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Snoqualmie Falls Volcano

A cache by Forty-n-Eight Send Message to Owner Message this owner
Hidden : 10/26/2009
1.5 out of 5
1.5 out of 5

Size: Size:   not chosen (not chosen)

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Geocache Description:

This cache is located at Snoqualmie Falls. This area is suitable for all ages and offers trails, picnic tables, bathrooms, and even a gift shop.

To log this cache, please do two things:

1. Locate a volcanic bomb and try to identify the type of bomb from the descriptions below. Email your guess of the bomb type to the cache owner. Note you will likely have to go to the bottom of the falls to find a bomb.

2. Include two (2) pictures in your log...a picture of yourself in front of the falls and a picture of your bomb.

Snoqualmie Falls is a 268 ft (82 m) waterfall on the Snoqualmie River between the towns of Snoqualmie and Fall City. More than 1.5 million people visit the falls every year and enjoy the two acre park. There is a trail from the upper park to the lower park, where you can walk along a boardwalk past the PSE power plant to a viewing platform at the bottom of the falls.

For the Snoqualmie People, who have lived for centuries in the Snoqualmie Valley in western Washington, Snoqualmie Falls is central to their culture, beliefs, and spirituality. A traditional burial site to the Snoqualmie Tribe, the falls are "the place where First Woman and First Man were created by Moon the Transformer" and "where prayers were carried up to the Creator by great mists that rise from the powerful flow." The mists rising from the base of the waterfall are said to serve to connect Heaven and Earth.

THE VOLCANO from the SnoValley Star
Geologists recently discovered that the Falls flow over a 20 million year old extinct volcano. A team led by Washington’s DNR geologists recently found that the volcanic rock in the Snoqualmie Valley was more local and younger than previously thought. Until recently, geologists had attributed the Valley’s volcanic rock to Mount Persis, an extinct volcanic area to the north in Gold Bar. A closer examination showed the Valley’s volcanic rock are about 20 million years younger than the 40-50 million year old rock of Mount Persis.

A few key observations helped geologists come to their conclusions. When volcanoes spew lava, gas, and earth, the heavier material can’t travel as far as the lighter matter. The heavier content – called volcanic bombs when larger than 2.5 inches in diameter but can be much larger – acquires a round shape during flight and the subsequent landing. Geologists found hundreds if not thousands of volcanic bombs near the falls, suggesting the center of the volcano was nearby. Also, the entire Falls area is dominated by lava flows and the flows usually don’t move very far from the volcano, according to geologists.

While recent glacial and seismic activity make it hard to pinpoint, geologists are confident the center of the volcano lies very near the Falls. Visitors can see evidence of the volcano by walking down to the wooden platform across from the base of the falls. A careful eye will spot volcanic bombs across the Snoqualmie River.

Bombs are named according to their shape, which is determined by the fluidity of the magma from which they are formed.

Ribbon or cylindrical bombs form from highly to moderately fluid magma, ejected as irregular strings and blobs. The strings break up into small segments which fall to the ground intact and look like ribbons. Hence, the name ribbon bombs. These bombs are circular or flattened in cross section, are fluted along their length, and have tabular vesicles.

Spherical bombs also form from high to moderately fluid magma. In the case of spherical bombs, surface tension plays a major role in pulling the ejecta into spheres. Spindle, fusiform, or almond/rotational bombs are formed by the same processes as spherical bombs, though the major difference being the partial nature of the spherical shape. Spinning during flight leaves these bombs looking elongated or almond shape, the spinning theory behind these bombs' development has also given them the name 'fusiform bombs'.

Spindle bombs are characterised by longitudinal fluting, one side slightly smoother and broader than the other. This smooth side represents the underside of the bomb as it fell through the air.

Cow pie bombs are formed when highly fluid magma falls from moderate height (so the bomb does not solidify before impact) which are still liquid when they strike the ground. They consequently flatten or splash and form irregular roundish disks which resemble cow-dung.

Bread-crust bombs are formed if the outside of a lava bomb solidifies during its flight, it may develop a cracked outer surface as the interior continues to expand.

Cored bombs are bombs that have rinds of lava enclosing a core of previously consolidated lava. The core consists of accessory fragments of an earlier eruption, accidental fragments of country rock or in rare cases bits of lava formed earlier during the same eruption.

Additional Hints (Decrypt)

Ybbx sbe ynetr obhyqref ba gur bccbfvgr fvqr bs gur evire.

Decryption Key


(letter above equals below, and vice versa)

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