among the beneficial forces of a living planet: forces that build mountains, create oceans, and provide for live. Only when our planet has finished cooling will there be no volcanoes. Then, Earth will be a dead planet much like Mars. The eruption of Parícutin in Mexico, 1943, is considered the modern day equivalent of the Sunset eruption. - Penstemon
Along the perimeter of the flow, a unique microhabitat for plants exists. In places, water collects on the surface of the flow and is then channeled through fractures to the edge where it locally benefits plants. White-barked aspen trees grow around the perimeter of the flow and along fracture systems. In area of deep cinder, like the dunes in the distance to your left, specialized plants have evolved. The Sunset Crater penstemon evolved new traits which allow it to live on cinder soils but also make this endemic plant dependent on this habitat. It cannot survive elsewhere. - Power to Symbolize
- Preparing to Test Equipment, 1964
Description: In 1964, the first field tests using NASA space suits took place on the Bonito Lava Flow and the deep bordering cinder. Here, the crew poses alongside the equipment truck, with the Bonito Lava Flow behind them. Collection: Sunset Crater Volcano National Monument. - Ropes and Clinkers
You are now on the southern edge of the Bonito Lava Flow. Magma, periodically relieved of gas pressure, squeezed out of the base of the cone as glowing liquid lava, creating a structurally complex flow covering 2 sq miles (5 sq km). Lava flows tend to form either jagged blocks, known as aa (ah-ah), or a smooth, ropey surface of pahoehoe (pa-hoy-hoy). Flows usually start as pahoehoe, thin and runny. As the lava cools and becomes more thick and pasty, it can change into an aa flow. The Bonito Flow is mostly aa lava. When aa is forming, cooled, hardened blocks - sometimes called clinkers - are rafted along the surface of moving lava, making clinking noises as they tumble into each other. Although its structure is complicated, the flow’s composition is uniform throughout. The lava and cinders around you, whether black or red, ropey or jagged, are basalt. - San Francisco Peaks
Composite or stratovolcanoes have sharp peaks or less steep sides. Mount St. Helens, Mount Fuji, and the San Francisco Peaks, seen here in the distance, are examples of this classic volcano type. - Squash Blossom Necklace
Description: Navajo silver and turquoise squash blossom necklace from the Museum of Northern Arizona gift shop. The necklace dates to the 1930s or 1940s, and has three blue turquoise stones in the hand-stamped naja, or the crescent pendant portion of the necklace and 20 silver squash blossoms evenly distributed on each length of the necklace (10 on each side). Dimensions: 16 in (L), Pendant-2.5 in (W), 2.25 in(L). Collection: On display at the Sunset Crater Volcano National Monument Visitor Center (catalog card). - Squash Blossom Necklace, Close-up
Description: Navajo silver and turquoise squash blossom necklace from the Museum of Northern Arizona gift shop. The necklace dates to the 1930s or 1940s, and has three blue turquoise stones in the hand-stamped naja, or the crescent pendant portion of the necklace and 20 silver squash blossoms evenly distributed on each length of the necklace (10 on each side). Dimensions: 16 in (L), Pendant-2.5 in (W), 2.25 in(L). Collection: On display at the Sunset Crater Volcano National Monument Visitor Center (catalog card).