Geology & Geologic Time
This is the term for molten rock found beneath Earth's surface.
What is magma?
This force keeps planets in orbit around the Sun and gives objects weight on Earth.
What is gravity?
This air mass type, abbreviated "mP," forms over cold ocean areas and brings cool, moist weather.
What is a maritime Polar air mass?
This type of plate boundary can create mountains.
What is a convergent plate boundary?
The continuous recycling process connecting igneous, sedimentary, and metamorphic rocks.
What is the Rock Cycle?
Scientists use this process, in which unstable isotopes decay at a known rate, to determine the absolute age of rocks.
What is radioactive (radiometric) dating?
This shift of light toward longer wavelengths, observed from distant galaxies, is key evidence for the expanding universe.
What is red shift?
The atmospheric layer above the troposphere that contains the ozone layer.
What is the stratosphere?
At this type of boundary, two plates move apart and magma rises to form new oceanic crust.
What is a divergent boundary?
This mineral property, measuring resistance to scratching, is quantified on the Mohs scale.
What is hardness?
This era, known as the "Age of Reptiles," spans from about 252 to 66 million years ago and includes the Triassic, Jurassic, and Cretaceous periods.
What is the Mesozoic Era?
On the H-R Diagram, most stars — including the Sun — fall along this diagonal band.
What is the Main Sequence?
This type of front forms when a cold front overtakes a warm front, lifting the warm air mass off the ground.
What is an occluded front?
The supercontinent that existed approximately 225 million years ago, proposed by Alfred Wegener.
What is Pangaea?
This sedimentary rock, made of sand-sized particles, is the most common clastic sedimentary rock.
What is sandstone?
On the Geologic Time Scale, these are the largest divisions of time — Hadean, Archean, Proterozoic, and Phanerozoic.
What are Eons?
This model, proposed by Copernicus, places the Sun at the center with planets orbiting around it.
What is the heliocentric model?
The Coriolis effect causes winds to deflect to the right in this hemisphere.
What is the Northern Hemisphere?
This seismic wave compresses and expands rock in the direction it travels and can move through solids and liquids.
What is a P-wave (Primary wave)?
This type of igneous rock forms from lava cooling quickly on Earth's surface, resulting in small crystals or a glassy texture.
What is extrusive (volcanic) igneous rock?
A sample has 25% of its original C-14 remaining. How many half-lives have passed?
Two half-lives (≈11,460 years).
This is the term for the point in Earth's orbit when it is closest to the Sun, occurring around January 3rd.
What is perihelion?
This is the primary reason New York State experiences four distinct seasons.
What is Earth's axial tilt (23.5°)?
This type of boundary, like the San Andreas Fault, produces earthquakes but no volcanism or mountain building.
What is a transform boundary?
This mineral, the hardest on the Mohs scale, cannot be scratched by any other natural mineral.
What is diamond (hardness 10)?