Field Trip to Dungy Head and St

Field Trip to Dungy Head and St. Oswald’s Bay

Name ______

1. Scroll down to the Table of Contents and read the introduction (DH-1) to the area around Dungy Head and St. Oswald's Bay. Then go to DH-6, click on the geologic column showing the strata of the Lulworth Region and answer the following questions: A. What is the thickness of the Upper Cretaceous chalk with black flint?

B. What evidence is there for organic matter in the Wealdon Group marls?

C. What fossils are found in the Kimmeridge Clay?

2. Now go to DH-19, read the text beneath the two figures and then click on the first geological cross-section diagram of Lulworth Cove and answer the following questions: A. What kind of anticline is illustrated in this section?

B. What is the feature called that underlies the Chalk, Greensand and Gault? (Hint: look at

the first figure in DH-6)

C. Scroll down to DH-19a and read the text beneath the figure. What is an inversion

structure?

3. Dungy Head (DH-11) is a good location to see what strata? How thick is it?

4. What mineral that is also found on Mars is precipitating from the spring at St. Oswald’s Bay (DH-16a)?

5. At DH-17 find a description of the Gault Clay at St. Oswald's Bay and answer the following questions: A. Is it a marine or nonmarine deposit? On what evidence is your answer based?

B. Why is it called the "Blue Slipper" in the Isle of Wight?

C. Three kinds of clay minerals occur in the Gault, one of which is expandable. Which one

is it?

D. Is the upper contact with the greensand abrupt or transitional?

6. At DH-22 how can you test the direction of movement on the faults in the Upper Chalk? 7. At St. Oswald's Bay (DH-24) there are some striking examples of dolines. What are these features and how did they form?

8. At DH-27 the Lower Chalk at Man O'War Head consists of cyclical, alternating beds. What is the probable explanation for the origin of these cycles? A conspicuous marker bed in the chalk has a characteristic index fossil. What is it?

Well, that's enough for today. Besides, it is starting to rain and I notice a few of you forgot to bring rain gear (tsk, tsk).