Read topographic and geologic maps

Grade 9 Science Worksheet - Challenge Me

Circle the best answer.

1. 1.

   Close contour lines mean the rock is hard and resists erosion. A classmate says close contours mean the rock is hard and resists erosion. Ari replies. Which reply is strongest?

   • Yes: close lines are drawn only where the rock is the oldest
   • Yes: steep ground forms in hard rock, and that is shown by close lines
   • No: close lines show steep ground only; rock type needs a geologic map
   • No: close lines show flat ground, so the rock must be soft

2. Read this first

   Claim

   On a profile with vertical exaggeration 5, a hillside looks like a slope of 1.0, about 45 degrees. A friend says the real hillside is 45 degrees.

3. 2.

   A profile has vertical exaggeration 5. A hillside looks 45 degrees. Bo's friend says the real hillside is 45 degrees. Which reply fits?

   • No: the real slope is about 5, since the profile flattens it
   • Yes: a profile shows the true slope of the ground
   • No: the real slope is about 0.2, near 11 degrees, since 1.0 ÷ 5
   • Yes: 45 degrees is the usual slope of a hillside

4. Use this

   Geologic map G (made up). Legend, youngest to oldest: Qal, alluvium (Quaternary, yellow); Ks, sandstone (Cretaceous, olive); Jm, mudstone (Jurassic, green); Pl, limestone (Permian, blue); Xg, gneiss (Precambrian, gray). Xg lies in the southwest. Pl lies north of Xg and rests on it. Jm lies north of Pl, and Ks lies north of Jm. Dike d (diabase) cuts Xg and Pl and ends at the Jm contact. Alluvium Qal fills the stream valley and covers the edge of Ks. Fault f cuts Pl, Jm and Ks but not Qal.

5. 3.

   A classmate says dike d on map G is the youngest feature, since it cuts two units. Esme checks the map. Which reply is strongest?

   • No: Xg is younger than d, since Xg is gray and d is darker
   • Yes: a dike that cuts two units is younger than the other units
   • Yes: dikes are igneous, and igneous rocks form last
   • No: d ends at the Jm contact, so Jm, Ks, f and Qal are younger

6. Card

   Map scale 1:50,000, so 1 cm is 50,000 cm on the ground. Two points 4 cm apart are at 400 m and 600 m.

7. 4.

   Two points are 4 cm apart on a 1:50,000 map, at 400 m and 600 m. What average slope does Jun get?

   • 0.001, found as 200 m ÷ 200,000 cm
   • 10, found as 2,000 m ÷ 200 m
   • 0.1, found as 200 m ÷ 2,000 m
   • 0.05, found as 200 m ÷ 4,000 m

8. Card

   a stream reach drops 80 feet over 2.5 inches on a 1:24,000 map. 1 inch is 2,000 feet; 1 mile is 5,280 feet.

9. 5.

   A stream reach drops 80 ft over 2.5 inches on a 1:24,000 map. What gradient does Kira find, in feet per mile?

   • About 32 ft per mile, found as 80 ÷ 2.5
   • About 0.016 ft per mile, found without 5,280
   • About 7 ft per mile, found by using 24,000 ft per inch
   • About 84 ft per mile, found as 80 ÷ 5,000 × 5,280
10. 6.

    a cliff rises 600 feet over 1,500 feet of ground. The profile has vertical exaggeration 4. A cliff rises 600 ft over 1,500 ft on the ground. A profile has vertical exaggeration 4. What does Luz get for the true and apparent slope?

    • True 0.4; it looks like 1.6, four times steeper
    • True 0.4; it looks the same, 0.4, on the profile
    • True 1.6; it looks like 0.4 on the profile
    • True 0.1; it looks like 0.4 on the profile

11. Use this

    Geologic map G (made up). Legend, youngest to oldest: Qal, alluvium (Quaternary, yellow); Ks, sandstone (Cretaceous, olive); Jm, mudstone (Jurassic, green); Pl, limestone (Permian, blue); Xg, gneiss (Precambrian, gray). Xg lies in the southwest. Pl lies north of Xg and rests on it. Jm lies north of Pl, and Ks lies north of Jm. Dike d (diabase) cuts Xg and Pl and ends at the Jm contact. Alluvium Qal fills the stream valley and covers the edge of Ks. Fault f cuts Pl, Jm and Ks but not Qal.

12. 7.

    Noah claims dike d is older than Jm on map G. Which finding would most challenge that claim?

    • A place where d cuts Xg, as it does elsewhere
    • A note that d is drawn in a darker color than Pl
    • A place where Jm lies unbroken across the top of d
    • A place where dike d cuts across Jm mudstone
13. 8.

    Pia claims fault f is younger than Ks on map G. Which evidence on the map supports that claim most?

    • f cuts Ks, while Qal lies across f without a break
    • f cuts Pl, the oldest unit that it touches
    • f is a straight line, and straight lines are young
    • f lies north of Pl, which is Permian

14. Card

    Contours join equal elevations. The interval is the gap between neighboring lines. Close lines mean steep ground. V's in valleys point upstream. Contours do not show rock type.

15. 9.

    Ren writes one summary of contour lines. Which one fits best?

    • Lines of equal height; close lines are steep, and they show hard rock
    • Lines of equal slope; close lines are steep, valley V's point upstream
    • Lines of equal height; close lines are flat, valley V's point downstream
    • Lines of equal height; close lines are steep, valley V's point upstream

16. Card

    Ground distance = map distance × scale. Slope = rise ÷ run, with the same units. Feet per mile uses 5,280 feet. A stretched vertical scale makes slopes look steeper.

17. 10.

    Tala writes one summary of reading slope from a map. Which one fits best?

    • Rise ÷ map distance, then multiply by the scale and exaggeration
    • Scale to ground distance, then rise ÷ run, then divide by exaggeration
    • Scale to ground distance, then run ÷ rise, then multiply by exaggeration
    • Rise ÷ run on the map in any units, then ignore exaggeration