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Home , Law of superposition, Lithification, Making North America

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E.8.7.1-4 Important Vocabulary E.8.7.1-4 1. Igneous 2. metamorphic 3. Sedimentary 4. Cycle 5. Relative age/dating 6. Law of superposition 7. Law of Cross-cutting Relationships 8. Law of Original Horizontality 9. Correlation 10. Index I Can …

– Create a model of the and relate the fossil record to how rocks are formed – Construct and analyze scientific arguments to support claims that most provide evidence that from Earth’s past was diverse and relationships exist from the past to current life forms – Use scientific evidence to create a of Earth’s history that indicates relative dates of strata and the fossils found within the strata using index fossils – Research and provide evidence to document claims about how has been shaped both gradually and through mass extinctions throughout Earth’s varying geological conditions Sedimentary Rocks

How does the Rock Cycle help provide evidence for past life?

E.8.7.2 Create a model of the processes involved in the rock cycle and relate it to the fossil record. STEM Careers Associated with Unit

– – Museum director – Paleontologist – Geochemist – Environmental Field – Engineering geologist Technician – Excavator – Drilling Project Manager – NASA Geologist – Field Semiologist – Hydrogeologist 3 Main types of Rocks

• Sedimentary • Metamorphic • Igneous

Rocks are classified by how they form Igneous Rocks

– Igneous rock: forms when molten rock (magma) cools and hardens – 2 types – Classified by where they form – Intrusive – Extrusive Igneous rock locations Intrusive Igneous Rock

– Intrusive igneous: cooling of magma takes place slowly beneath Earth’s surface – Rocks are often very hard and have more colors. granite Extrusive Igneous Rock

– Cooling of lava takes place rapidly on Earth’s surface Obsidian Pumice – Rock can either be very light and airy or the rocks can be glassy Metamorphic Rock

– Metamorphic rock: forms when any type of rock is changed into a different type of rock – Changes is due to great heat and/or pressure on an igneous or Gneiss Sedimentary Rock

Limestone

• Sedimentary rock: forms when (sand, gravel, and dirt) are pressed together over and become a rock • form in layers. • This process is called lithification • Sediments are: • Rock pieces • grains • Shell fragments Sedimentary Rocks

Limestone

Shale

Sandstone

https://www.pbslearningmedia.org/resou rce/nvmn-sci-grandcanyon/wgbh-nova- making-north-america-uncovering-layers- Granite of-the-grand-canyon/ How do sediments form?

– Sediments form through the processes of weathering and of rocks exposed at Earth’s surface

erosion Sedimentary Rock con’t….

– Sedimentary rocks can also form from the chemical depositing of materials that were once dissolved in water

– When water evaporates, gypsum are left behind and form rock Sedimentary Rocks

– Most Fossils are found in sedimentary rocks The Rock Cycle The Earth Recycles Rock

– The rock cycle is an ongoing series of processes inside Earth and on the surface

– Slowly changes rocks from one kind to another

– It is not one continuous circle – Any type of rock can change into another type What drives the Rock Cycle?

– Plate movement drives the rock cycle – Subduction (1 plate pushed under another plate) – Re-melts rock into magma – Mountain building – Folding, faulting, uplift – Exposes rock at the surface to be weathered and eroded Copy Me 1. What type of rock will for at #2 in the rock cycle? Review 2. What evidence do you have to support your answer? FOLDABLE TIME How does Rock help provide evidence for Earth’s History?

Relative Dating & Fossils

E.8.7.1 Use scientific evidence to create a of Earth’s history that depicts relative dates from index fossil records and layers of rock (strata).

E.8.7.3 Construct and analyze scientific arguments to support claims that most fossil evidence is an indication of the diversity of life that was present on Earth and that relationships exist between past and current life forms. A Little Bit of History…

• The history of geologic time begins with the human interest in mining in the 1500s and 1600s

• People began to identify strata (rock layers) by the types of fossils that were found within them.

• Two scientists were credited with contributing the most research to this area -- Nicolaus Steno and James Hutton Nicolaus Steno

Adapted two geologic principles

1. Law of Superposition : sedimentary rocks are found with the oldest on the bottom and youngest on top. • E.x. Paint layers

2. Principle of Original Horizontality: If left undisturbed rock layers will stay in horizontal order James Hutton

18th-century Scottish physician and farmer

. Studied his farm land for geologic changes *The Present is the Key to the Past . Principle of Uniformitarianism: geologic processes from the past are the same as the current geologic processes.

