1 / 11

Sedimentary Rocks

Sedimentary Rocks. D. Crowley, 2008. Sedimentary Rocks. To know how sedimentary rocks are formed. Sedimentary Rocks. Compare the sand and the sedimentary rock sandstone What are the differences between them? Why is the sandstone so much harder?. Sand. Sandstone. Sandstone Formation.

lefty
Télécharger la présentation

Sedimentary Rocks

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Sedimentary Rocks D. Crowley, 2008

  2. Sedimentary Rocks To know how sedimentary rocks are formed

  3. Sedimentary Rocks • Compare the sand and the sedimentary rock sandstone • What are the differences between them? Why is the sandstone so much harder? Sand Sandstone

  4. Sandstone Formation • Sedimentary rocks often have layers showing deposition of sediment through different time periods • Sedimentary rocks consist of lots of small grains – these grains are often weakly held together, so the rocks are soft and crumbly (as well as often being porous) • Sedimentary rocks often contain fossils

  5. Sandstone Formation • Sandstone was originally loose sand on the floor. Since then the grains have become stuck together • You are going to investigate how this could have happened…

  6. Sedimentary Experiment • Smear a small amount of petroleum jelly around the inside of the syringe • Make some sand damp in a plastic cup by adding a small amount of water to it: fill you syringe with this damp sand • Put your fingers over the end of the syringe and press the plunger in as hard as you can • Take your thumb away and gently push the sand pellet out of the syringe onto a piece of paper • Repeat this using damp sand and gravel; then repeat again using damp sand and plaster of Paris • Leave your pellets to dry for 10-15 minutes

  7. Sedimentary Experiment • Whilst the pellets dry, predict which will be the strongest and why • Then design an experiment to test their strength and carry this out

  8. Sedimentary Formation • Rocks are deposited at the bottom of a lake / sea (after being transported from rivers) • The deposited rocks build up in layers, called sediments (this is sedimentation) • The weight of the sediments on top squashes the sediments at the bottom (compaction) • The water is squeezed out from between the pieces of rock and crystals of different salts form – the crystals form a sort of glue that sticks or cements the pieces of rock together (cementation) which may take millions of years Sedimentation  Compaction  Cementation

  9. Sedimentary Formation

  10. Sedimentary Formation

  11. Sedimentary Formation • Sedimentary rocks has the oldest layers at the bottom and the youngest layers at the top • Sedimentary rocks may contain fossils of animals and plants trapped in the sediments as the rock was formed – fossils are only found in sedimentary rocks

More Related