Types of Formations Environmnets
What continuous process describes how rocks transform from one type to another over geological time?
The Rock Cycle
This process involves dissolved minerals precipitating out of groundwater to "glue" loose sediments together.
cementation
This term refers to the original, unaltered parent rock before it undergoes metamorphism.
protolith
Lightweight and filled with gas pockets (vesicles), this extrusive igneous rock can actually float on water.
pumice
This surface process breaks down existing surface rocks into smaller sediment pieces through atmospheric exposure, wind, and water.
weathering
Powered by Earth’s internal heat, these rocks form from the cooling and crystallization of molten rock like magma or lava.
Igneous rocks
Wavy lines preserved on a rock surface indicate that the rock likely formed in water under the action of waves or currents.
ripple marks
This type of localized metamorphism occurs when existing rock is "baked" by adjacent magma intrusions with extreme heat but minimal directional pressure.
contact metamorphism
Formed when silica-rich lava cools so rapidly that atoms cannot arrange into a crystalline structure, this rock is also known as volcanic glass.
obsidian
According to Bowen's Reaction Series, this highly resistant mineral is the last to crystallize at lower temperatures and forms the primary component of most sandstones.
quartz
This primary process describes how loose sediments transform into solid rock through compaction and cementation.
lithification
A clastic rock made of large, rounded pebbles requires this level of kinetic energy in its ancient depositional environment to be transported.
a high-energy environment (such as a fast-moving mountain river)
Metamorphic rocks that feature a parallel alignment of minerals or a banded appearance due to directional pressure are known by this term.
foliated
When limestone is subjected to metamorphic heat and pressure, its calcite crystals recrystallize to form this non-foliated metamorphic rock.
marble
Molten rock material deep beneath Earth's surface is called magma, but it receives this name once it reaches or exits Earth's surface.
lava
Deep beneath the surface, a large body of magma cooled very slowly over thousands of years, forming large, visible crystals. What rock environment and texture is this?
an intrusive igneous rock with a phaneritic (coarse-grained) texture
Because clay particles settle out only in calm, still waters, this fine-grained clastic sedimentary rock forms in low-energy lake beds or deep ocean floors.
shale
When a shale protolith undergoes regional metamorphism, state the correct four-step sequence of rocks formed as metamorphic grade increases from low to high.
Slate ---> Phyllite ---> Schist ---> Gneiss
Made of the smallest sediment particles (clay) pressed into flat layers, this smooth clastic sedimentary rock easily splits apart.
shale
Rapid surface cooling causes extrusive igneous rocks to form this characteristic grain size compared to slow-cooling intrusive rocks.
fine-grained (or microscopic/tiny crystals)
In eastern Ohio, compressed carbon-rich ancient plant material that accumulated in stagnant, oxygen-poor swamps formed coal. What specific subtype of sedimentary rock is coal?
an organic sedimentary rock
These inclined, crisscrossing sedimentary layers are formed by migrating sand dunes in desert environments or strong water currents.
cross-bedding
When sandstone undergoes intense recrystallization, quartz grains interlock into an equant mosaic, forming this non-foliated metamorphic rock.
quartzite
Exhibiting a signature silky sheen due to microscopic mica growth, this low-to-medium-grade foliated rock represents the stage between slate and schist.
phyllite
During the Silurian period, these sedimentary deposits formed in northeastern Ohio when ancient shallow tropical seas periodically evaporated.
halite (or rock salt) beds