The Geoloegy of Iceland

THE GEOLOEGY OF ICELAND

Seafloor spreading is the result of tectonic movement of the earth’s plates. Seafloor spreading occurs when one plate shifts left and the other shifts right – separating “down the middle”. Down the middle new crust is formed always pushing outward to allow ever newer crust to form at the ridge. This creates rift valley, new oceans, and the increasing in size of the Atlantic Ocean.

The map at the left shows the Midatlantic ridge at the center (and the bottom) of the Atlantic Ocean.

The map at the right shows how that the ridge passes directly through the island of Iceland.

Which plate is moving east? ______

Which Plate is moving west? ______

Given the movement of the plates from the diagram at the right, what do you think the effect is on the island of Iceland? ______

The picture at the left shows where the heaviest areas of volcanic and seismic activity occur in Iceland.

What does seismic activity mean ? ______

The areas of greatest seismic activity run along “fault line”. On the picture at the left, the fault line are shown as squiggly straight lines. In comparing the this diagram to the diagram at the top right of this page, what could you guess is the relationship between the Midatlantic Ridge and the seismic activity which occurs on Iceland? ______

Interestingly the diagram at the left shows the locations of four of the major volcanoes on Iceland. In comparing all four diagrams of Iceland, why do you think the volcanoes are located where they are?

______

The diagram to the right also shows the fault lines of seismic activity. This diagram and the diagram at the bottom of this page both show the relative age of the Icelandic rock on either side of the Midatlantic Ridge.

Scientists have been able to determine that the age of the rocks closest to the center of Iceland (those rocks surrounded by the fault lines) is less than 10,000 years old. Similarly, they have determined that the age of the rocks next to this center region is somewhere less than 2,000,000 years old. And scientist have estimated that the age of the rocks at the outer 1/3 of the island (on the east coast and west coast) are somewhere between 2 million years old to 65 million years old.

Do these diagrams support or disprove the concept of seafloor spreading. Explain your reasoning. ______

Why is Iceland such a valuable place to study geologic activity? You answer should b written in a well formed paragraph of at least 5 sentences. Write your answer on a separate sheet of paper.