E.x. What happened then happens now There are two types of Geologic Dating

– Absolute – Determines how many years old something is – Relative – Used to determine if one thing is younger or older than another Tools used to determine

Relative Age/dating Absolute Age

– Law of superposition – Using – Correlation of rock layers – Use of index fossils

– Relative Dating/age is when you give the age of a rock or fossil compared to another rock or fossil. (younger or older) – Example: Rock B is OLDER than Rock A. – An actual age in years is not determined. Rules of Relative Dating

1. Law of Superposition: When sedimentary rock layers are deposited, younger layers are on top of older deposits. – Fossils are generally the same age as the rock layers in which they are found – Animal remains are deposited along with the sediments that will turn into sedimentary rocks Rules of Relative Dating

2. Law of Original Horizontality: Sedimentary rock layers are deposited horizontally. If they are tilted, folded, or broken, it happened later. Law of Original Horizontality Rules of Relative Dating

3. Law of Cross-Cutting Relationships: If an igneous intrusion or a fault cuts through existing rocks, the intrusion/fault is YOUNGER than the rock it cuts through – What is “B”? – Place the layers in order from oldest to youngest

– - breaks in geologic time where rock layers erode away or when isn’t deposited – a new rock layer can formed atop an eroded surface – rock has been eroded, so you have a missing section of time in the rock record. Unconformity – What section of time is missing? Angular Unconformity

• What events What type of might have What caused the rocks formed caused the rock angular unconformity? above? layers to become tilted? • Why is the top flat? Angular Unconformity Correlation

– Rock layers in different places can be correlated or matched up by matching up the rocks and fossils in the layers. 1. Which layers Correlate? 2. What does that mean about those layers? 3. Are there any areas of unconformity? https://youtu.be/sgPnnzou0og

America Museum of natural History https://www.youtube.com/watch?v=9f5HehQovx8

. The study of fossils . Fossils Records are the history of life as documented by all fossils ever found on Earth

What kinds of rocks are most fossils found in? What is a fossil? • A fossil is the preserved remains of a once- living organism.

What do fossils tell us? • Give clues about organisms that lived long ago • Help to show that evolution has occurred. • Provide evidence about how Earth’s surface has changed over time. • Help scientists understand what past environments may have been like. •Marine fossils indicate a marine environment •wooly mammoths indicate a cold environment HOW IS A FOSSIL FORMED?

– 1. Sediment – An animal is buried by sediment, such as volcanic ash or silt, shortly after it dies. Its bones are protected from rotting by the layer of sediment. – 2. Layers – More sediment layers accumulate above the animal’s remains, and minerals, such as silica (a compound of silicon and oxygen), slowly replace the calcium phosphate in the bones. – 3. Movement 1.– SedimentMovement of tectonic plates,2. or giantLayers rock slabs that make up Earth’s3. Movement surface, lifts up the sediments4. andErosion pushes the fossil closer to the surface. An animal is buried by More sediment layers Movement of tectonic Erosion from rain, sediment,– 4. Erosion such as accumulate above the plates, or giant rock rivers, and wind wears volcanic ash or silt, animal’s remains, and slabs that make up away the remaining rock – Erosion from rain, rivers, and wind wears away the remaining rock layers. Eventually, erosion or people digging for fossils shortlywill after expose it dies. the preserved Its remains.minerals, such as silica Earth’s surface, lifts up layers. Eventually, bones are protected (a compound of silicon the sediments and erosion or people from rotting by the and oxygen), slowly pushes the fossil digging for fossils will layer of sediment. replace the calcium closer to the surface. expose the preserved phosphate in remains. the bones. FIVE MAIN TYPES OF FOSSILS

Petrified Molds and Carbon Fossils Casts Films

Trace Preserved Fossils Remains PETRIFIED FOSSILS

• The word “petrified” means “turning into stone.” • Form when minerals replace all or part of an organism.

PETRIFIED FOSSIL The Field Museum in Chicago displays a fossil of a Tyrannosaurus rex. MOLDS AND CASTS

• A mold forms when hard parts of an organism are buried in sediment, such as sand, silt, or clay. MOLD FOSSIL This mold, or imprint, is of •Hard parts completely dissolve over time, leaving an extinct mollusk called behind a hollow area with the organism’s shape. an ammonite.

• A cast forms as the result of a mold. •Water with dissolved minerals and sediment fills the mold’s CAST FOSSIL This ammonite cast was •Minerals and sediment that are left in the mold discovered in the United make a cast. Kingdom.

CARBON FILMS

• All living things contain an element called carbon. • When an organism dies and is buried in sediment, the materials that make up the organism break down leaving only carbon that show an organism’s parts FERN FOSSIL This carbon-film fossil of a fern is more than 300 million years old. TRACE FOSSILS

• Trace fossils show the activities of organisms. • An animal makes a footprint when it steps in sand or mud. •Over time the footprint is buried in layers of FANCY FOOTWORK sediment. Then, the sediment becomes solid This footprint was rock. found in Namibia, Africa. PRESERVED REMAINS Some organisms get preserved close to their original states.

IceAmber AnAn organism,organism, suchsuch asas ana woolly insect, is Tar An organism, such as a mammoth, is mammoth,trapped in adies tree’s in asticky very coldresin region. and dies. Its Morebody resinis trapped in a tar pit and dies. The tar soaks into its frozencovers init, ice,sealing which the preserves insect inside. the organism It hardens— eveninto its bones and stops the bones from decaying. hair!amber. Amber Tar Ice An organism, An organism, An organism, such as an insect, such as a such as a woolly is trapped in a mammoth, is mammoth, dies in tree’s sticky resin trapped in a tar pit a very cold region. and dies. More and dies. The tar Its body is frozen resin covers it, soaks into its in ice, which sealing the insect bones and stops preserves the inside. It hardens the bones from organism—even into amber. decaying. its hair! Index Fossils

– Index Fossils - A unique fossil that are widely distributed lived during a specific time used to tell the relative age of rock layers (strata) Specific index fossils for every time period Eurypterus NY State Fossil

Silurian index fossil Index fossil: Based on the index fossil, about how old is rock layer B?

