ESS 101 LAB - ADVANCED EARTH
SCIENCES QUESTIONS AND ANSWERS
WITH VERIFIED SOLUTIONS. JUST
RELEASED
1. In a topographic map, if the contour interval is 20 feet and there are four contour lines
between point A (on a labeled 400ft line) and point B, which is higher up a continuous slope,
what is the elevation of point B?
A. 480 feet
B. 500 feet
C. 460 feet
D. 520 feet
Answer: B
Conceptual Explanation: With four lines between the 400ft line and point B, point B is the
fifth line. 5 lines multiplied by 20 feet equals 100 feet. 400 + 100 = 500 feet.
,2. Which mineral group is characterized by a framework of silicate tetrahedra where every
oxygen atom is shared between two tetrahedra?
A. Inosilicates
B. Phyllosilicates
C. Cyclosilicates
D. Tectosilicates
Answer: D
Conceptual Explanation: Tectosilicates, such as quartz and feldspar, feature a 3D
framework where all oxygen atoms in the SiO4 tetrahedra are shared.
3. According to Bowen’s Reaction Series, which mineral is the first to crystallize from a cooling
mafic magma in the discontinuous branch?
A. Olivine
B. Biotite
C. Pyroxene
D. Quartz
Answer: A
Conceptual Explanation: Olivine is the highest-temperature mineral in the discontinuous
series and crystallizes first as magma cools.
, 4. If a radioactive isotope has a half-life of 700 million years and a rock sample contains 12.5%
of the parent isotope, how old is the rock?
A. 1.4 billion years
B. 2.8 billion years
C. 2.1 billion years
D. 3.5 billion years
Answer: C
Conceptual Explanation: 12.5% represents three half-lives (100% to 50% to 25% to
12.5%). 3 multiplied by 700 million equals 2.1 billion years.
5. Which metamorphic facies is associated with high-pressure but low-temperature
conditions, typically found in subduction zones?
A. Greenschist
B. Granulite
C. Blueschist
D. Zeolite
Answer: C
Conceptual Explanation: Blueschist facies form under high pressure and relatively low
temperatures, characteristic of the rapid burial of oceanic crust in subduction zones.
SCIENCES QUESTIONS AND ANSWERS
WITH VERIFIED SOLUTIONS. JUST
RELEASED
1. In a topographic map, if the contour interval is 20 feet and there are four contour lines
between point A (on a labeled 400ft line) and point B, which is higher up a continuous slope,
what is the elevation of point B?
A. 480 feet
B. 500 feet
C. 460 feet
D. 520 feet
Answer: B
Conceptual Explanation: With four lines between the 400ft line and point B, point B is the
fifth line. 5 lines multiplied by 20 feet equals 100 feet. 400 + 100 = 500 feet.
,2. Which mineral group is characterized by a framework of silicate tetrahedra where every
oxygen atom is shared between two tetrahedra?
A. Inosilicates
B. Phyllosilicates
C. Cyclosilicates
D. Tectosilicates
Answer: D
Conceptual Explanation: Tectosilicates, such as quartz and feldspar, feature a 3D
framework where all oxygen atoms in the SiO4 tetrahedra are shared.
3. According to Bowen’s Reaction Series, which mineral is the first to crystallize from a cooling
mafic magma in the discontinuous branch?
A. Olivine
B. Biotite
C. Pyroxene
D. Quartz
Answer: A
Conceptual Explanation: Olivine is the highest-temperature mineral in the discontinuous
series and crystallizes first as magma cools.
, 4. If a radioactive isotope has a half-life of 700 million years and a rock sample contains 12.5%
of the parent isotope, how old is the rock?
A. 1.4 billion years
B. 2.8 billion years
C. 2.1 billion years
D. 3.5 billion years
Answer: C
Conceptual Explanation: 12.5% represents three half-lives (100% to 50% to 25% to
12.5%). 3 multiplied by 700 million equals 2.1 billion years.
5. Which metamorphic facies is associated with high-pressure but low-temperature
conditions, typically found in subduction zones?
A. Greenschist
B. Granulite
C. Blueschist
D. Zeolite
Answer: C
Conceptual Explanation: Blueschist facies form under high pressure and relatively low
temperatures, characteristic of the rapid burial of oceanic crust in subduction zones.
