Assignment 3 ESC1000 Spring 2018 1. Which of the following atoms is an isotope of Potassium-40 (which has 19 protons and 21 neutrons)?

Assignment 3 ESC1000 Spring 2018

1. Which of the following atoms is an isotope of Potassium-40 (which has 19 protons and 21 neutrons)?

(1) an atom with 21 protons and 19 neutrons

(2) an atom with 20 protons and 20 neutrons

(3) an atom with 19 protons and 20 neutrons

(4) an atom with 40 protons and 40 neutrons

(5) an atom with 22 protons and 18 neutrons

2. What is the atomic mass of a Calcium atom that has 20 protons, 24 neutrons, and 20 electrons?

(1) 44

(2) 20

(3) 24

(4) 40

(5) 48

3. If a mineral has a daughter to parent ration of 7:1 (seven daughter atoms for every one parent atom), how many half-lives have passed since the mineral formed?

(1) 0

(2) 1

(3) 2

(4) 3

(5) 4

4. Refer to Figure 1 on the last page. The boundary L, between sandstone B and underlying rocks is called a(n):

(1) angular unconformity

(2) nonconformity

(3) disconformity

(4) isotopic unconformity

(5) baked contact

5. Refer to Figure 1 on the last page. The boundary O, between conglomerate L and underlying metamorphic rocks (M) is called a(n):

(1) angular unconformity

(2) nonconformity

(3) disconformity

(4) isotopic unconformity

(5) baked contact

6. Refer to Figure 1 on the last page. The boundary J, between the shale G and underlying sandstone B is called a(n):

(1) angular unconformity

(2) nonconformity

(3) disconformity

(4) isotopic unconformity

(5) baked contact

7. Refer to Figure 1 on the last page. Which of the following is true regarding the age dike H?

(1) it is younger than limestone A

(2) it is younger than sandstone B, but older than shale G

(3) it is Paleocene in age

(4) it is younger than sandstone F, but older than shale E

(5) it is older than dike/sill D

8. Refer to Figure 1 on the last page. Which of the following is true regarding the age of motion on fault N?

(1) it is younger than conglomerate I, but older than sandstone B

(2) it is younger than sandstone F, but older than sandstone B

(3) it is younger than dike D, but older than sandstone B

(4) it is younger than metamorphic rocks M, but older than conglomerate I

(5) it is younger than sandstone B, but older than shale G

9. Refer to Figure 1 on the last page. Which of the following is true regarding the age dike/sill D?

(1) it is younger than dike H

(2) it is younger than metamorphic rocks M, but older than shale E

(3) it is younger than metamorphic rocks M, but older than sandstone F

(4) it is Paleocene in age or younger

(5) it is younger than shale E and older than sandstone B

10. Refer to Figure 1 on the last page. Analysis of dike/sill D yielded 14,000 daughter atoms and 2,000 parent atoms. On the basis of this ratio, how many half-lives have passed since the mineral formed?

(1) 1

(2) 2

(3) 3

(4) 4

(5) 5

11. If the isotope from the previous question has a half-life of 25 million years, what is the age of dike/sill D?

(1) 3 million years

(2) 25 million years

(3) 50 million years

(4) 75 million years

(5) 100 million years

12. Refer to Figure 1 on the last page. Place the sequence of events in order from oldest (left) to youngest (right).

(1) M – N – O – I – F – E – C – P – L – D – B – J – G – H – A – K

(2) M – N – O – I – F – E – C – P – L – D – B – J – G – H – K – A

(3) D – M – N – O – I – F – E – C – P – L – B – J – G – A – H – K

(4) M -O – I – N – F – E – C – D – L – B – J – G – A – H – K

(5) M – N – O – I – F – E – C – D – P – L – B – J – G – A – H – K

(6) M – N – O – I – F – E – D – C – L – B – P – J – G – A – H – K

(7) M – N – O – I – F – E – D – C – H – P – L – B – J – G – A – K

(8) M – N – O – I – F – E – D – C – P – L – B – J – G – K – A – H

(9) O – I – M – N – F – E – C – D – P – L – B – J – G – A – H – K

(10) M – N – O – I – F – E – P – C – D – L – B – J – G – A – H – K

Figure 1

This list describes each feature, labeled with letters, in the vertical cross-section shown in Figure 1.

A. Deposition of Oligocene limestone

B. Deposition of Paleocene sandstone

C. Deposition of limestone

D. Intrusion of granite dike and sill (laccolith)

E. Deposition of shale

F. Deposition of sandstone

G. Deposition of Oligocene shale

H. Intrusion basalt dike

I. Deposition of conglomerate

J. Unconformity

K. Erosion to form valley

L. Unconformity

M. Folded & metamorphosis of rocks formed at depth

N. Fault

O. Unconformity

P. Tilting of rock layers (Note that this is not labeled in Figure 1)

Also, you will need to refer to the Geologic time scale Figure 9.16b on page 298 Remember the principles of original horizontality and cross-cutting relationships on page 285 Also, recall the types of unconformities on page 295