Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
44 Cards in this Set
- Front
- Back
Why is it important to understand history of Earth? |
1. origin/ev. of life 2. formation of natural res. 3. effects of geologic hazards 4. cc 5. ev. of other planets |
|
What is a hypothesis? |
Statement designed to explain set of ob.; able to predict ob., must be FALSIBLE; good hypothesis explains ALL existing ob. |
|
What are the two definitions of science? |
1. body of knowledge related to the study of natural phenomenon 2. application of scientific method--gather facts, form hypothesis, eval. hypotheses (test) |
|
What's a theory? |
Well tested, widely accepted hypothesis; explain observational facts; all theories are provisional |
|
What is the nebular hypothesis? |
Rotating cloud called the solar nebula made of hydrogen/helium began to contract 5mya,_________________ |
|
What is chemical differentiation? |
Creates layered Earth, lighter on outside, denser inside |
|
Name the COMPOSITIONAL layers of Earth from inside to out. Then name mechanical layers inside to out. |
Core, crust, mantle; mechanical = Inner/outer core, lower mantle, asthenosphere, lithosphere |
|
Define catastrophism and uniformitarianism. |
Cat--earth's landscapes were shaped primarily by catastrophes; Unif--the physical, chemical and biologic laws that operate today have operated in the geo. past |
|
Under stand the rock cycle. |
See chart. |
|
Plate tectonics is concerned with motion of what layer of Earth? |
Lithosphere |
|
Describe relative motion, topography, volcanic activity, and earthquake depth of a DIVERGENT boundary. |
Plates separate, new seafloor made; |
|
Describe relative motion, topography, volcanic activity, and earthquake depth of a CONVERGENT boundary.
|
plates collide, subduction of oceanic plate into mantle; volcanic arcs, |
|
Describe relative motion, topography, volcanic activity, and earthquake depth of a TRANSFORM boundary.
|
slide past each other; |
|
List and describe forces driving plate motion. |
Slab pull: convergent Ridge push: divergent Mantle convection: plates move in circular motion |
|
The characteristics of a mineral include: |
1. Naturally occurring 2. Inorganic solid 3. Ordered internal mol. structure 4. Definite chemical comp. |
|
Name the 3 forces that are the sources of Earth's heat. |
Collisions, compression, radioactivity |
|
Name the three kinds of chemical bonds. |
1. Ionic = Atoms gain/lose electrons to form ions; orderly arrangement with oppositely charged ions 2. Covalent = SHARE electrons, stronger than ionic; happens in same as ionic though 3. Metallic = valence elec. free to migrate among atoms; weaker and less common |
|
What do the atomic #, atomic mass, and isotopes tell you? |
Mass = number of protons and neutrons Number = numbers of protons Isotopes = same element with different mass, same atomic number |
|
List the physical prop of minerals |
Crystal form Luster Color Streak Hardness Fracture Spec. Gravity |
|
What two elements are most abundant in continental crust? |
Oxygen and silicon |
|
Silicate structures |
_________________ |
|
Igneous rocks can be ____ and ____. |
Extrusive; cooled at or near surface Intrusive; cooled beneath surface |
|
What is the steep part of the geothermal gradient representative of? What do the curves mean? |
Convection in the mantle; curves are explained by conduction |
|
How is magma generated? |
1. Heating rocks above melting point 2.Lowering melting point by decreasing pressure OR adding volatiles |
|
What does magma contain? |
Molten rock that has suspended crystals and dissolved gases such as water vapor, CO2 and sulfur dioxide |
|
What is assimilation? |
Changing of a magma's composition by incorporating surrounding rocks bodies |
|
Magma Mixing is? |
combining two compositionally distinct magma |
|
Describe the discontinuous reaction series. |
Olivine to pyroxene to amphibole to biotite |
|
Describe the CONTINUOUS reaction series. |
Ca-Rich Plagioclase to Na-Rich Plagioclase |
|
What factors control the texture of igneous rocks? |
Rate of Cooling = slow is large, fast is small crystals Amount of Silica = Amount of dissolved glasses = |
|
What are the three textures of igneous rocks. |
1. aphanitic (ex. Rhyolite) very small crystals; fine grained 2. phaneritic; crystals can be seen; coarse grained (Granite) 3. porphyritic; large crystals in a finer grained matrix (looked mixed) 4. Glassy; lacks crystals because of rapid cooling (Obsidian) 5. Vesicular; many elliptical cavities formed by gas bubbles in rock (Pumice) |
|
Concordant is ? |
Sills, laccoliths; runs parallel to pre-existing rock |
|
Discordant is ? |
Dikes, batholith; cuts across pre-existing rock |
|
Where can volcanic/plutonic activity occur? |
1. Hotspots (Hawaii, yellowstone) 2. Convergent margins within volcanic arc (South American Andes) 3. Divergent margins at mid-ocean ridge |
|
What determines viscosity of magma? |
1. Temp of magma 2. Composition of magma 3. Dissolved gases in magma In turn this controls nature of an eruption |
|
What factors effect viscosity? |
1. Composition - SiO2 content 2. Temp 3. Amount of dissolved gases |
|
Name and describe the 2 kinds of basaltic lava flows. |
1. Pahoehoe flows; have smooth surfaces and resemble twist braids of rope 2. Ah-ah flows; have surfaces of rough jagged rocks |
|
List the kinds of magma in order from least to most gas content. |
Basaltic magma, andesitic magma, rhyolitic magma |
|
What's ash fall? |
fragments ejected into air during eruption; dust-size fragments to meters in diameter |
|
What are pyroclastic flows? |
swiftly moving, turbulent flow composed of gas and rock fragments |
|
Describe pumice and scorria. |
Pumice; light gray or pink porous rock from frothy andesitic rhyolitic lava Scorria; red-brown porous rock from frothy basaltic and andesitic lava |
|
What are the 3 types of volcanoes? Describe. |
Shield; broad and short; produced by mild eruptions of large volumes of basaltic lava Cinder Cone; steep slope, occur in groups, made from ejected lava fragments Composite; classic, large volcanoes |
|
What is a caldera and how does it form? |
A crater larger than 1km in diameter, form by collapse following an explosive eruption |
|
Describe the 3 kinds of magma. |
Basaltic/Mafic; least silica, least gas, least viscosity (shield vol., basalt plateaus, cinder cones) Andesitic/Intermediate; some silica, kind of viscous, some gas (composite cones) Felsic/Granitic; most silica, most gas, most viscous (volcanic domes, pyroclastic flows) |