Don Valley Brick Works: Part B: The Rock

Part B The Rock

Large amount of shale deposit(by BC)

1. Clay (http://www.traditionaloven.com
/articles/wp-content/
uploads/2008/06/fire_clay_in
_bag.jpg&imgrefurl)

2. Shale with Fossil Evidence(by BC)

3. Shale(by BC)

    1.The Differences between clay and shale.
          There are many kinds of rocks in the Don Valley Brick works. Shale is the most typical rock that can be found in the area. Shale is a fine grained sedimentary rock mainly made of clay, and some quartz sand, pyrite and gypsum. It is a hard rock. On the other hand, clay is a putty like substance composed of extremely small particles. It is not even a rock because it is composed of only one particle. For anything to be a rock, it has to be composed of more than one mineral.

2. The characteristics of shale and the way to identify it.
       Shale is a sedimentary rock. It can be gray, black, brown, dark green, blue or even red. It is fine-grained. When it gets wet, shale usually smells like wet mud. There are two steps to identify and classify shale. First, it is composed of fragments of pre-existing clay. In other words, it is capable of being taken apart or return to its initial shape which proved that it is a sedimentary rock. Second, when being cut, the fragments are thin layers(clay).

                                                                                               3. The process of the forming of the shale.

4. Shale with a lot of fossil evidences(By BC)

Shale is made up from the cementing of the clay which is typically a weathered feldspar coming from the granite. The clay was settled under water, being compacted and cementing into shale. Clay sediments settled in the Don Valley River which was just above the Brick Works long ago. When buried and compacted under the water, the clay cementing into the shale. Around 12,500 years ago, the glacier melted and withdrew to the north. So, it left a large amount of shale exposed to the air like what it is like today.

5. Lots of fossil evidences(By BC

4. The reasons of the presence of the large deposit of clay and shale in the Don Valley Brick Works.
Thousands of years ago, the ice age left a glacier river at the area surrounding the Don Valley. The Don Valley was the mouth of the glacier river. Because the shale and clay can only be found near the river, bay or beaches or other decomposed area. As a result, the river is a great source of producing shale.

6. Shale with some fossil evidences. Hint: the black dot is a fossil(By BC)


		7. The Area to find shale(By Mr.P)

5. The area to find shale

This picture shows that shale normally settles in slow moving water. It can also be found in depositional area such as lake, lagoonal deposits, river deltas, floodplain and offshore from beach sands.