Mount Shasta

From The Book of THoTH (Leaves of Wisdom)

Mount Shasta, a 14,162-foot (4,322 m) stratovolcano, is the second-highest peak in the Cascade Range and the seventh-highest peak in California.[1] The mountain stands 10,000 feet (3,000 m) above the surrounding area and has an estimated volume of 108 mile³ (450 km³). Variant spellings of the name Shasta were first applied to the Oregon volcano now named Mount McLoughlin in the 1820s, but by the 1840s the name had been transposed to the current Mount Shasta.

The mountain consists of four cones buried atop one another. Shastina 12,300 ft (3,749 m) is the most obvious cone and forms a lesser summit. It has a fully intact summit crater which shows that Shastina postdates the last ice age. The rest of Shasta's surface is relatively free of glacial erosion except, paradoxically, for its south side where Sargents Ridge runs parallel to the U-shaped Avalanche Gulch (the largest glacial valley on the volcano, although it does not presently have a glacier in it). There are five named, yet small, glaciers clustered on the mountain's north side.

There are many buried glacial scars on the mountain that were originally excavated in glacial periods ("ice ages") of the present Wisconsinian glaciation. Most have since been filled-in with andesite lava, pyroclastic flows, and talus from lava domes.

1 Geology
2 Volcanic hazards
3 Religion
4 Cultural references
5 References
6 See also
7 External links

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Geology

Shasta Valley

About 593,000 years ago andesitic lavas erupted in what is now Mount Shasta's western flank near McBride Spring. Over time an ancestral Shasta stratovolcano was built to an unknown height but sometime between 300,000 to 360,000 the entire north side of the volcano collapsed, creating an enormous landslide, 6.5 mile³ (27 km³) in volume. The slide flowed northwestward into Shasta Valley where the Shasta River now cuts through the 28 mile (45 km) long flow.

The remains of the oldest of Shasta's four cones is now exposed at Seageants Ridge on the south side of the mountain. Lavas from the Sargeants Ridge vent cover the Everitt Hill shield at Shasta's southern foot. The last lavas to erupt from the vent were hornblende-pyroxene andesites with a hornblende dacite dome at its summit. Glacial erosion has since modified its shape.

The next cone to form is presently exposed south of Shasta's current summit and is called Misery Hill. It was formed 15,000 to 20,000 years ago from pyroxene andesite flows and has since been intruded by a hornblende dacite dome.

Black Butte from Weed, California

Since then the Shastina cone has been built by mostly pyroxene andesite lava flows. 9500 years ago these flows reached some 6.8 miles (11 km) south and three miles north of the area now occupied by nearby Black Butte (see below). The last eruptions formed Shastina's present summit about a hundred years later. But before that, Shastina, along with the then forming Black Butte dacite plug dome complex to the west, created numerous pyroclastic flows that covered 43 mile² (110 km²), including large parts of what is now Mt. Shasta, California and Weed, California. 400 ft (120 m) deep and quarter-mile (400 m) wide Diller Canyon is an avalanche chute that was probably carved into Shastina's western face by these flows.

Avalanche Gulch on Mt Shasta

The last to form and highest cone, the Hotlum Cone, formed sometime before 8000 years ago. It is named after the Hotlum glacier on its northern face and its longest lava flow, the 500 ft (150 m) thick Military Pass flow, extends 5.5 miles (9 km) down its northwest face. Since its creation a dacite dome intruded the cone and now forms the summit. The rock at the 600 ft (180 m) wide summit crater has been extensively hydrothermally altered by sulfurous hot springs and fumaroles there (only a few examples still remain).

In the last 8000 years, the Hotlum Cone has erupted at least eight or nine times. About 200 years ago the last significant Shasta eruption came from this cone and created a pyroclastic flow, a hot lahar (mudflow), and three cold lahars, which streamed 7.5 miles (12 km) down Shasta's east flank via Ash Creek. A separate hot lahar went 12 miles (19 km) down Mud Creek.

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Volcanic hazards

Diller Canyon on Mt Shastina from Weed, California

During the last 10,000 years Shasta has erupted an average of every 800 years but in the past 4500 years the volcano has erupted an average of every 600 years. The last significant eruption on Shasta may have occurred 200 years ago.

Mount Shasta can release volcanic ash, pyroclastic flows or dacite and andesite lava. Its deposits can be detected under two nearby small towns totalling 20,000 in population. Shasta has an explosive, eruptive history. There are fumaroles on the mountain, which show that Shasta is still alive.

The worst case scenario for an eruption is a large pyroclastic flow, such as what occurred in the 1980 eruption of Mount St. Helens. Since there is ice, lahars would also result. Ash would probably blow inland, perhaps as far as eastern Nevada. There is a small chance that an eruption could also be bigger resulting in a collapse of the mountain, as happened at Mount Mazama in Oregon, but this is of much lower probability.

The US Geologic Survey considers Shasta a volcano with a high probability of erupting again.

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Religion

Mt. Shasta from Little Mount Hoffman

Native American lore of the area held that Shasta is inhabited by the spirit chief Skell who descended from heaven to the mountain's summit. Since then, many other faiths, particularly New Age groups, have been attracted to Shasta -- more than any other Cascade volcano. Mt. Shasta, California, a small town near Shasta's western base, is a focal point for many of these religions. According to the Forest Service as reported in documentaries such as In The Light of Reverence, local Indian tribes, particularly but not limited to the Wintu, still practice healing rituals at the springs that flow from the mountain, and there is constant low-level conflict between the Indians and the New Age groups which have laid claim to the area as their personal sacred site.

The history of New Age fascination with Mount Shasta can be traced to the publication of Frederick Spencer Oliver's fantasy novel A Dweller On Two Planets. An indifferent, unmotivated student who was often ill, Oliver composed the novel at the age of seventeen. According to the foreword, his parents were awestruck that he could have engaged in such a sustained endeavor, and believed the novel to have been divinely inspired. They promoted it as a work of channeled wisdom, and it is still in print today. The novel is about the Lemurian race, who traveled to Mount Shasta when their continent sank beneath the ocean and are now said to live inside the mountain in a series of tunnels. In the years subsequent to the publication of Oliver's book, many seeking people claimed to have encountered Lemurians at Shasta.

Guy Ballard's I Am Activity and Elizabeth Clare Prophet's Church Universal and Triumphant are probably the best-known among numerous groups to attempt to participate in, or redefine, Shasta's spiritual heritage. Many of these cults hold that races of sentient beings, ostensibly superior to humans, live in or on Shasta, or visit the mountain in UFOs. In fact, Lenticular clouds sometimes form over the mountain. This is a fairly typical meteorological phenomenon over high places on the earth, which is often seen and mistaken for unidentified flying objects.

Mt. Shasta is also the site of a Buddhist monastery, Shasta Abbey, founded by Houn Jiyu-Kennett in 1971.

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Cultural references

Mt. Shasta is mentioned in Lost Legacy, a speculative fiction short story by Robert A. Heinlein as the home of a group of men who are masters of psychic powers and who decide to teach the world their powers by enlisting Boy Scouts.
The mountain is also part of a key scene in Ken Grimwood's novel Replay.

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