70 terms

Science Chapter 4 ROCKS

7th grade
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Terms in this set (...)

rock cycle
Describes how one type of rock can change into another type.
ingenuous rocks
Rocks formed from cooled and hardened magma or lava , Basaltic
metamorphic rocks
Made when heat, pressure, or fluids change one type of rock into another type of rock, - Any rock exposed to tremendous heat and pressur
sedimentary rocks
Formed when particles of broken rock and organic materials are pressed and cemented together to form new rocks. Sediments are mud, sand, pebbles, shells, bones, leaves, and stems. Some rocks of this type can be sandstone, limestone, and gypsum., Forms wen sediments such as muds, sands, or gravels are compressed by overlying sediments
how do rocks differ from minerals
rocks are substances made from a variety of materials including minerals such as volcanic glass, organic matter, quartz, feldspar, mica or calcite
major process of rock cycle
Earth has a dynamic system. Lithosphere floats on a molten mantle. Rocks are created and the re-melted in an ongoing process. There's no sample of rock unchanged since the Earth was formed. Molten magma cools and forms igneous rocks. Tectonic processes uplift the rocks exposing them to weathering process. Igneous rocks are broken down into granular material, that are transported and deposited to form sedimentary rocks (tectonic basins). Sediments buried and subjected to heat and pressure create metamorphic rocks. Heated sufficiently to melt forming magma.
magma
Hot, melted rock material beneath Earth's surface
sediment
Formed when particles of sand, dust, or soil, are deposited in horizontal layers
lava
WHAT MAGMA IS CALLED ONCE IT REACHES THE EARTH'S SURFACE.
intrusive
A type of igneous rock that generally contains large crystals and forms when magma cools slowly beneath Earth's surface, Igneous bodies that have crystallized within the crust.
extrusive
Eruption of magma and ash onto the Earth's surface where they cool to form lava flows and ash deposits., Extrusive Igneous rocks are formed on the surface of earth form lava. They have small or no crystals because they form quickly.
ingenuous rock classification
classified according to their mineral compound
basaltic rocks
dense, dark-colored rocks tht form from magma that is rich in iron and magnesium and poor in silica. The lava forming these rocks is fluid and flows freely from volcanoes in Hawaii EX: Gabbro, Basalt, Scoria
granitic rocks
light-colored rocks that have high silica content and contains mostly quartz, potassium feldspar, and plagioclase feldspar, light-colored igneous rocks with a lower density than basaltic rocks, Igneous rocks that are light-colored and low density. They form from magma that is thick and stiff and contains lots of silica
andesitic rocks
rocks that have mineral compositions between basaltic and granitic rocks. These rocks were formed from volcanoes found around the rim of the Pacific Ocean EX: Diorite, Andesite, Medium color, medium density, Granitic and basaltic rocks
volcanic glass
a rock that forms when lava cools too quickly to form crystals., pumice, obsidian, and scoria are all types of ____
foliated
: metaphoric rock, such as slate and gneiss, whose minerals grain flatten and line up in parallel layers, Metamorphic rock with visible bands or stripes
nonfoliated
Describes metamorphic rocks that lack distinct layers or bands., Marble & quartzite are what type of metamorphic rock?
pressure
Force per surface area where the force is normal to the surface: measured in pascals.
classifying metamorphic rocks
Based on mineral composition and texture. Meta rocks are either foliated or non foliated. Foliated is when the crystals are arranged in bands, and non foliated has grains in random orientations.
marble
A hard crystalline metamorphic rock that takes a high polish, Coarse, crystalline; Parent rock was limestone or dolostone; Composed essentially of calcite or dolomite crystals; Used as a decorative and monument stone; Exhibits a variety of colors
hot fluids in rock
mostly water with dissolved elements and compounds can react chemically with a rock and changes its composition especially when the fluid is hot
heat and pressure
Two processes that occur in order for a rock to be changed into a Metamorphic rock
sediments
Loose materials such as rock fragments, mineral grains, and bits of shell that have been moved by wind, water, ice, or gravity
stacked rocks
sedimentary rock in which older rocks, unless disrupted, are on the bottom, this forms in layers with the oldest layer at the bottom.
compaction
PROCESS THAT FORMS SEDIMENTARY ROCKS WHEN LAYERS OF SEDIMENTS ARE COMPRESSED BY THE WEIGHT OF THE LAYERS ABOVE THEM...
cementation
Calcite(most common) precipitates out of fluid between grains in order to glue grains together., The process by which dissolved minerals crystalize and glue particles of sediment together into one mass.
shape and size of sediment
clay, silt, sand, gravel - sediment is named according to the shapes and size of the sediments
what materials are found in sedimentary rocks
quartz, feldspar, calcite, gneiss, granite limestone
chemical sedimentary rocks
Sedimentary rock that forms when minerals precipitate from a solution or settle from a suspension.
limestone
CaCO3, Composition: Calcite. Origin: organic or chemical, sedimentary, warm shallow seas or dried bodies of water., A type of sedimentary rock often found near oceans & lakes
rock salt
Halite, Formed from residues of salt that remain after evaporation of water from salt lakes
organic sedimentary rocks
Sedimentary rock that forms from the remains of plants or animals., Sedimentary rock that forms from the remains of plants or animals. (Coal, Fossiliferous Limestone)
chalk
A type of limestone; a powdery, fine-grained rock composed of almost pure calcite.
coal
composed of the remains of plants that lived in tropical swamps millions of years ago
why does magma tend to rise toward earth's surface?
It is less dense than surrounding rocks
during metamorphism of granite into gneiss, what happens to minerals?
They align into layers
which rock has large mineral grains?
granite
what does igneous rocks form from?
magma
what sedimentary rock is made of large angular pieces of sediments?
conglomerate
which is an example of detrital sedimentary rock?
breccia
what is molten material at earth's surface called?
lava
what is an organic sedimentary rock?
coquina
james hutton
realized that rocks undergo changes through long periods of time after observing rocks at siccar point, Scotland
during which process do minerals precipitate in the spaces between sediment grains?
Compaction
which rock often is sculpted to create statues?
marble
which is an example of metamorphic rock?
granite
which rock consist mostly of seashell?
coquina
which process in the rock cycle causes magma to form?
melting
what forms when rocks are weathered and eroded?
sediments
which type of rock forms because of high heat and pressure without melting?
metamophic
what is a rock?
a naturally formed solid aggregate (mixture) of minerals, mineraloids, glass, or organic matter forming the Earth's crust
how is a rock different from a mineral?
Minerals are made up of particles with a repeating pattern called crystals. Rocks are made up of one or more minerals.
why are some igneous rocks are coarse and others fine?
some are coarse grained because the rock cools slow so crystals have time to form. Some are find grained because the rock cools quick so minerals have little time to form.
what is foliation?
Foliation is an arrangement of minerals in flat or wavy parallel bands.
How does foliation form?
Foliation is usually formed by the preferred orientation of minerals within a rock. also occurs because the rock has inequant mineral crystals that are parallel, or bc the rock has alternating dark and light colored layers
how does rock salt form?
By the evaporation of salty water, this contains dissolved Na+ and Cl- ions.
how is the formation of chemical sedimentary rocks similar to the formation of cement in detrital sedimentary rocks?
Both of the formative processes rely on minerals in solution for cementation.
What two minerals are most important in detrital sedimentary rocks?
Clay minerals and quartz are the chief constituents of most sedimentary rocks in this category
What are the similarities between the formation processes of igneous sedimentary and metamorphic rocks?
Both processes utilise pressure and heat in their formation. Igneous is formed by magma being cooled and compressed beneath the earth's surface or lava cooling on the top, and metamorphic is formed by extremely high pressures and heat beneath the earth's surface. Sedimentary rock is different because it is formed by the accumulation of sediments of clay and soil on or slightly below the surface of the Earth.
What is the first process that occurs in the formation of sedimentary rocks?
Although sedimentary rocks form in a variety of processes, the first process that would occur in the formation of the most common sedimentary rocks would be that of weathering, which is the breakdown of rocks into smaller pieces through chemical or mechanical means by nature.
How do detrital and chemical and organic sedimentary rocks differ from one another?
Detrital: A sedimentary rock composed of lithified sedimentary particles of previous rock types.

