Viewing All Flashcards for Geology
The study of all natural objects, processes, and phenomenon in the universe.
-Based on facts and observations from nature-NOT based on beliefs; beliefs and science dont mix-Make objective interpretations of all available evidence. -Goal: to predict events-Scientific ideas must be falsifiable (testable)
-Gather facts and observations-Explain how or why something works the way it does-Make a hypothesis (educated guess/rough ideas) about why it works the way it does-Test the hypothesis-Change the hypothesis if necessary-Repeat again and again-Theory: rigorously tested hypothesis or set of hypotheses
1) Continental Crust: thick, lightweight crust under landmasses.2) Oceanic Crust: thin, heavy crust under the seafloor.
The crust-mantle contact/boundary. Its short for Mohorovivcic Discontinuity
It is the crust and Moho and uppermost mantle. Crust and Lithosphere are NOT the same!2 types: Oceanic and Continental
Japan, Philippenes, Indonesia, Andes of South America, Aleutian Islands of Alaska, Cascade Range in Northern California, Oregan, Washington.
....break plates apart. ex) Yellowstone hotspot in Wyoming
From the cooling of hot, molten rock. (lava, magma)
Graphite, Diamond, Copper, Sulfur, Gold, Silver, Platinum, Arsenic, Antimony.
Crystalline, Clastic, Foliated, Glassy, and Vesicular/Frothy.
Hot molten rock deep underground.
Hot molten rock at/near land surface or on seafloor.
It is greater than or equal to 65% silica, its rich in K and Na, the dominant minerals are Quartz and K-Feldspar, and it is light colored.
It is about 45-52% silica, rich in Fe, Mg, Ca, it doesn't have ANY Quartz, the dominant minerals are Plagioclase Feldspar and Pyroxene.
At the land surface or on seafloor. It includes lava flows and ashbeds.
An intrusion of any size/shape.
A very large Pluton (>100km^2 in area), it can be any shape, but it is usually broadly bell-shaped. They are old, cooled, magma chambers. Ex) Sierra Nevada Batholith in California.
A planar intrusion that cuts across country rocks.
Conglomerates have rounded pebbles and are relatively common. Breccias have angular pebbles and are scarce.
Hypothesis: an educated guess/rough idea about why something works the way it does.Theory: a rigorously tested hypothesis or set of hypotheses. One small step below absolute certainty.
It is the study of the Earth. It involves the geosphere (rocks), hydrosphere (water), cryosphere (ice/glaciers), atmosphere, biosphere (life forms), pedosphere (soil), magnetosphere (magnetic field).
Mineralogy, paleontology, petrology, geomorphology, statigraphy, structural geology, and economic geology.
-helps us understand our planet and life on it-helps us understand natural disasteres-helps us find natural resources
Everything formed quickly in a big disaster. (1700s and before). Not still accepted.
Everything formed at slow, uniformed rates. All processes active now can explain features formed in the past. Proposed by Hutton and Lyell in late 1700s, early 1800s.
All processes now were active in the past, but with varying intensities.
-large central structure of Earth-Very hot, very dense-Not rock! Composed of metal; iron and impurities-core is composed of iron metal.-has 2 parts: inner core and outer coreinner core: solid iron. outer core: liquid iron.samples? controversial.
It surrounds the core.-very thick layer completely surrounding the core-mostly solid rock-realitively heavy rocks (peridotite)
-thin outtermost layer of the Earth-Two types: continental (thick, granite) and oceanic (thin, basalt)
1) 6370 km2) 33 km up to 75 km3) 7 km
Yes. You can touch mantle rocks and the Moho. ex) in Oman and Newfoundland and Cyprus
It is the #1 most important theory in all of geology
It was proposed by Alfred Wegener in 1918. It had an obvious match of the Americas to Africa and Europe. He also said the Atlantic ocean didn't exist 200 mil years ago. He said there was the supercontinent Pangaea. His evidence was the matching shorelines, similar fossils in areas now far apart, similar stratigraphies in areas now far apart. But he didn't know how the continents moved.
Pangaea was the supercontinent. No, it wasnt popular. Plate tetonics theory. 1960s to now.
Lithosphere rigid part of plates. it is the crust, Moho, and uppermost mantle. Two types, continental and oceanic.
The gooey layer of plates. its weak and its the entire remainder of the mantle below the lithosphere.
Pacific, Antartic, North American, Eurasia, South American, African, Inian-Australian, Nazca and Philippeans. PACFIC!
Heat currents in the mantle
At or near plate boundaries.
Divergence is 2 plates moving away from each other. where new oceanic crust is created. Seafloor spreading is on the seafloor.. Rpcks are young and hot NEAR, old and cool AWAY
2 plates moving toward each other. Crust is destroyed. 2 types: subduction -when one plate dives below another along a subduction szone. Collision- formation of mountain belts. (continental crust cant be subducted)
Himalayas (india converged with Asia), Alps of Europe (Africa with Europe), and Appalachians (Africa with N. America.)
