Can someone please answer SECTION D, where it asks about how many millions of ye
ID: 152539 • Letter: C
Question
Can someone please answer SECTION D, where it asks about how many millions of years ago North America and Africa were together
A. The map below shows the ages of seafloor basalt (the actual floor of the ocean, beneath the modern mud and sand) between North America and Africa. 1. Draw a red line on the map to show the exact location of the divergent plate boundary between the North American Plate and the African and Eurasian Plates. Refer to FIGURE 2.5 for assistance as needed. 2. Draw two blue lines on the map to show the exact position of two different transform fault plate boundaries. Refer to FIGURE 2.2 for assistance as needed. Holocene & Pliocene Miocene, Oligocene, Eocene, & North Spain Late 100 Lower 145 Africa Jurassic Kilometers 0 500 1000 1500 2000 B. Notice that points B and C were together 145 million years ago, but did the sea floor spread apart at exactly the same rate on both sides of the mid-ocean ridge? How can you tell? C. How far apart are points B and C today, in kilometers? 1. Calculate the average rate, in km per million years, that points B and C have moved apart over the past 145 million years. Show your 2. Convert your answer above from km per million years to mm per year D. REFLECT&DISCUSS Based on your answer in C1 above, how many millions of geologic period of time were Africa and North America part of the same continent? Show years ago and in what your work.Explanation / Answer
based on the answer in C1and also according to the picture and geological time scale as given here (right side of the picture) it is found that 215 million years ago and in early Jurassic time period (geological time period ) the Africa and North America were connected. that is they were part of the same continent
calculation procedure
step1
find out the rate of spreading of the plate . to do this use given timescale and distance scale.
let's measure the distance between the point A and B (according to given scale ) and then divide this distance by time (according to the time scale). it will be the rate of plate movement.( or one-way spreading )
step2
then measure the distance between D and A and then divide this distance by the one-way rate of spreading.
by doing this we get the requisite time, that is when both two together