Biotic Rocks

What do these rocks have in common?What do you see that makes you say so?(Be as specific and as scientific as you can.)

CoalLimestoneFossilCoralThe Organisms Chapter of the Rock StoryBiotic RocksStill needs revision.Get some coral and coal for the kids to look at.Horn Coral in with fossilsBrain Pop: Fossils

Fossils:Fossils can tell us about the history of life on earth.Fossils can tell us about the climate on earth.Fossils can help us date rock layers.

Types of Fossils - Body

Frozen

Amber (tree sap)Peat Bog

Bones in rockShell in rock

LightningTypes of Fossils - Trace

Gastroliths (stones to aid digestion)Coprolite (poo)Bite/gnaw marksTracksBurrowsTypes of Fossils - Mold

Types of Fossils - Cast

Natural vs. Artificial?Pompeii, ItalyBrain Pop: Fossil Fuels/Fossils

Coal:Plants that live in swampy/marshy habitats die and turn into peat.Peat is compressed over the course of millions of years and turned into coal.

Brain Pop: Coral

Coral:Coral produces a hard structure that serves as a sort of skeleton. When each generation of corals die their skeleton is left behind, building up very slowly year after year. Coral Castle in Miami, FL

Coral reefs are home to 25% of all marine speciesCoral often grow up around a volcano as it erodes.

AtollLimestone:Small marine invertebrates (salt water animals without backbones) use a good deal of calcium in their shells.The animal dies and the soft parts rot away but the shells remain and build up layer after layer.The shells are compressed and turned into limestone.

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The Top Layer of Everest is LimestoneWhat does that tell you?

Limestone is made of dead coral and other sea shellsThese Horn Coral Fossils are Limestone

What we think the living organism may have looked like.Fossils:Rock layers can help date fossils and fossils can help date rock layers. Archaeopteryx is a very famous fossil.

Geologic Time DivisionsNotable Fossils or EventsTime Scale(Million years ago) CenozoicAbundant mammals, including humans

65 245 550

2,500 3,800

4,500 Mesozoic Cretaceous

Dinosaurs, flowering plants, birds, mammals Jurassic Triassic Paleozoic PermianGymnospermsMass extinction CarboniferousReptiles DevonianFirst amphibians, early insects SilurianLand plants OrdovicianFish CambrianMarine invertebrates ---trilobites dominant ProterozoicAquatic plants ArcheanEarliest life --- bacteria, algaeEarth formed

Geologic Time Scale

Using Fossils to Date Rock Layers: