Geologic Mapping C

[UTF-8 U+6211 U+662F]

1. What is the difference between a normal and reverse fault?
2. What forces cause each type of fault listed above?
3. What is the difference between a reverse and thrust fault?

Click to Show Answer

1. Normal - Footwall up, Reverse - Footwall down

2. Normal - Tensional, Reverse - Compressional

3. Reverse - Dip over 45 degrees, Thrust - Dip less than 45 degrees

[OrigamiPlanet]

1. What is the difference between a normal and reverse fault?
2. What forces cause each type of fault listed above?
3. What is the difference between a reverse and thrust fault?

Click to Show Answer

1. Normal - Footwall up, Reverse - Footwall down

2. Normal - Tensional, Reverse - Compressional

3. Reverse - Dip over 45 degrees, Thrust - Dip less than 45 degrees

Perfect! Your turn!

[UTF-8 U+6211 U+662F]

Measuring a fold, you find an apparent dip of 5 degrees, but you later find that the axis of your measured dip is 32 degrees from the axis of the true dip. What is the true dip of the fold?

[hippo9]

fine

Answer (Click to Show Hidden Text)

5.9 degrees

[UTF-8 U+6211 U+662F]

fine

Answer (Click to Show Hidden Text)

5.9 degrees

Your turn.

[hippo9]

1. Subduction zones occur at what type of plate boundary?

2. What type of crust is "subducted" during subduction?

[UTF-8 U+6211 U+662F]

1. Subduction zones occur at what type of plate boundary?

2. What type of crust is "subducted" during subduction?

Click to Show Answer

1) Convergent (oceanic-continental or oceanic-oceanic)

2) Oceanic

[hippo9]

Click to Show Answer

1) Convergent (oceanic-continental or oceanic-oceanic)

2) Oceanic

Yep your turn

[UTF-8 U+6211 U+662F]

Suppose there are three drills going through a layer of rock underground. Assume all of the drills start at the same elevation. The first drill is pointed straight down and hits the layer at 1.1 km along its path. The second drill is 83 km north and 3 km east of the first drill. It is also pointed straight down. It hits the layer at 2.4 km along its path. The third drill is 75 km west of the first drill. It is angled at 85 degrees below horizontal pointing towards east and hits the layer at 1.9 km along its path. Find the strike and dip of the layer.

Bonus: If the first drill exits the layer at 1.2 km directly under it, what is the thickness of the layer?

[Reeeee-o-mapping]

I did this problem by drawing it out as opposed to just doing the math so my answer might be off.
Strike: N57°E, Dip: 11.2°NW, Thickness: 1.18 km