Plates I Activity 2: Magnetic Reversals and Sea Floor Striping Name: Date: Lab S
ID: 286291 • Letter: P
Question
Plates I Activity 2: Magnetic Reversals and Sea Floor Striping Name: Date: Lab Section: Figure 1 shows the ocean floor around a spreading ridge. On the map, rocks with reverse magnetic polarity are represented by white bands and those with normal polanity by gray bands. I N A. -my Tmy Fig. 1 Table 1. Magnetic Polarity Durations 1. On the map: a. Identify and label the features identified by A and B on the west side of the ridge. Duration of ) magnetic anomalies to the east of the ridge Ni anomaly anomaly (m)- 1.4 0.4 0.5 0.9 0.7 1.6 0.8 0.5 b. Along the top of the figure, label the normal (NMagnetic h, N, etc., with M dosest the ridge. c. Along the top of the figure, label the reverse (R) magnetic anomalies east of the ridge Rs, Rz, Rs, R2 etc., with Rs closest the ridge. d. Draw a magnetic north arrow on each anomaly east of the ridge. (Hint: Don't forget the difference in the meaning of north for normal and reverse anomalies.) Ra 1.5 e. Mark each anomaly (white or gray band) on the 0.9 east side of the ridge with the length of time it represents using the data from Table 2-1. 0.7 Page 1 of 3Explanation / Answer
Answer3(a): The estimated age of the oldest oceanic crust is about 200 million years old. It is located in the far western equitorial pacific, east of the Mariana Island arc.
Answer3(g): The north Atlantic ocean basin begin to opened up around 160 million years ago. When a large continent like Pangea breaks up, it does so along a jagged line of rifts. These rift's often start off as three armed structure.
Amswer3(k): The south Atlantic ocean begin to formed around 140 million years ago as Africa separated from south america & about the same time, India separated from Antarctica & Australia, forming the central Indian ocean.