Beach sand formed by ocean waves grind rocks into tiny grains over an extremely long time
Earth:
Earth formed approximately 4.54 billion years ago when a disk of debris gathered into a rocky sphere, a process known as accretion.
Earth’s deepest man made borehole is 12,262 meters (40,230 feet) deep
• Russia’s Kola Superdeep Borehole reached a depth of 12,262 meters in 1989 and has never been surpassed.
Earth’s moon –
While it’s not the only theory, geologists think a planet the size of Mars may have impacted Earth and created the moon not long after Earth formed.
Magnetic field – the movement of liquid iron in the outer core
The process that creates the magnetic field is complex, but it is caused by molten iron in the outer core moving due to heat convection from the hotter, solid inner core.
Shape: an oblate spheroid
An oblate spheroid is a squashed sphere – Earth is slightly flatter at the poles and bulges at the Equator.
Mantle – The part of Earth that lies just beneath the crust. The mantle “flows” over an extremely long time, but it primarily consists of solid rock.
As you go deeper into Earth, the temperature gets hotter
The temperature of the mantle ranges from 1832 F (1000 C) to 6692 F (3700 C).
Pangea – Earth’s continents were once joined as a single massive supercontinent.
The Greek name Pangaea can be roughly translated to English as “whole Earth.”
Seismologists map Earth’s interior by seeing different types of waves from earthquakes propagate through areas of different density within the interior.
Earthquakes waves move differently through different materials, which is how seismologists know the outer core is liquid and the mantle slowly shifts via convection.
Asteroid impacts –
A widely accepted theory suggests that mass extinctions have been caused by asteroid impacts. Evidence to support this theory are remnants of massive impact craters on the surface.
The remnants of enormous impact craters, some of them 100 miles (161 kilometers) or more in diameter, can be found worldwide, with some of the largest in South Africa, Canada and Mexico.
Barrier islands are uncemented sediments that form islands along ocean shorelines
Barrier islands are often made of sand dunes and other loose material, and they can shift, change or disappear during storms. They help protect shorelines from erosion and storm surges.
Continental shields are composed of: Very old and intensely deformed igneous and metamorphic rock
Divergent boundary – the boundary between two tectonic plates where they are moving away from each other.
Divergent boundaries witness the separation of tectonic plates, often leading to the formation of mid-ocean ridges.
Geysers are caused by groundwater heated by magma that becomes superheated and flashes into steam
Geysers require specific “plumbing” (usually a lower chamber with a constrained opening at the surface) for the water to become superheated.
Hawaii: U.S. state was formed by a hotspot of magma that was fed to the crust from the mantle
The magma was cooled by ocean water, forming the Hawaiian islands.
Igneous Rock – formed from the cooling and solidification of magma or lava
Igneous rocks, like granite and basalt, originate from the cooling and solidification of molten materials.
Impactite – type of rock that can only be formed from the sudden shock and heat of a meteorite impact.
Impactites are considered metamorphic even though they don’t form over the millions of years required for most metamorphic rocks.
Lake Missoula – 15,000 years ago the collapse of an ice dam caused it to catastrophically flood the surrounding area.
It’s believed that ice dam formation and collapse caused several massive floods during the last ice age, unleashing incredible energy and reshaping the surrounding area.
Limestone:
Rock commonly associated with areas known as karst and characterized by extensive cave systems
Limestone is highly soluble in water compared to other forms of rock. Water erodes passages through limestone and creates the caves and other features common to karst topography
The Mariana Trench – unique geologic feature formed by the subduction of the Pacific Plate beneath the Mariana Plate
The deepest part of the Mariana Trench is nearly seven miles below the surface of the ocean.
Metamorphic rock – a type of rock formed by extreme pressure and heat over a long time
Examples of metamorphic rock include gneiss and marble.
The Mesozoic Era, spanning from approximately 252 to 66 million years ago, is often referred to as the “Age of Dinosaurs.”
Mid-Atlantic Ridge crust is spreading at a rate of approximately 2.5 centimeters each year as tectonic plates move away from each other because it’s a divergent boundary between the North American and Eurasian tectonic plates as well as the South American and African plates.
Minerals
Cinnabar is mercury sulfide, an incredibly toxic chemical. You should never handle cinnabar, much less taste it. It is notable for being the deadliest mineral on Earth.
Halite is a mineral that precipitates from oceans and forms rock salt
Halite forms when salty bodies of water dry up, leaving salt deposits that can be hundreds of meters thick.
Moraines are geologic features that can form ridges, rolling hills or wedge-shaped areas. Former by the process of glaciers depositing debris as they advance, melt and retreat
Glaciers scoop rocky debris from the ground and slowly carry it forward, eventually depositing the debris when the glacial ice melts.
Niagra Falls – Erosion has caused the waterfall to retreat more than 10 kilometers (6.2 miles) in the last 10,000 years.
Pahoehoe is a type of lava flow
Pahoehoe is pronounced “pah-hoey-hoey” and is a term of Hawaiian origin.
Post-glacial rebound – when the crust gradually lifts back up after being depressed by the incredible weight of glacial ice
During the last glacial period, glacial ice in Europe and North America was up to 3 kilometers (1.9 miles) thick. The incredible weight pushed down on the crust, and in some areas the crust is still springing back into shape.
Pyrite – with its brassy color and metallic sheen, is often mistaken for gold, earning it the nickname “fool’s gold.”
Richter scale – the scale used to measure the magnitude of earthquakes
Ring of Fire – an area around the perimeter of the Pacific Ocean characterized by frequent, intense seismic activity
The series of active tectonic plate boundaries surrounding the Pacific Ocean accounts for the majority of the world’s earthquakes and volcanoes.
Sedimentary rock
Coal – sedimentary rock formed when plant matter is buried and compressed over millions of years. It has been used as a fuel for thousands of years.
Transported Soil – Soil that does not match the age or composition of the underlying bedrock it sits upon
Transported soil is moved by erosion and gravity. Its origin can often be found uphill, but wind can carry transported soil hundreds or thousands of miles, even across oceans.
Weathering – the process by which rocks are broken down into smaller particles by natural forces
Weathering is the gradual breakdown of rocks into smaller particles through processes like mechanical abrasion and chemical decomposition.
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