Page 1 of 83
EOSC 110 Midterm EXAM LATEST VERSION
2026-2027 ALL 180 QUESTIONS AND
DETAILED SOLUTIONS
Question: List the 3 types of metamorphism - CORRECT ANSWER✔✔1. Contact metamorphism,
2. Regional metamorphism, 3. Dynamic metamorphism
Question: Describe the 3 types of metamorphism and where they occur tectonically - CORRECT
ANSWER✔✔Contact metamorphism: Magma heats the surrounding rock. High temperature +
low pressure (<5km) = metamorphism with NON-FOLIATED ROCKS
Regional metamorphism: mountain building, divergent zones, subduction zones. High
temperature + high pressure (>5km) = FOLIATED ROCKS
Dynamic metamorphism: The rocks grind against each other in fault zones, creates friction
(heat) and lots of pressure. Low temperature + high pressure = weirdness = FOLIATED & 'ground
up' rocks.
, Page 2 of 83
Question: Explain the concept (and scope) of geologic time (Deep time) - CORRECT
ANSWER✔✔Geologic time: the timeline of the Earth's history, spanning over 4.5 Ga (billion
years).
Question: Discuss various lines of evidence for the age of the Earth - CORRECT ANSWER✔✔We
came up with the age of the Earth from evidence from meteorites and the moon.
Question: Describe how the geologic time scale developed from both relative and absolute
dating - CORRECT ANSWER✔✔The geologic time scale was first built using relative dating to
place rock layers and fossils in the correct sequence from oldest to youngest. Later, absolute
dating, specifically radiometric dating, was used to determine the actual numerical age of those
layers, assigning millions or billions of years to the timeline.
Question: Explain how we age rocks using radioactive isotopes - CORRECT ANSWER✔✔by
measuring the ratio of unstable "parent" isotopes to stable "daughter"
isotopes (the products of decay) trapped within a mineral's crystal structure. Because each
radioactive isotope decays at a known, constant rate called its half-life, comparing the current
, Page 3 of 83
parent-daughter ratio to the initial (known) ratio allows scientists to calculate the absolute age
of the rock since it first cooled and solidified.
Q:What are the layers of the Earth and their basic properties? - CORRECT ANSWER✔✔The Earth
consists of the crust, mantle, outer core, and inner core, each differing in composition and
behavior.
Question: What components make up the lithosphere? - CORRECT ANSWER✔✔The
lithosphere includes the crust and the uppermost part of the mantle.
Question: What early evidence supported the theory of plate tectonics? (Wegner's Continental
Drift Hypothesis) - CORRECT ANSWER✔✔Wegner proposes "Pangea" super continent.
He was able to use evidence of:
- Continent edges matching
- Fossil distribution
- Similar rock layers and mountain ranges appear on different continents
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- Glaciers were found in places that are now tropical
Question: Why was Wegener's Hypothesis of Continental Drift rejected? - CORRECT
ANSWER✔✔It lacked a mechanism to explain how continents could move, leading to skepticism
among scientists.
Question: What are the seven types of plate boundaries? - CORRECT ANSWER✔✔Divergent (2
types), Convergent (3 types), Transform (1 type), and Passive (1 type).
Question: What are the driving forces of Plate Tectonics? (describe mantle convection, slab
pull, and ridge push) - CORRECT ANSWER✔✔1. Mantle convection: heat currents can move 2
plates apart
2. Slab pull: at subduction zones, the denser plate pulls the rest of the plate down with it
3. Ridge push: at mid-ocean ridges, new hot rock rises and makes the plates slide away from
each other.
EOSC 110 Midterm EXAM LATEST VERSION
2026-2027 ALL 180 QUESTIONS AND
DETAILED SOLUTIONS
Question: List the 3 types of metamorphism - CORRECT ANSWER✔✔1. Contact metamorphism,
2. Regional metamorphism, 3. Dynamic metamorphism
Question: Describe the 3 types of metamorphism and where they occur tectonically - CORRECT
ANSWER✔✔Contact metamorphism: Magma heats the surrounding rock. High temperature +
low pressure (<5km) = metamorphism with NON-FOLIATED ROCKS
Regional metamorphism: mountain building, divergent zones, subduction zones. High
temperature + high pressure (>5km) = FOLIATED ROCKS
Dynamic metamorphism: The rocks grind against each other in fault zones, creates friction
(heat) and lots of pressure. Low temperature + high pressure = weirdness = FOLIATED & 'ground
up' rocks.
, Page 2 of 83
Question: Explain the concept (and scope) of geologic time (Deep time) - CORRECT
ANSWER✔✔Geologic time: the timeline of the Earth's history, spanning over 4.5 Ga (billion
years).
Question: Discuss various lines of evidence for the age of the Earth - CORRECT ANSWER✔✔We
came up with the age of the Earth from evidence from meteorites and the moon.
Question: Describe how the geologic time scale developed from both relative and absolute
dating - CORRECT ANSWER✔✔The geologic time scale was first built using relative dating to
place rock layers and fossils in the correct sequence from oldest to youngest. Later, absolute
dating, specifically radiometric dating, was used to determine the actual numerical age of those
layers, assigning millions or billions of years to the timeline.
Question: Explain how we age rocks using radioactive isotopes - CORRECT ANSWER✔✔by
measuring the ratio of unstable "parent" isotopes to stable "daughter"
isotopes (the products of decay) trapped within a mineral's crystal structure. Because each
radioactive isotope decays at a known, constant rate called its half-life, comparing the current
, Page 3 of 83
parent-daughter ratio to the initial (known) ratio allows scientists to calculate the absolute age
of the rock since it first cooled and solidified.
Q:What are the layers of the Earth and their basic properties? - CORRECT ANSWER✔✔The Earth
consists of the crust, mantle, outer core, and inner core, each differing in composition and
behavior.
Question: What components make up the lithosphere? - CORRECT ANSWER✔✔The
lithosphere includes the crust and the uppermost part of the mantle.
Question: What early evidence supported the theory of plate tectonics? (Wegner's Continental
Drift Hypothesis) - CORRECT ANSWER✔✔Wegner proposes "Pangea" super continent.
He was able to use evidence of:
- Continent edges matching
- Fossil distribution
- Similar rock layers and mountain ranges appear on different continents
, Page 4 of 83
- Glaciers were found in places that are now tropical
Question: Why was Wegener's Hypothesis of Continental Drift rejected? - CORRECT
ANSWER✔✔It lacked a mechanism to explain how continents could move, leading to skepticism
among scientists.
Question: What are the seven types of plate boundaries? - CORRECT ANSWER✔✔Divergent (2
types), Convergent (3 types), Transform (1 type), and Passive (1 type).
Question: What are the driving forces of Plate Tectonics? (describe mantle convection, slab
pull, and ridge push) - CORRECT ANSWER✔✔1. Mantle convection: heat currents can move 2
plates apart
2. Slab pull: at subduction zones, the denser plate pulls the rest of the plate down with it
3. Ridge push: at mid-ocean ridges, new hot rock rises and makes the plates slide away from
each other.
