Mountain Formation and Types of Rocks

Mountain Formation

• Mountains are high geologic features rising above surrounding land.
• Hills, mounds, and plateaus are smaller, similar formations.
• Mountains are composed of various rocks, metals, minerals, and gemstones, varying by location.
• Rocks are made of minerals, which are made of elements.
• Gemstones are minerals with special properties creating value.
• Rocks on Earth primarily consist of oxygen and silicon.

Types of Mountain Rocks

• Igneous rock: Forms when molten rock (magma) cools and hardens, often having a smooth texture. Formed by volcanic activity.
• Sedimentary rock: Forms from compressed sediment (small rocks). Shows layered structures.
• Metamorphic rock: Forms when igneous or sedimentary rocks undergo changes due high pressure or heat.

How Mountains Form

• Most mountains are formed by the collision of continental tectonic plates.
• Plate collision can occur rapidly, like a crash, or gradually over time, causing continuous growth.
• Mount Everest rises approximately 0.16 inches yearly due to the pressure of converging Eurasian and Indian plates.
• Mount Everest also moves slightly north, about two inches annually, due to uneven pressure.
• The Himalayas are examples of fold mountains, formed where plates collide.

Orogeny

• Orogeny: Scientific term for mountain formation.
• Mountain formation is typically caused by tectonic plate interaction at plate boundaries.
• Volcanoes can also cause mountains, through buildup of erupted material.

Major Mountain Types

• Fold Mountains: Form when two continental plates move toward one another.
• Fault-Block Mountains: Form when faults in Earth's crust force rock upwards, resulting in steep cliffs.
• Volcanic Mountains: Form from repeated eruptions from a single vent, building up layers of igneous rock. Example: Mount Fuji.
• Dome Mountains: Magma rises close to the surface, but doesn't erupt; cools and hardens into a dome shape.
• Erosion Mountains: Form slowly through differential erosion, with some rock materials worn away faster than others.
• Hotspot Mountains: Form when magma rises from deep within the earth and the land moves/erodes over it. Not found at plate boundaries, Example: The Hawaiian islands.
• Some mountains are found at the boundary of ocean plates, not necessarily hotspot formations.

Additional Information

• Mauna Kea, measured from base to peak, is the tallest mountain on Earth (33,474 feet).
• The majority of its height is below sea level.