Sedimentary Rock Lab

Classwork

Name ______Block ______

Step I – Sketch

All sedimentary rocks come from sediments. Some sedimentary rocks are called clastic because they are made of rock fragments. These fragments can be as small as microscopic clay particles or as large as boulders. The type of rock that forms is the result of the sorting of sediments that occurs when sediments are eroded and deposited elsewhere.

Look at the diagram on page 127. Copy the diagram below. Be sure to include the following labels: conglomerate, sandstone, shale, sand/gravel, sand, silt/clay, an arrow to show the flow of the river, and an arrow to show the direction of sorting from largest particle size to smallest particle size. Classwork

Step II – Shake It Up!

Obtain a cylinder filled with water, sand, pebbles, and silt. 1. Make a prediction, what order will the sediments fall to the bottom of the cylinder? 1st-

Shake the cylinder by turning it gently upside down and then right side up. 2. Which sediment was the first to settle? Why?

Pebbles because they are heavier

3. Which sediment was the last to settle? Why? Sand because it is light

4. Imagine this cylinder was actually a moving stream, which sediment will stay suspended longer in the stream, floating along with the current? Sand

5. Continue to imagine the cylinder as a stream, which sediment will roll along the bottom of the river as the current moves it?

Pebbles

6. What will happen to the shape of these large pieces if the water continues to move them?

Rounded Classwork

7. What has to occur in order for sediments to settle out of a moving river? (hint: the sediments began to settle in the cylinder once we stopped shaking it)

River has to lose energy when it meets a larger body of water.

Step III – Read and Answer Chapter 6, Section 3

1. According to the sorting of sediments diagram, what types of sediments make up conglomerates? Sand and gravel

2. According to the sorting diagram, which sediments consist of the smallest particles? Silt/Clay

3. According to the sorting diagram, how would the texture of conglomerates compare to that of shales?

Conglomerates would be rough and shale would be smooth.

4. From where a stream runs into a lake and out to the middle of that lake, in what order would you most likely find the three basic types of clastic sedimentary rock?

When a stream loses energy, sediments are deposited. Gravel, pebbles & sand

5. What is cementation? When minerals fill the spaces between sand grains , pebbles or other rock particles, they bind the fragments together

6. What does it mean to say that the minerals precipitate? When minerals precipitate out of solution Chemical action – ions combining to form new minerals Classwork

7. What happens during evaporation? How do minerals form during this process?

A solution with dissolved minerals evaporates leaving behind the minerals.

8. How do organic limestones form? Certain organisms produce carbonate shells or other support structures such as coral. When the organisms die, their calcium rich remains pile up on the ocean floor and the sedimentary rock is formed from these deposits.

9. Which process formed the rock salt flat in the photograph on page 129?

Chemical process - evaporation

10.Which sedimentary rock has an organic form as well as a chemical form?

Limestone

Step IV – Identify

Fill in the chart using the rock samples and your book. If there is more than one blank, then you are looking for more than one sample. You should consider the following samples:

31, 32, 33, 37, 39, 40, 41, 42, 45, 48, 50, 51, 52, 54, 55, 56, 59, 63, 64, 68, 69

Sedimentary Rocks Clastic Chemical Organic Conglomerates - Rock salt – rock Coal – black, made Sand and round form of halite, from fossilized plant gravel cemented reddish to tan in material together, sediment color (formed from a.__69______Classwork size varied evaporation) a.__31______a.__63______b.__32______c.__33______Sandstones – Sand- Rock gypsum – rock Fossil limestone – sized grains form of gypsum, pieces of shells compacted and pink to tan on color, cemented together cemented together powered sugar a.__54______a.__39______appearance (formed b.__55______b.__41______from precipitation) c.__56______c.__42______a.__64______Shales and Dolomite – pink to Chalk – white, used claystone– clay- tan color, crystal to write on slate sized grains visible on surface a.__68______invisible to the (formed from naked eye evaporation) a.__45______a. __59______b.__48______c.__50______d.__51______Breccia – light-color, Chemical limestone Coquina – pieces of sand and irregular – light in color, very shells compacted pebble fragments dense together (very little a.__37______a. __52______other material) a. __40______