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____________ derived from weathering and erosion of other rocks.
__________ ______________ formed by chemical precipitation (ex. limestone, rock salt, chert)
Detrital Sedimentary rocks have a _______ texture, and are classified by ________ ______.
_________- conglomerate and breccia
- gravel sized
- silt sized
- clay sized
Sandstones formed at _____ ______ areas.
_______ is the most abundant sedimentary rock.
Chemical Precipitate rocks are classified by _______ _________.
CPOs can have either _______ or a __________ texture.
Travertine is _______ ______ limestone.
Rock salt forms in _____ ____ or ____ ____ in arid climates.
tidal pools; playa lakes
Coal is _________. And most coal forms in ____ oxygen conditions.
lithofied (plant matter); low
Water- most important, produces ________ sediments
Wind- produced ________ sorted sediments
Ice- glaciers drop _________ sediments. Glacial meltwaters produce _______ sediments.
Gravity- produces ________ sediments
Plate Tectonics- ___________ movements of large packages.
- well sorted
- very well
- poor sorted; well sorted
- poor sorted
- huge scale
_________- rivers, lakes, base of mountains, deserts, glaciers, swamps
_______- beaches, deltas, lagoons, marshes, reefs
_______- MORs, deep ocean, continental shelf and slope, trenches, subduction zones
__________- indicate alternating wet and dry conditions
___________ shoreline or Aeolian conditions
___________ indicate current direction or wave action
__________ records storm surges or high water episodes
___________ palontology and climate indicators.
- Ripple Marks
- Graded bedding
- Tracks and burrows
___________: The process of turning sediment into rock.
________ - sediment must be deposited
_________- sediment must be buried deeply enough for grains to settle
________- pressure causes grains to align to preferential directions
__________- in-filling of pore space by minerals in solution
When the shoreline moves landward, that is a __________ of the sea.
What are some causes?
- Melting of glaciers
- Displacement due to increased volcanism at MOR's
When the shoreline moves seaward, that is a _________ of the sea. What are some causes?
- Drop in sea level
- local uplift of the land
- Increase of glacier and polar ice caps
What is Weathering?
Weathering is a slow______________ and ___________ of rocks at or near the earth's surface. During weathering, the _________ (aka the original rock) is broken down into _______ pieces and some of the original minerals are altered or dissolved.
- physical breakdown; chemical alteration
- parent material
What is Erosion?
Erosion involves all processes that wear away rock and soil and ____________ the weathered material.
Weathering vs. Erosion
_________ involves NO transportation
_________ actually removes and transports the weathered material
The Two Main Types of Weathering
___________- takes place when physical forces break rock into smaller pieces, but still retain the composition of the parent material
___________- decomposition of rock through chemical reactions, most of which involves water
Types of Mechanical weathering:
- Frost Wedging
- Pressure release or Exfoliation
- Thermal heating and cooling
- Activities of organisms
Chemical weathering involves the ___________ of rock through chemical reactions, most of which involves ________.
________ occurs when rocks or minerals are dissolved, and involves acid rain or acidic conditions.
________ involves the combination of oxygen with certain elements, usually metals.
___________ process in which water is added to the crystalline structure of certain minerals so they become hydrated.
- decomposition; water
So what is the difference between dissolution and hydrolysis?
Dissolution- bonds are broken, some chemical components are _________ or ____.
Hydrolysis- solvent chemical components may be ___, but the minerals are ______.
- released; lost
- lost; changed
________ is composed of rock and sediment that has been mixed with organic matter and water. (it is also the most important product of weathering and erosion)
____________ soils that develop in humid regions (Eastern US/CA). They develop where moisture is abundant, chemical weathering is intense, but there is a rich litter of organic matter
________ soils that develop in arid and semarid climates (western US). This soil contains less organic matter and tends to be very thin.
__________ soils formed in the tropics and rain forests where chemical weathering is extremely intense and leaching of soluable minerals is complete. These soils are red, very thick, and are very fertile.
________ and ______ weather more rapidly than sandstones and conglomerates.
Metamorphic rocks are any type of _______________ rock that has been altered by a combination of heat, pressure and/or fluid activity. These agents cause changes in the mineralogy and in the "_______". Changes take place at ______ and provide us with information about processes deep in the earth. All changes are ________ changes, meaning the rock does not melt for these changes to happen.
Controlling factors of Metamorphism:
- parent material
- tectonic forces
- the effects of fluids, particularly water
Metamorphic rocks owe their characteristic texture and mineral content to the _____________ known as a __________.
Usually no new elements or compounds are added to the crystalline structure
Therefore the _______________ of the metamorphic rock is controlled by ____________.
- parent rock; protolith
- mineral composition; parent material
Heat for metamorphism comes from the outward flow of _________ from the Earth's core and mantle.
Heat can also comes from _______________ such as a deep burial within a subduction zone.
Nearness to a _____________ as it moves through the crust
- geothermal energy
- tectonic processes
- magma body
Minerals stable at higher temperatures tend to be less ______. This allows them to withstand __________ heat without melting.
