midterm 6 Flashcards
Who was Alfred Wegener and what did he do?
German Meteorologist laid out hypothesis that the continents were once together and then split apart.
What is unique about the magnetic field of the ocean floor?
That the Earth’s magnetic field was reversed when the basalts were created. Magnetic field reversed its polarity an average of every half million years. Magnetic strength to be in stripes
Where are the youngest and oldest sections of the oceanic crust?
young near the ridges and older closer to the continents. Trenches have the oldest and the ridges have the youngest.
What plate boundaries don’t have volcanoes?
continental-continental
What are the major faults in Utah and California?
Wasatch Fault and San Andreas fault line.
Where will you most likely find earthquakes and volcanoes here on Earth?
continental-oceanic zones.
fault lines and zones.
What are the most common rocks in the oceanic crust?
basalt
How old is the Earth?
4.6 billion years
What is an unconformity?
a break or gap in the geologic record.
noticing that certain fossils are missing, or by the worn off edges of rock layers. tell rocks age
What are all the principles of relative time?
determination of the sequence in which event occurred, relative to each other
- Original horizontality
- Superposition
- Inclusions
- Crosscutting relationships
- Faunal succession
What are all the geologic eras and what types of animals lived in them?
Precambrian- single-celled organisms
Paleozoic, ancient- marine invertebrates (trilobites, sponges, coral, mollusks) Fish, reptiles
Mesozoic, middle-dinosaurs, emergence of birds, small mammals, and flowering plants
Cenzoic, recent- mammals
Where is the oceanic crust formed?
Mid-ocean ridge
What type of convergent plate boundary doesn’t have Volcanoes?
Continental-continental
What are the 3 types of convergent plate boundaries?
continental-continental
continental-oceanic
oceanic-oceanic
What is all the evidence for continental drift and plate tectonics?
Plants and animals correlated, climate data, puzzle pieces, magnetic reversals, seductions zones, mid-ocean floor
Oceanic-Oceanic
when two oceanic plates collide, one dives under the other sinking, process called subduction.
They form Volcanic Island Arcs. (chain of volcanoes.
Ocean-Continent
in collisions, the oceanic plate always subducts.
collisions can create mountain belts and volcanoes. Material that comes from it will never subduct again so it makes the land grow.
continent-continent
collisions the material is welded together, nothing sinks because not dense enough.
How is rock salt formed?
salty ocean or lake evaporating
Crystal system of Halite?
cubic
what does a magnet attract to, magnetite and hematite?
magnetite
What colors do magnetite and hematite streak?
hematite: red
magnetite: black
What are rock salt, magnetite, hematite, orthoclase feldspar, olivine, mica, pyrite, amphibole, pyroxene, galena, and calcite have in common?
they are minerals
what happens with Hydrochloric acid and tums(calcuim carbonate), baking soda (sodium bicarbonate)?
it fizzes
What do we get from galena?
lead, its heavy
What is gypsum used for?
drywall, wallboard, plaster, fertilizer, blackboard chalk
What happens when you scratch gypsum with your nail? hardness
Hardness 2, fingernail easily scratches gypsum
What happens when corundum and steel scratch together? hardness
Hardness 9, Corundum scratches the steel
What does granite, diorite, gabbro, and peridotite have in common? descriptive
they are intrusive igneous rocks
What does rhyolite, andesite, and basalt have in common? descriptive
they are extrusive igneous rocks
What type of igneous rock take millions of years to cool and grow large crystals?
intrusive igneous rocks
What does gabbro, basalt, and peridotite have in common?
They are mafic
What does granite and rhyolite have in common?
they are felsic
Start with sandstone, heat pressure, what you get?
Quartzite
Limestone, heat pressure, what you get?
Marble
Tool to identify limestone?
hydrochloric acid
Tool to identify magnetite?
magnets
Tool to identify uraninite?
geiger counter
T/F: Minerals are aggregates of rocks, that is minerals made out of rocks?
false
What kind of rock has a fossil?
sedimentary
if you melted rocks, what kind you have?
Igneous rocks
most common rock of oceanic crust
basalt
most common elements of continental crust?
silicon and oxygen
What are the most common minerals of granite?
Orthoclase feldspar, Quartz, Muscovite Mica, Biotite Mica, Amphibole
What are the most common minerals of peridotite?
Olivine and Pyroxene
