Andesite may be used as aggregate or fill, but it is not ideal for concrete applications because it is high in silica, and causes alkali-silica reactivity in the concrete. Andesitic volcanism is associated closely with porphyry copper deposits and it is a host rock for much of the world’s copper ore.

Dissolved Gas and Explosive Eruptions

• Water vapor produced when ocean-floor sediments on an oceanic plate are heated in a subduction zone.
• Water vapor produced when hydrous minerals dehydrate in the heat of a subduction zone.

Mineral content – groundmass generally of pyroxene ( augite) and plagioclase, possibly with minor amounts of amphibole ( hornblende) and glass; phenocrysts of plagioclase and often pyroxene, occasionally olivine or amphibole.

Uses. Basalt is used in construction (e.g. as building blocks or in the groundwork), making cobblestones (from columnar basalt) and in making statues. Heating and extruding basalt yields stone wool, which has potential to be an excellent thermal insulator.

Basalt is a hard, black volcanic rock with less than about 52 weight percent silica (SiO2). Because of basalt’s low silica content, it has a low viscosity (resistance to flow). Therefore, basaltic lava can flow quickly and easily move >20 km from a vent.

Gold, as well as other rare metals, can be brought to the surface by plumes of molten rock from deep within the mantle, the layer underneath Earth’s crust, producing background levels of gold up to 13 times higher than elsewhere, according to research published Oct. 19 in the journal Geology.

While gold is sometimes found in extinct volcanoes, Dr. This is the first time scientists have detected visible gold particles in an active volcano. It is not known how much gold the volcano has produced since it began forming more than 500,000 years ago, Dr.

Scientists believe all the gold on Earth formed in supernovae and neutron star collisions that occurred before the solar system formed. In these events, gold formed during the r-process. Gold sank to the Earth’s core during the planet’s formation. It’s only accessible today because of asteroid bombardment.

Diamonds are brought to the surface from the mantle in a rare type of magma called kimberlite and erupted at a rare type of volcanic vent called a diatreme or pipe. Upper mantle xenoliths are found in some kimberlite and provide clues to the magma’s origin.

Lava won’t kill you if it briefly touches you. You would get a nasty burn, but unless you fell in and couldn’t get out, you wouldn’t die. With prolonged contact, the amount of lava “coverage” and the length of time it was in contact with your skin would be important factors in how severe your injuries would be!

Lava is molten stone that has a temperature range of 1,300 to 2,200 F. It can also range in consistency from extreme liquid, like water to a thick bubbling oatmeal consistency. If you touch it, it will feel like Hell for the few seconds it will take to vaporize your hand..