page_title: Cinder Cone and the Fantastic Lava Beds
section_title: Description and geology
hierarchical_section_title: Cinder Cone and the Fantastic Lava Beds / Description and geology
context_page_description: Cinder Cone is a cinder cone volcano in Lassen Volcanic National Park within the United States. It is located about 10 miles northeast of Lassen Peak and provides an excellent view of Brokeoff Mountain, Lassen Peak, and Chaos Crags.
  The cone was built to a height of 750 feet above the surrounding area and spread ash over 30 square miles. Then, like many cinder cones, it was snuffed out when several basalt lava flows erupted from its base. These flows, called the Fantastic Lava Beds, spread northeast and southwest, and dammed creeks, first creating Snag Lake on the south and then Butte Lake to the north. Butte Lake is fed by water from Snag Lake seeping through the lava beds. Nobles Emigrant Trail goes around Snag Lake and follows the edge of the lava beds.
  Its age has been controversial since the 1870s, when many people thought it was only a few decades old. Later, the cone and associated lava flows were thought to have formed about 1700 or during a 300-year- long series of eruptions ending in 1851. Recent studies by U.S.
context_section_description: Cinder Cone is a 700-foot (210 m)-high volcanic cone of loose scoria. The youngest mafic volcano in the Lassen volcanic center, it is surrounded by unvegetated block lava and has concentric craters at its summit, which have diameters of 1,050 feet (320 m) and 590 feet (180 m). Cinder Cone comprises five basaltic andesite and andesite lava flows, and it also has two cinder cone volcanoes, with two scoria cones, the first of which was mostly destroyed by lava flows from its base. Cinder cone volcanoes are typically monogenetic, meaning that they only undergo one eruptive period before ceasing activity forever. These eruptions often consist of the ejection of tephra, though they may also generate lava flows, which often originate from vents near the base rather than the summit of the volcanic edifice.
  The summit of Cinder Cone has a crater with a double rim (photo), probably created by two different phases of one eruptive period. The cone also has a widespread ash deposit identifiable for 8 to 10 miles (13 to 16 km) from the cone. Blocks of red, cemented scoria within the Painted Dunes lava flows (photo) are pieces of this earlier cone, which were carried away by the flowing lava.
  When Cinder Cone formed, the magma feeding the eruption changed composition, shifting from basaltic andesite to andesite before returning to basaltic andesite with increased titanium content. While basaltic andesites are volcanic rocks containing 53 to 57% silica, andesites are those containing 57 to 63% silica. The lava flows and scorias at the volcano closely resemble each other despite distinct chemical compositions, forming dark, fine-grained rocks, with a few visible crystals of the minerals olivine, plagioclase, and quartz.
  The early group of volcanic deposits at Cinder Cone, which have relatively little titanium, include older scoria cone, the Old Bench flow, the two Painted Dunes flows, and the lower part of the widespread ash layer. The second group, erupted later and comparatively rich in titanium, consists of the large, younger scoria cone, the upper part of the ash layer, and the two Fantastic Lava Beds flows. The second Fantastic Lava Beds flow that all scientists but Diller thought had been erupted in 1851. At the Old Bench and Painted Dunes lava flows, the volcanic ash is brightly oxidized because it interacted with the lava flows when they were still hot. It shares its compositional group with the Fantastic Lava Beds flows, which represent the last flows erupted at Cinder Cone. Ultimately, the eruptive sequence at Cinder Cone took place over the course of several months.
  An unusual characteristic of the Fantastic Lava Beds is the presence of anomalous quartz crystal xenocrysts (foreign bodies in igneous rock). Geologists think that they were picked up from wall rocks by the lava as it moved toward the surface.
caption: Cinder Cone is in Lassen Volcanic National Park.
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