The pressure experiences by rocks due to the weight of overlying and side rocks is _______________ pressure (also known as "confining pressure"). This pressure compresses rocks and makes them more dense
__________ pressure occurs when continents collide or at any ___________ plate boundary.
____________ (hot water) is the most important fluid involved in the metamorphism. The water may come from the _________ or be given off by a cooling ________. Water moves through ___________ and redistributes ions to change the mineralogy of the rock.
- parent rock; pluton
Metamorphism that is caused by contact with a magma body, most often at shallow depths the rocks are cold is called _________________________.
Different grades of metamorphic zones are marked by the presence of certain _______________. The closer the rocks are to the _____________, the more metamorphosed the rocks are. These zones are called ________.
- contact metamorphism
- index minerals
- contact zone
___________ are a dark gray fine-grained rocks that form at the contact zone.
Metamorphism that affects very large areas, usually associated with plate boundaries is called ____________ metamorphism.
Plate collisions cause directed stresses resulting in _____ areas with ___________ metamorphic rocks.
Metamorphism that happens in fault zones where rocks are ground up by the motion of fault rocks is called _______________ metamorphism.
This creates a distinctive texture in rocks called _________ fabric.
The rocks are strongly __________ with rotated crystals that show shearing.
Based on the direction of "wings", you can tell the direction of movement.
Changes in ___________. (ie, growths of micas, garnets, chlorite, and other index minerals)
Changes in _____________ refers to the size, arrangement of the particles. (ie rocks become more coarse-grained and grains sometimes align in sheets or layers.)
_______________ metamorphic rocks are strongly layered by directed pressure. (ex. Slate, Phyllite, Schist, Gneiss)
____________ metamorphic rocks are rocks whose pore space has been condensed by lithostatic pressure, but no layering. (ex. Quartzite and Marble)
Where do we find metamorphic rocks?
- Most are buried deep in the basement of the continents
- They are only exposed at the surface by uplift and erosion.
- Glacial scouring is also responsible for exposing large blocks of metamorphic rocks in the shield of the continents.
___________ is the unifying theory of Geology. Considerable geologic, paleontologic, and climatologic evidence is used to support the theory.
Earth's three main layers are the Crust (composed of continental and oceanic crust) the Mantle, and the Core. You can divide these layers based on other properties such as density, temperature, solidity:
a) __________- crust and upper mantle
b) __________- weak layer, heat softened
c) __________- middle layer
- Outer core
- Inner core
A ________ ______ is composed of the crust and the upper part of the mantle-also known as the lithosphere. It can contain both continental crust and oceanic crust. These plates move in a relationship to each other over the heat softened layer- the ___________.
- tectonic plate
The Earth has two poles (N & S). The poles create a _______ _____ in which electrons in magnetic substances such as iron align according to their ________ from the poles.
a. Magnetic force is weakest at the _________ and strongest towards the poles.
- magnetic field
Early maps of South America and Africa led people to speculate that the continents may have been joined together and split. The supercontinent was named:
In 1915, ________ ___________ wrote of a single supercontinent named __________, meaning "________". Wegener had no driving mechanism to explain his "continential drift" theory.
- Alfred Wegener
- all land
______________- the continents fit together very well, particularly when you include the continental margins.
________ ___ ____ __________ - marine, non-marine, and glacial rock sequences of Pennslyvanian to Jurassic age are nearly the same for all Gondwana continents, sugguesting they were joined at one time.
Similarity of Rock Sequences
Trends of several major ____________ ______ on separate continents match when the continents are repositioned
________ __________- striations and glacial deposits of the same age in the five southern continents
_______ __________- how could species evolve separately on different continents. Some of the most compelling evidence for continental drift comes from the ______ _____.
- Fossil evidence
- fossil record
The Earth's surface is covered by a series of __________________. The ocean floors are continually moving, spreading from the center and sinking at the edges and being regenerated.
_____________ boundaries are spreading centers that occur where plates are seperating. The crust is thinned, extended, and fractured as magma rises to the surface. The magma is almost entirely ____________ and intrudes into vertical fractures to form dikes and pillow lava flows. As lava cools, it record the intensity and orientation of the Earth's _______________.
a. RIFT valley (on land)
b. MOR/Ridge (in the ocean)
- magnetic field
Can you explain Continental Rifting?
a. During the early stages of continental breakup, magma wells up beneath large land masses.
b. The continental crust is elevated, stretched, and thinned which produces fractures, faults, rift valleys and volcanic activity
c. Evenually volcanic flows cover the valley floor (such as Iceland and eastern Africa)
d. If rifting continues, the continental crust ________________.
e. The more dense basaltic material subsides and form a narrow linear sea.
Most transform boundaries are in __________ crust, although one of the best known boundaries is the San Andreas Fault in California.
___________ are interplate features that are stationary.
a. A plume of __________ comes from deep in the mantle and forms a __________.
b. As plates move across these hot spots, chains of volcanic __________ and __________ are formed. (ex Hawaii)
- Hot spots
- magma; volcano
- mountains; islands
The ________ Cycle describes the way in which land masses come together and fragment on a cycle spanning about 500 million years. Through the Earth's history, we have had _________________ form and then break apart on a fairly regular basis. The lates of these-__________, occured 250 million years ago.