Chemical: A sedimentary rock created by the evaporation and subsequent crystallization of mineral rich fluids.

Organic: A sedimentary rock composed of the remains of lithified plants (coal), or animals (limestone).
Chemical rocks originate from a chemical solution. Detrital rocks are made up of fragments or other rocks. Organic rocks are made up from organic material.
why is the rock cycle called a cycle?
rock material is constantly being recycled into different forms or back to magma
why does pressure increase with depth in earth?
the more water is being pulled by Earth's gravitational force, and this cause the Pressure is directly proportional to depth. So the farther down you go the more pressure.
How does higher pressure affect rocks?
When rocks are subjected to high pressures, they can change their formation and appearance. This process, which alters the structure of a rock, is called metamorphism.
What two things happen to sediment to turn it into sedimentary rocks?
the sea erodes away sediments of rock and the sediments lay on the sea floor, after time the weight of the sediments pushes the water out and forms sedimentary rock.
Why is slate used for roofs?
Slate is a natural stone formation that splits easily into thin sheets. A sheet of slate can be cut into shingles that provide excellent protection against rain and melting snow, and are highly resistant to damage by wind. Slate roofs are subject to damage by very large hail stones
What rocks are used for important purposes in society?
Precious and semi precious gemstones, for one. They are obviously important in our social structure, and are a major trade item.
Granite, limestone, slate and marble are all used for architectural purposes as well as for tombstone material.
How are organic and chemical rocks the same and different?
Both organic sedimentary (like coal) and chemical sedimentary (like rock salt) rocks are not composed of particles of other rocks. They are different because organic rocks are composed of the remains of living things but chemical rocks are formed by inorganic processes such as evaporation.
is coquina classified in more than one way
Because it forms from animals that were once living which makes it an organic sediment. It can also be classified into the Detrital sedimentary rock category because it is compacted together.