EXAM 4 Flashcards
Continental Crust is younger than Oceanic Crust true or false.
False. Older
Convection currents occur in the _____________________ and helps pushes plates around.
Middle Mantle
Continental drift was not widely accepted when it was first proposed because _______________________.
because Wegner could not explain how or why Earth’s continents move.
Features found at divergent boundaries include __________________________________________________.
rift valleys, mid-ocean ridges, fissure volcanoes, underwater mountain chains, and areas of frequent shallow earthquakes
The driving force of tectonic plates is related to convection currents in Earth’s _____________________________.
MANTLE
At a convergent plate boundary between an oceanic and continental crust what will occur?
Because continental crust is lighter than oceanic crust, oceanic crust will create a subduction zone.
oceanic crust will slide underneath the continental crust.
This often creates deep ocean trenches and volcanic mountains like the Andes mountains in Peru and the Cascades in Washington
Define Pangaea.
almost all continents were merged into a single supercontinent
Describe the asthenosphere.
This is the layer below the lithosphere. This layer is “ plastic –like”. Maleable, somewhat solid
The Earth’s core is made primarily of_________________________________________________
iron and has NickeL
Why is the inner core of the Earth solid?
It is solid because of the pressure from the outer core, mantle, and crust compressing it.
The San Andreas fault is a good representative of a __________________________
Transform Boundary
The Nazca Plate seafloor is to pushing into the South American plate. What is the result of this collision?
subduction zone, under a convergent boundary. ocean to continent
What features are formed as a result of continental-continental convergence?
the two plates meet and crumple up; forming mountains.
When the Indian plate moved northward towards the Eurasian plate, what was the result of that collision?
Himalaya Mountains
The theory of ________________________________ states that plates move around on the asthenosphere.
plate tectonics
Why does the planet Earth have geologic features as earthquakes, volcanoes and mountains?
plate tectonics
The Earth’s plates ride on the liquid-like mantle, why?
The lithosphere is less dense than the asthenosphere, so the lithosphere “ floats” on the asthenosphere.
What is the driving force behind plate tectonics?
convection currents from heat.
Continental -Continental Convergence is different than the other types of convergent boundaries. Why?
Since both plates are less dense than the material in the asthenosphere, no subduction occurs
Oceanic Crust is _____________dense than ____________________crust because oceanic crust is primarily composed
of ______________________.
less
continental
iron magnesium calcium
How do we know about the different layers of the Earth?
observations of seismic waves
What is the correct order for the structure of the interior of the Earth from the surface to the interior?
Crust, Mantle, Outer Core, Inner Core
Explain how igneous rocks are formed?
Formed underground by trapped, cooled magma
Formed above ground when volcanoes erupt and lava cools
The driving force of metamorphism is _________________ and ____________________.
heat; pressure
Examine the image below and answer the question: Is this an intrusive igneous rock or an extrusive igneous rock and
why?
circle rock with a lot of cracks some colored
Intrusive
Examine the image below, is this a foliated or non-foliated metamorphic rock and why?
Lots of layers like a cake
foliated
You find a rock with pieces of fossilized seashells in a sedimentary rock. What is the best explanation on how
the seashells got there?
The hard parts of animals, such as bones and shells, can become cemented together over time to make rock.
Plant remains squashed deep underground over millions of years make an organic sedimentary rock.
Write the correct explanation for the formation of the Florida Keys?
during the iceless ice age sea level was
higher during Pleistocene interglacial periods, southernmost Florida was under water, and remained warm enough
and protected enough from introduced clastics, to build carbonate rock. The fossilized reef that we know as the
upper Florida Keys formed during this time period. Coral reefs, oolitic shoals (made of spherical, egglike, calcium
carbonate ooid grains), and deposits of shells and bryozoans all contributed to Florida’s Pleistocene-age carbonate
formations.
Why does pumice and scoria tend to have air bubbles, and granite does not have air bubbles in its composition?
formed from volcanic lava that rapidly cools, trapping the gas bubbles that were dissolved in the magma, while granite forms deep underground where pressure prevents gas from escaping
How could a metamorphic rock turn into an igneous rock?
subjected to extreme heat, causing it to melt and form magma, which then cools and solidifies
Most caves are formed because they are made up of what kind of rock and why?
imestone rock because it is easily dissolved by slightly acidic rainwater, which over time can create cavities and passages within the rock,
Stalagmites are found_________________________ in a cave.
Stalagmites rise up from the ground
Water seeping through the rock picks up the calcium carbonate and slowly build over time
The size of the crystals that form in slowly cooling magma tend to be ________________________
large
Lava cools quickly thus, tends to form _______________________________________ rocks
igneous
More and more sodium chloride is added to water until a rock begins to form (rock salt), what type of rock does
this represent?
Halite/ chemical sedimentary rock
Lava can only form which type of rock?
igneous
Clastic Sedimentary rocks are made from _________________________
weathering processes
Molten material deep inside Earth that igneous rocks form from is called___________________________.
