SEDIMENTARY STRUCTURES AND ENVIRONMENTS by decree

VIEWS: 170 PAGES: 4

									SEDIMENTARY STRUCTURES AND ENVIRONMENTS
UW-GEOLOGY


1.    For each of the following sedimentary rocks, describe an environment (from the
      accompanying diagram) where they could be formed:




     a. sandstone with fossil shells   b. sandstone with grass fossils c. shale with fish fossils
     d. shale with worm burrows        e. conglomerate                 f. breccia
     g. skeletal limestone             h. chemical limestone
                                          QuickTime™ an d a
                                 TIFF (Uncompressed) decompressor
                                    are need ed to see this p icture.




                                              Figure 1

2.   What kind of sedimentary structure does figure 1 show?

3.   Describe a possible environment where this sedimentary rock could have formed.




                                          QuickTime™ and a
                                TIFF (Un compressed) decompressor
                                   are neede d to se e this picture.




                                              Figure 2

4.   What kind of sedimentary structure does figure 2 show?

5.   What does it tell about its paleo-environment?
                                            Figure 3

6.   What kind of sedimentary structure does figure 3 show?

7.   What does it tell about its paleo-environment?




                                            Figure 4

8.   What kind of sedimentary structure does figure 4 show?

9.   What does it tell about its paleo-environment?

10. Which way was the current flowing?
                                             Figure 5

11. Figure 5 was taken in the Great Rift Valley of Africa. The rock has been dated to be 50,000
    years old. Describe the paleo-environment conditions when this footprint was made.

12. A sedimentary rock tells about the environment in which it was deposited. Sometimes a
    layer-cake section (or “sequence”) of different sedimentary rocks can tell a story also.
    Research two sedimentary sequences – a transgressive sequence and a regressive
    sequence.
    a) Provide a definition (in your own words) for each sequence.
    b) Using words and diagrams, show how both sequences could come to be formed.

13. Sedimentary rocks owe their existence to the vast amounts of water on earth that
    weathers, transports and shapes them. If one is interested in finding extra-terrestrial life,
    one should look for water, and thus one should look for sedimentary rocks. This logic has
    been applied to Mars every since “canals” on the Martian surface were first seen with
    powerful telescopes decades ago.
    a) Are there sedimentary rocks on Mars? If so, describe them.
    b) Has water been found on Mars? If so, where?
    c) Has life been found on Mars? If so, what kind?

								
To top