Trilobite: Index fossil for the Age: 590-250 mya

Location A Location B Location C

Rock layer 1 W W W Z

Rock layer 2 W Z Y Z

Rock layer 3 W X X X Z

Which letter would make a good index fossil? How do Rock Layers help provide a timeline for major events & life in Earth’s History?

Geological Time Scale

E.8.7.4 Use research and evidence to document how evolution has been shaped both gradually and through mass extinction by Earth’s varying geological conditions (e.g., , meteor impacts, and volcanic eruptions). Ted Talk: Earth’s History in one Year

– https://youtu.be/tkxWmh-tFGs The is a type of calendar use to put events in their proper order Geologic Time

– Earth is estimated to be around 4.6 billion years old based on the rock and fossil record.

– Geologic time is broken up into sections based on major changes in Earth . – Ex. Mass extinctions and dominant fossils Divisions of Geologic Time Periods are divided into Epochs

Eras are divided into Periods Cenozoic Ceno - recent

Eons divided into Mesozoic Largest Meso - middle Division: 4 : Eons Paleozoic Paleo - ancient

Precambrian

*Zoic - life Divisions of Geologic Time

Eras are Periods are divided into divided into Eras: Periods Epochs Pre- Era Known as the “Age of Bacteria”

Age: – 543 million years ago to ~ 4 billion years ago (?) – Oldest – Longest era because we know so little about the earth that long ago Life: – Very little life: only basic forms including bacteria, the oldest fossils ever found, seaweed, jellyfish, and worms

– Photosynthesis of the seaweed added oxygen to the early atmosphere, paving the way for land life. First Life of the Pre-Cambria

– One celled plants (algae) entered the fossil record approximately 3 b.y.a

– Large colonies of this algae are called stromatolites. Microbe-rich Stromatolite Reefs

– Located in Shark Bay, Australia – First sources of oxygen on Earth – Flourished throughout the planet's shallow waters 3.5 billion years ago – Extremely rare today. Atmospheric Changes caused by new Life

Through photosynthesis, O2 was released into the atmosphere and allowing other organisms to eventually evolve. Eon *Zoic = “animal life There are 3 eras that the Phanerozoic Eon can be divided into based on the dominate type of different fossils found 1. Paleozoic: marine life 2. Mesozoic: birds and reptiles 3. Cenozoic: Mammals Paleozoic Known as the “Age of the Fish”

Age: • 543 million years ago to 248 million years ago Life: • The beginning had with an explosion of life in the sea • trilobites, shellfish, Fish • Middle to the End life appears on land • Forests and jungles • Ferns • Land animals evolved • Amphibian Events: • Pangaea formed • Largest mass extinction ever at the end of the Paleozoic. 90% of species became extinct. Paleozoic Organisms Carboniferous Time

In Europe the Mississippian and Pennsylvanian periods are together called the Carboniferous period. Vast swamps and forests from that time created the huge coal beds found throughout eastern United States. Mesozoic Era “Age of the Reptiles/”

Age: – 248 mya- 65mya Life: • Reptiles are the dominant life on land. • Dinosaurs exist. • Birds appear. • Forests of trees appear Events:  Pangea broke apart during this period.

 Dinosaurs become extinct in a mass extinction at the end of the Mesozoic. Mesozoic Era: Age of Reptiles

Jurassic Period: Dinosaurs ruled the Earth Reptiles: Appeared in the Permian and quickly became the dominant life form. 78 …until Dinosaurs took over.

They ruled the planet throughout the Mesozoic era (the “Age of Dinosaurs”). Birds

Some of the dinosaurs are thought to have evolved into birds.

Archaeopteryx is the oldest fossil bird found to date. Dinosaur Extinction

1. Volcanoes erupt and fill 2. Meteorite the atmosphere with CO2 and gasses that BLOCK impact causes the sun light preventing multiple natural plant life……. disasters Evidence of a Meteorite

– Layer of Iridium in rock layers TED Ed - Mass Extinctions

– https://ed.ted.com/lessons/when-will-the-next-mass-extinction-occur-borths- d-emic-and-pritchard Cenozoic “Age of the Mammals”

Age: – 65 mya- present Life: – Life: Large mammals appear, Humans appear Events:

Ice Ages occur and ice sheets advance  Plate movement caused mountains to form, volcanoes, & earthquakes Cenozoic Era: Age of Mammals Mammals first appeared in the Mesozoic as small rodents. After the dinosaurs were erased at the end of the Mesozoic, Mammals quickly evolved to become the dominant life form. Present

We live in the – Holocene – Quaternary period – Cenozoic era – https://youtu.be/8qnnoePeHlk

– Graphic novel: History of the Earth in 5 minutes