Shared Flashcard Set

Details

Rocks
igneous, metamorphic, and sedimentary rocks
36
Geology
6th Grade
12/16/2007

Additional Geology Flashcards

 


 

Cards

Term
rock
Definition
made of combined minerals
Term
coal
Definition
made up of the remains of ancient plants that have been buried and pressed into rock
Term
rocks change as they
Definition
break apart, wear away; pressed and heated together; melt
Term
obsidian
Definition
a rock not made of minerals; natural glass; no crystal structure; igneous rock
Term
igneous rock
Definition
forms when MOLTEN ROCK COOLS and becomes a SOLID
Term
metamorphic rock
Definition
forms by heat and pressure
Term
metamorphic rock
Definition
can be raised to Earth's surface over time
Term
intrusive rock
Definition
granite and gabbro; forms when magma cools WITHIN Earth
Term
extrusive rock
Definition
Rhyolite, pumice, and basalt (found on ocean floor); forms when LAVA cools on Earth's surface
Term
intrusive rock crystal size
Definition
LARGE crystals form because the HIGH temperatures allow MAGMA to cool SLOWLY which allows time for LARGE crystals to form
Term
extrusive rock crystal size
Definition
VERY SMALL crystals form because LOWER temperature on Earth's surface allow LAVA to cool QUICKLY
Term
How did the Ship Rock Form?
Definition
Formed below the Earth's surface 30 million years ago from cooled magma from a volcano. As magma pushed upward, it made formations and channels. The surface rock was worn away to reveal this large rock formation.
Term
What kind of rock makes up Ship Rock in New Mexico?
Definition
Intrusive Igneous Rock
Term
How does a cone shaped volcano form?
Definition
Pressure builds and LAVA that is rich in SILICA explodes; this volcano has steep sides; Ex. Mt. St. Helens;
Term
How is a volcano with sloping sides formed?
Definition
LAVA that is LOW in SILICA flows in thin sheets. It builds huge volcanoes with sloping sides; Ex. Hawaiian Islands
Term
How do geologists classify rock?
Definition
by how rich the rock is in SILICA
Term
What determines the color of igneous rock?
Definition
the level of silica
- low levels of silica are DARK in color, like gabbro and basalt
-high levels of silica are LIGHT in color like granite and rhyolite
Term
How are rock particles broken away from larger rocks?
Definition
by wind, water, or both
Term
How can sediment be changed into rock?
Definition
as rock particles settle on land or at the bottom of rivers, lakes, and oceans SEDIMENTS form LAYERS of larger and smaller particles that are PRESSED together by the overlaying LAYERS to form conglomerate, sandstone, or shale.
Term
Conglomerate rock is what kind of rock?
Definition
Sedimentary rock.
Term
Sandstone and shale are what kind of rock?
Definition
Sedimentary rock.
Term
Coal is what kind of rock?
Definition
Sedimentary rock not made from sediments,but made from the ancient remains of plants
Term
What kind of rock is limestone?
Definition
Sedimentary rock that is formed by the shells and skeletons (calcite) that settle on the ocean floor as layers that are buried, PRESSED and CEMENTED together
Term
How is rock salt formed?
Definition
it is formed where minerals CRYSTALIZE along the edges of lakes and oceans where the climate is dry and a lot of water EVAPORATES quickly
Term
What kind of rock is rock salt?
Definition
sedimentary rock
Term
The oldest layers of sedimentary rock are found on what layer?
Definition
the bottom layers
Term
What kind of layers does a flood create?
Definition
The largest particles are at the very bottom of the layer. Particles higher in the layer become increasingly smaller. The shows the the water carrying the sediment was slowing down.
Term
How can geologists tell the direction in which water or wind was moving from rock?
Definition
- tilted layers called crossbeds on the slopes of sand dunes or sandbars
-ripples in the surface
-mudcracks on the surface
Term
What is metamorphism?
Definition
the process in which an existing rock is changed by heat or pressure or both
Term
What are the original parent rocks of metamorphic rock?
Definition
sedimentary or igneous rock and even metamorphic rock
Term
what is recrystallization?
Definition
the process by which heat and pressure break the bonds that join atoms in minerals.
Term
What happens during recrystallization?
Definition
-first, individual mineral crystals can grow larger as more atoms join their crystal structures
-second, atoms combine in different ways to form new minerals in the place of old ones; Ex. shale (sedimentary rock) recrystallizes to form garnet (metamorphic rock)
Term
Why do rocks buried deeper in the crust change?
Definition
they change because pressure and temperature increase with depth
Term
folliation
Definition
an arrangement of minerals in flat or wavy parallel bands
Term
What happens to the minerals in a foliated rock?
Definition
minerals FLATTEN out or LINE UP in BANDS under PRESSURE
Term
How do nonfoliated rocks form?
Definition
mineral crystals are NOT lined up and the parent rock is made up of 1 mineral; Ex. marble and quartzite
Supporting users have an ad free experience!