Exam 1

What is a Hot Spot or intraplate volcanism? Explain how Hawaii exemplifies a Hot Spot?

activity within a tectonic plate (far away from the boundaries) Theres a mantle plume under the big island right now so they've formed over a lot of years

Can you classify pyroclastic materials by size and shape?

ash: fine particles lapilli: fragments block: angular pieces bomb:round-shaped (liked football)

What is a chemical elements atomic number and mass number?

atomic number: # of protons mass number= # of protons + # of neutrons

Why volcanoes erupt?

because of the pressure in the earth forcing the hot rock through a crack

What is an igneous rock?

cooling and solidification of molten rock inside or outside of the earth surface

Understand and be able to describe major 3 rock types and the cycle they form.

igneous, sedimentary, metamorphic rock cycle*

How do intrusive and extrusive rocks differ?

intrusive: formed beneath the surface extrusive: formed above the surface

Why do most earthquakes & volcanoes occur in the "Ring of Fire"?

major subjection zones

Factors affect violence of a volcanic eruption.

more silica more violent highly viscous lavas how easily gases escape from magma.... more gas pressure means more violent eruptions

What are the 4 most abundant chemical elements in the Earth's crust?

oxygen, Silicon, aluminum, iron *(owls sing at irony)*

What is Magma mixing?

two chemically distinct magmas may produce a composition -quite different from original magma

Match the minerals and rocks with the ores discussed in class.

(end of notes)

What is punctuated uniformitarianism?

(uniformitarianism + Catastrophism) -current geology -geological processes generally uniform (slow) but interrupted by catastrophic events (tornado, hurricane)

What are physical properties of mineral and can you define them?

- Color -Streak -Luster -Hardness -Crystal shape -Cleavage -specific gravity -other

How volcanoes can be described in terms of recent eruptive history?

-Active: erupted recently and going to erupt again soon -Dormant: isn't currently active or erupting, but geologists think that it's still capable of erupting -Extinct: scientist consider unlikely to erupt again, because the volcano no longer has a lava supply

What is the list of volcanism related disasters?

-Pyroclastic (solid) flows: destruction of property -gas: clous cause suffocation -Lahars (mudflows): volcanic debris mixed with rainwater, stream water, or melted snow and ice -Earthquakes: due to movement of magma underground -Tsunamis: tidal waves generated by underwater earthquakes

What is an atom and what are its major constituents?

-basic units of matter & smallest - the smallest unit of an element

What is Magma differentiation?

-dark silicates precipitate first (olivine, pyroxene) -Light silicates precipitate later (quartz, feldspars, mica)

What is the silica tetrahedron?

-fundamental building block -4 oxygen ions surrounding a much smaller silicon ion

What is the definition of a mineral (5 characteristics of a mineral)?

-naturally occurring -inorganic -solid -characteristic crystalline structure -definite chemical composition

What are the 3 basic states of matter? What are controlling factors of those states?

Basic States: solid, liquid, gas Controlling: temperature, pressure

Which gas is the most dangerous? Why?

Carbon dioxide because....

What is the difference between Catastrophism and Uniformitarianism?

Catastrophism: -Dominant during the 17th and 18th century (traditional) -Features such as mountains and canyons were produced by sudden worldwide disasters (Genesis, Great flood of Noah) Uniformitarianism: -James Hutton considered father of geology by analyzing features of present to figure out past -"the present is the key to the past" -geological processes occurs over very long spans of time

What is Magma assimilation?

Changing a magmas composition by the incorporation of surrounding rock bodies into a magma

Contrast and understand the 3 different types of volcanoes.

Cinder Cone: -built from ejected fragments (pyroclastics) -steep slope angle -low heights -Felsic -Explosive -very common Shield: -broad,slightly domed -basaltic lava -generally large size -relatively quiet -Mafic -Low Gas (hawaiin islands) Composite: -stratovolcano -large size -steep slope angle -Lave & Pyroclastics -Intermediate (andesite) -most dangerous -Fuji in JP or Mt St Helens

What is the difference between cleavage and fracture of minerals?

Cleavage: break along planes of weakness pattern to split Fracture: No pattern

Can you identify difference between crater and caldera?

Crater: pit at opening created primarily by explosive excavation of rock during eruptions Caldera: large summit depression produced by collapse following a massive eruption

Dikes and Sills are small planar intrusive bodies; how do they differ?

Dike: pushes its way across layers of sediments Sill: pushes its way between layers of sediments

What is Geology and what does a Geologist do?

Geology is the science that pursues an understanding of planet earth. Geologist: -find and manage natural resources -study and teach about natural hazards -examine how earth works -discover earth history -study and teach about natural environments (anything related to earth & environment)

What is a scientific hypothesis and how does it differ from a scientific theory and scientific law?

Hypothesis: A tentative (or untested) explanation Theory: The hypothesis now withstands rigor of all the testing and consistently explains accumulating data Scientific Law: If a theory meets rigorous testing over a long period of time

Recognize other intrusive features.

Laccolith:similiar to sill, lens or mushroom shaped mass Batholith: largest intrusive body, surface exposure of a lot

How does magma differ from lava?

Magma: molten rock beneath the surface forms intrusive igneous rocks (plutonic) Lava: molten rock that has reached the surface forms extrusive igneous rocks (volcanic)

What is ore mineral?

Minerals of economic value

Two lava types (pahoehoe, Aa: describe each)

Pahoehoe lava: fluid basaltic lava having smooth ropy surface, low gas bubble Aa Lava: viscous basaltic lava w/ broken blocky surface (high gas bubble) pain very sharp when you walk on it

What is difference between physical and historical geology?

Physical geology: study of earth's features and how they were formed (e.g. rock cycle, erosion) Historical Geology: study of how the earth's geologic features and the evolution of life change through a time

What is viscosity? What factors affect magma viscosity?

Viscosity is the resistance to flow. -high Silica= high viscosity low silica= low viscosity -cooler temp= higher viscosity higher temp= lower viscosity -water and gas content= lower viscosity

Obsidian is a fascinating type of igneous rock. How does it form?

Volcanic: cool too quickly conchoidal fracture

What is the scientific method?

Way to ask and answer questions by making observations and doing experiments

What is the Moh's Hardness Scale?

1-10 hardest is 10 (diamond) and softest is 1 (Talc)

What are steps in the scientific method?

1. Observations 2. Questions 3. Hypothesis 4. Experiment 5. Conclusion

What kinds of gases are from volcanic eruption?

1. Water vapor (H20) 2. carbon Dioxide (CO2) 3. Sulfure (SO2) 4. Nitrogen (N) 5. Hydrogen, Chlorine