2 plates sliding past each other. Crust isnt created or destroyed. San Andreas Fault
Hotspots. (mantle plumes) ex of hotspot: Eastern Africa and Afar hotspot
Modern age dating. Archbishop Usher estimated it by counting generations in the Bible.Buffon conducted cooling experiments ~ 75,000 yr old.Cuvier talked about Earth in terms of millions of yearsDarwin wrote book and estimated Earth to be 300 million years old.Kelvin used thermodynamics to estimate age ~ 98 to 24 mil. y old.John Joy used saltiness of oceans ~90 mil y old.
Modern age dating. from old solar system and earth. NOT FROM EARTH ROCKS! comes from oldest meteorites, mostlly from asteroid belt.
Newest record: 4.5 bil years old. New Record: 4.28 bil years oldtraditionally: 4.03 billion years old.
New rocks are forming all the time. Usuallly around volcanoes.
Archean, Proterozoic, Phanerozoic.
Precambrian, Paleozoic, Mesozoic, Cenozoic.
Cambrian, Ordovician, Silurian, Devonian, Carboniferous: Pennsylvanian & Mississippian, Permian, Triassic, Jurassic, Cretaceous, Tertiary, Quaternary
Paleocene, Eocene, Oligocene, Miocene, Pliocene, Pleistocene, Holocene.
2.5 by (oxygen levels began to rise)
251 my (worst extinction in history; trilobites)
65 my (dinosaur extinction)
Oxygen, Silicone, Aluminum, Iron, Calcium, Solium, Potassium, Magnesium. Oxygen and Silicone.
A solid orderly arrangement of atoms.
A naturally-occuring, solid, inorganic, crystalline substance having a fairly definite chemical composition and having fairly definite physical properties.Oil and Coal = NOT MINERALS! No.
Evaporation of water, cooling of hot, molten rock, intense alteration of previously existing minerals.
Crystal shape, cleavage, fracture, color, streak, hardness, luster, specific gravity, taste/feel/smell, double refraction, magnetism.
Cubic, agonal, double pyramid
The ability of a mineral to break along flat, planar surfaces. Ability of a mineral to NOT break along flat, planar surfaces. Smooth curved fracture surface.
The color of the minerals powder. Scratchablility; Mohs hardness scale/ scratch tests. Talc, diamond
Shininess. Metallic and Non-metallic
When light gets split in two by the molecular structure of the mineral. Calcite.
Elements: no anion, Oxides: one or more oxide anions, Carbonites: one or more Carbonate anions, Sulfides: one or more sulfide anions, Sulfates: one or more sulfate anions, Halides, Sillicates
Hematite, Magnetite, Corrundum
Calcite and Aragonite. Pyrite and Galena.
Quartz, Feldspar, Pyroxene and Amphibole, Mica
Potassium and Plagioclase
Flexibile, flakey. Muscovite (clear) and Biotite( blackish brown)
A more or less complex aggregate of minerals. 3 groups. By texture.
Igneous, sedimentary, metamorphic
Arrangement of crystals or grains in a rock. Crystalline: Closely interlocking crystals. Clastic: grains that were originally loose. Foliated: Crystals that are alligned more or less parallel. Glassy: No crystals at all. Visicular/Frothy: Rocks with holes that were originally gas bubbles in lava
Crystals that are too small to see with the naked eye. Crystals too small to see with normal microscopes; close to glassy but no shine.
Cooling of hot molten rock. Solidification of loose sediments. Intense alteration of previously existing rocks.
No. Igneous 65% of crust. Sedimentary 8% of crust.
Aphanitic: small crystals; cooled slowly. Phaneritc: large crystals;cooled quickly. Porphyritic: large & small crystals; slow, then fast cooling. Pegmatitic: HUGE crystals; very slow cooling/ cooling of a water rich magma.
Cooling of high viscosity lava. OR extremely rapid cooling
Explosive volcanic eruptions
B/c of cooling of lava rich in dissolved gases
Crystalline; phaneritic; intrusive
Crystalline, aphanitic, extrusive
Glassy; black; conchoidal fracture; very sharp edges; extrusive
Frothy; very light weight; usually floats in water; extrusive; light grey, tan, white colored
Extrusive; associated w/ subduction zones;
Intrusive; paneritic; crystalline; salt & pepper speckled appearance
Crystalline; aphanitic; extrusive; smaller crystals
Crystalline, phaneritic; intrusive
Frothy; lightweight; usually wont float in water; dark grey, dark brown, dark red; extrusive
Common in mantle; crystalline; phaneritic; intrusive; can be all olivine or all pyroxene or both
Clastic; multi-colored jumbles of grains; mix of large & small grains; large grains are angular in shape; forms from explosive volcanic eruptions
From solidification of loose sediments. Clastic. silicate minerals - quartz, feldspar, mica, etc.
Mix of large and small grains; pebbles and sand in mud; rounded pebbles; relatively common
Mix of large and small grains; pebbles and sand or mud; angular pebbles; scarce
Composed of sand-sized grains (between 2 mm and 1/16 mm); feels really rough and gritty to the touch; #2 most common sed. rock; white, brown, red, grey colored; dominated by quartz
Grains sized 1/16 to 1/256 mm; black, grey, red, brown colored; feels slightly rough/gritty
Clay-sized grains; smaller than 1/256 mm; feels relatively smooth; black, grey, red, green colored; weathers into think flat pieces; #1 most common sedimentary rock