Magma
Sandstone is mostly likely formed into a sedimentary rock through what process?
compaction and cementation
Shale is a sedimentary rock, under the forces of heat and pressure, shale most likely becomes _______________.
Slate/metamorphic rock
Foliated metamorphic rocks are distinguished by __________________.
visible banded or layered texture (birthday cake)
Magma that cools slowly forms _________________________ rock
(intrusive) igneous
The minerals mica, hornblende, feldspar, and quartz mix together to form this igneous rock_____________.
granite
Why will marble react with acid?
composed of calcium carbonate (CaCO3), which readily reacts with acids to produce carbon dioxide gas, water, and a calcium salt; essentially, when an acid comes in contact with calcium carbonate, a chemical reaction occurs causing the marble to fizz and dissolve slightly.
Why is Quartzite composed mostly of quartz?
formed from quartz-rich sedimentary rocks like sandstone under high-pressure and high-temperature conditions
nonfoliated metamorphic rock
If a metamorphic rock is subjected to too much heat and melts, will it still be a metamorphic rock and why or why not?
no because if the rock melts it becomes magma
When forming a sedimentary rock, if the grains are too big for the rock to form, how does a sedimentary rock
form?
the spaces between them are filled with dissolved minerals that precipitate out of solution, acting as a “cement” to bind the large grains together
Why is the state of Florida the nation’s number 1 place to find sinkholes?
Because FL is composed primarily of limestone, a highly soluble rock in a very wet climate
Metamorphic Rocks are formed from _________________
heat and pressure
If granite is subjected to heat and pressure, it will form into which type of rock?
gneiss (metamorphic rock)
According to the rock cycle, what is the correct order for the formation of a sedimentary rock
1- Cementation or Compaction
2- Weathering and Erosion
3- Sedimentary Rock
4- Sediments
- weathering
- sediments
- cementation
- sedi. rocks
How were the caves in Mariana Florida were formed?
While the area was covered in the sea, calcium carbonate was readily being deposited by marine organisms . Over the course of many years, the limestone breached the surface and the limestone started to get eroded by carbonic acid in the rainwater and groundwater, forming the caves and the famous cave features
Explain the difference between intrusive and extrusive igneous rocks?
Intrusive- when magma cools inside the earths surface
Extrusive- magma outside the earths surface
What is the chemical formula for Calcite?
CaCO3
What is the chemical formula for Carbonic Acid?
H2CO3
Here in the state of Florida, most of the minerals that we get here are formed from ____________________________.
marine deposits/limestone
Due to the properties of an Opal, an Opal is considered to be a _____________________.
mineraloid
Would an iceberg be classified as a mineral, why or why not?
yes. it is naturally occurring, solid ice (H2O), with a definite chemical composition and crystalline structure, which are the key criteria
What are the two different geological processes are minerals formed from?
from stuff dissolved in liquids
from cooling of magma
Why are silicates the most common minerals in rock forming compounds?
oxygen and silicon, abundant elements in the Earth’s crust, making them readily available to form minerals
What are the two most abundant elements in earth’s crust?
oxygen and silicon
What does the streak test tell you about a mineral and what are the limitations to the streak test?
streak is a more reliable property than color because streak does not vary.
it only works on minerals softer than the porcelain streak plate, meaning harder minerals will not leave a visible streak
What is lust and what the two divisions of luster and give an example of a mineral that displays that type of
luster.
metallic and nonmetallic. Luster is the appearance of reflection of light of a minerals surface
pyrite=metalllic
quartz=nonmetallic
When hydrochloric acid is applied to certain minerals, a chemical reaction occurs that produces carbon dioxide and water.
What mineral would this reaction occur?
calcite
Which is the correct chain of events to the formation of a rock?
- weathering
- sediments
- cementation
- sedi. rocks
Molten material beneath the earth’s surface is:
magma
Molten material on the earth’s surface is:
lava
Why is Pyrite a good example on why you should perform a streak test?
despite appearing visually similar to gold with its brassy yellow color, it produces a black streak when scratched against a ceramic plate, clearly distinguishing it from gold which would leave a golden streak
Minerals that cool quickly tend to have ___________crystals because ________________
small
little time to grow
List off of the characteristics that a mineral must pass to be a mineral?
Naturally occurring
Inorganic
Solid
Ordered internal molecular structure
Definite chemical composition
Which two physical properties of graphite make it a good mineral for use in pencils?
softness and ability to leave marks on paper easily
Which is the hardest mineral?
diamond
What is the softest mineral
talc
What are the major mineral groups?
Silicates, oxides, sulfates, sulfides, carbonates, native elements, and halides
A metal and an oxygen are classified as a
oxide
The most common mineral group are the ..
silicates
Which mineral bubbles when it comes in contact with hydrochloric acid?
Calcite
Label the crystalline shapes below, list some minerals that have those crystalline shapes.
see phone photos
