Geology Cafe

Introduction to Geology

Quiz 9 - Sedimentary Rocks

1. Sediments or sedimentary rocks composed of fragments derived from older rocks are called:
a) metamorphic.
b) clastic.
c) non-clastic.
d) shale.
e) all of the above.

2. A coarse-grained sandstone that contains at least 25 percent feldspar fragments is called:
a) mudstone.
b) conglomerate.
c) arkose.
d) graywacke.
e) all of the above.

3. Which of the following would be considered a clastic sedimentary rock?
a) shale
b) conglomerate
c) sandstone
d) mudstone
e) all of the above

4. What type of rock consists of angular rock fragments (cemented together) that may be sedimentary, volcanic, or tectonic fracturing origin?
a) breccia
b) conglomerate
c) sandstone
d) limestone
e) all of the above

5. Mud composed of skeletal and organic remains of microscopic organisms that accumulate on a lake bed or ocean floor is called:
a) chert.
b) shale.
c) soil.
d) ooze.
e) all of the above.

6. Organic matter, mostly plant material, that accumulates as sediment in boggy or swampy environmental settings is called:
a) peat.
b) shale
c) lime mud.
d) ooze.
e) none of the above.

7. Which is not a calcareous rock (composed mostly of the mineral calcite)?
a) limestone
b) travertine
c) coquina
d) chert
e) none of the above

8. Sediments settling out in a lake or ocean basin after an underwater landslide and associated turbidity current results in:
a) graded bedding.
b) cross bedding.
c) desiccation cracks.
d) lamination.
e) all of the above.

9. A rock formed by the replacement of calcite [ CaCO3 ] with the mineral dolomite [ Ca,Mg(CO3)2 ] is called:
a) limestone.
b) mudstone.
c) shale.
d) dolostone.
e) none of the above.

10. Stirring or mixing of sediment or soil by organisms, especially by burrowing, boring, crawling, feeding or other traces left by biological activity is called:
a) fossils.
b) bioturbation.
c) lithification.
d) deposition.
e) all of the above.

Extra Credit:

Common sedimentary features found in sandstone that are associated with migrating sand dunes includes:
a) fossils.
b) cross bedding.
c) desiccation cracks.
d) graded bedding.
e) all of the above.

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8/28/2012