The amount of argon occluded is probably a function of the argon pressure when mineral crystallization occurred at depth and/or the tightness of the mineral structure.
Fiery illusion: Mid-February sunsets in Yosemite National Park lights a natural firefall from Glacier Point illuminating one of the park's lesser-known waterfalls so precisely that it resembles molten lava Every year growing numbers of photographers converge on the park, their necks craned toward the ephemeral Horsetail Fall, hoping the sky will be clear so they can duplicate the spectacle first recorded in color in 1973 by the late renowned outdoors photographer Galen Rowell.
Captured: The waterfall called Horsetail Fall, geographically situated perfectly to capture the February sunset, was first recorded in color in 1973 by the late renowned outdoors photographer Galen Rowell But photographing Horsetail is a lesson in astronomy, physics and geometry as hopefuls consider the azimuth degrees and minutes of the earth's orbit relative to the sun to determine the optimal day to experience it.
After three of these explosive eruptions (June 12, August 7 and October 17), near-surface magma had low enough steam pressures so that viscous lava flows formed three consecutive, dome-shaped structures within the crater.
The first two dacite lava domes built within the crater (late June and early August 1980) were destroyed by subsequent explosive eruptions (July 22 and October 17).
(Note that solids, even though they appear solid have a viscosity, but it very high, measured as trillions time the viscosity of water).
Viscosity is an important property in determining the eruptive behavior of magmas.
Cinder Cone is a cinder cone volcano in Lassen Volcanic National Park (located in Northern California in the United States).
It is located about 10 miles (16 km) northeast of Lassen Peak and provides an excellent view of Brokeoff Mountain, Lassen Peak, and Chaos Crags.
They are looking for the lowest angle of light that will paint Horsetail the colors of an iridescent sunset as rays reflect off granite behind the water.
It materializes in varying degrees of intensity for the same two weeks every year.