Lab: Identifying Sedimentary Rocks
Sedimentary rocks form when rock fragments or sediments harden into rocks. They can be divided into three categories; clastic, chemical and organic. Clastic rocks have had their fragments cemented together. Chemical sedimentary rocks form when minerals precipitate from a solution and solidify. Organic sedimentary rocks form from the remains of living things.
TABLE 1:
Complete the following chart using the specimens provided.
Sample # / Name / Colour / Description or distinguishing features.1.
2.
3.
4.
6.
7.
17.
25.
24.
32.
2. Using the specimens provided, place each sample in the appropriate space on your Table 2. Do not peek at the key!
Table 2:
Clastic / Organic / ChemicalShale / Fossiliferous Limestone / Rock Salt
Sandstone / Coal / Chemical limestone
Arkose / gypsum
Conglomerate
Coquina
3. When you feel you have correctly placed each sample in the appropriate box, open the key and check your placement. Go back and complete the name column in Table 1.
4. Which samples were the easiest to identify? What specific feature was unique to each sample you have identified as easy.
5. If a river fed by mountain runoff brings sediments into a lake and they form clastic rocks, which type of rock will be found nearest shore? Which type of rock will be found farthest from shore? Explain your answer.
6. Which type of rock will form in a lake that is located in an area with a hot climate? Explain your answer.
Key:
1. Coal
2. Chemical limestone
3. Sandstone
4. Shale
6. Conglomerate
7. Arkose
17. Coquina
25. Fossiliferous limestone
24. Gypsum
32. Rock salt
Table 2:
Clastic / Organic / ChemicalShale / Fossiliferous Limestone / Rock Salt
Sandstone / Coal / Chemical limestone
Arkose / gypsum
Conglomerate
Coquina