the rock and fossil record

Chapter 3Mr. Monson’s Science Class

Earth’s Story and Those Who First Listened James Hutton-

Scottish Farmer spent 30 years

studying rock and rock formations in England and Scotland

His observations led to the founding of modern Geology

1729 - 1797James Hutton

Hutton’s Theory of the Earth Hutton collect his

notes in 1788 He writes the key to

understanding Earth’s History is all around us today

Uniformitarianism – geological processes that occur in the past can be explained by current geological processes

Siccar Point in Scotland – One of Hutton’s observation Points

Catastrophism

During Hutton’s time most scientist thought the earth was only a few thousand years old

Mountains and seas formed in sudden, rare events

Catastrophism – geologic changes occur suddenly

Mt. Saint Helens Erupts 1980

The Battle Continues . . .

Charles Lyell published Principles of Geology

1830 -1833 three volume collection

Successfully challenged catastrophism

Earth’s changes gradual

1797 – 1875 Charles Lyell

Modern Geology - Both

Modern geologists Stephen J. Gould

Challenged saying catastrophes do play an important role in Earth’s History

Both Uniformitarianism and Catastrophism are right

1941- 2000 Stephen J. Gould

Modern Geology - Both

Some Scientists think . .

An asteroid struck earth

65 million years ago

Caused extinction of dinosaurs

Through global debris raining down for decades

Other Modern Theories

Other current theories include – volcano(s) erupting changing the earth’s temperature

Some think the Earth got too hot . . .

Some think the Earth got to cold from the volcanic activity

Paleontology – The study of Past Life

Paleontology is the study of past life (fossils)

Paleontologists are the scientists that study past life Specialize

Invertebrates Animals (no back bones)

Vertebrates Animals (back bones)

Paleobotantist study plants

Others reconstruct past ecosystems

Paleontology – The study of Past Life . . .

1905 – 2001 Edwin Colbert Vertebrate Paleontologist

Found 12 Coelophysis on Ghost Ranch in New Mexico

Edwin Colbert

Named Staurikosaurus

Relative Dating: Which Came First Scientist have to

figure out the sequence of events in Earth’s History

Keys to identify older or younger object

* Rocks* Fossils

Superposition

Younger rocks lie above older rocks if the layers of rocks have not been disturbed

New Rock

Old Rock

Middle Age Rock

Disturbing Forces

Some rock sequences are disturbed by the forces of nature

Tilted Folded Broken apart’ Upside down

Over most of Breadalbane, between 740 and 515 million years before the present day, south of Glen Lyon, these metamorphic rocks are relatively flat-lying. The unusual thing about them, however, is that as a result of folding they are upside down!

Geologic Column An ideal layer of

rock that contains all the known fossils and rock formations arranged from oldest to youngest

Oldest rocks on bottom and youngest rocks on top

Geologic Column . . .

Geologists rely on geologic column to help identify layers in puzzling rock sequencing

Constructing the Geologic Column Grand Canyon

Disturbed Rock Layers. . .

Features cut across rock layers Features are younger than rock layers Rocks had to be there to fault, fold, tilt,

erode . . .

Disturbed Rock Layers

Fault is a break in the Earth’s Crust along which blocks of the crust slide relative to one another

Disturbed Rock Layers . . .

Intrusion – molten rock from the Earth’s interior that squeezes into existing rock and cools

Follow the dark igneous rock

Disturbed Rock Layers. . .

Folding occurs when the rock layers bend and buckle from Earth’s internal forces

Disturbed Rock Layers

Tilting occurs when internal forces in the Earth slant rock layers

Events that Disturb Rock Layers Geologist assume

rock layers are originally formed in horizontal layers

The events that fold, tilt or intrude happen after the rock forms so they are newer

Gaps in the Record – Unconformities. . .

Faults, intrusion, folding and tilting make dating rocks difficult

Unconformity is a break in the geological record created when rock layers are eroded or when sediment is not deposited for a long time

Types of Unconformities Disconformities – parts of a sequence of parallel

rock layers are missing

Represent thousands to millions of years of missing time

Types of Unconformities

Nonconformities – a horizontal sedimentary layer lies on top of an eroded layer of older intrusive or metamorphic rocks

Represent millions of years of missing time

Types of Unconformities

Angular Unconformities – are found between horizontal layers of sedimentary rock and layers of rock that have been tilted or folded

Represent millions of years of missing time

Types of Unconformities

Looked at all the unconformities in this picture – can you see the millions of years of missing records

Rock Layer Puzzles

Rock layer sequence can be affected by more than one event

Intrusive rock may have squeezed into layers that contain deformity

Geologist use their knowledge of events to piece together the rock layer jigsaw puzzle

Fossils Fossil is the remains or physical evidence of an organism preserved by geological processes

Fossils in Rocks When an organism dies

it usually decays or is quickly eaten

Sometimes an organism is quickly buried by sediments when it dies

Sediments slow decay

Bones and shells decay slower

Hard parts are preserved more than soft tissue

Fossils in Amber Amber –tree sap which hardens

quickly Insects or small animals get caught in it Some of the best fossils of insects Also frogs and lizards

Petrifaction

Petrifaction – process in which tissue of an organism are replaced with minerals

Petrifaction. . .

Permineralization – is where the pore space (hard tissue) is filled with the mineral

Bone permineralization with silicon, calcite or pyrite . . .

Petrifaction. . . Replacement – is the process in which the

minerals tissues are completely replaced with minerals

Fossil in Asphalt

Asphalt wells on Earth’s surface are thick, sticky pools

La Brea asphalt deposits near Los Angeles CA

Trapping organisms for 38,000 years

Fossil in Asphalt. . .

Scientist learn a lot about past form Asphalt pools

Frozen Fossils Found remains of a

20,000 year old woolly mammoth in Siberian Tundra in 1999

Frozen Fossils. . .

Freezing slows decay

Many type of frozen fossils are preserved from the last ice age

Frozen shrimp fossil

Frozen baby mammoth

Other Types of Fossils

Trace Fossils – is a fossilized mark that is formed in soft sediment by the movement of animals Foot prints - tracks Burrows

Other Type of Fossils . . .

Mold – the cavity in the rock where the plant or animal was buried

Cast – fossil type that forms when sediments fill the cavity left by decomposition

Using Fossils to Interpret the Past

Fossil record gives us part of the Earth’s History Know more about

hard body then soft bodied animals

Incomplete because most organisms never became fossils

Using Fossils to Interpret the Past. . . Fossils reveal

changes in Earth’s environment Sea fossils on

mountain tops Can help scientist

reconstruct ancient coastlines

Can help tell what the weather was Cooer Wetter desert

Fossils from ancient seas left in Burgess Shale on the top of a mountain at Walcott Quarry, in Yoho National Park, British Columbia, Canada

History of Changing Organisms

Older rocks contain different organisms than younger rocks

Fossil record is incomplete

Scientists look for similarities in ancient organisms and their closest living relatives

Using Fossils to Date Rocks

Index fossil - found in the rock layers of only one geologic age and that is used to establish the age of the rock layers

Ammonites - Tropites

Fossils of Tropites (marine mollusk) Living relative - squid Lived between 230 – 208 million years ago Rock they are found in is 230 – 208 million years

old

Trilobites Trilobites or

Phacops– extinct Lived 400 million

years ago

Living relative – hermit crab

Rocks they are found in is 400 million years old

References http://www.gjenvick.com/images/Periodicals/HarpersMagazine/1897/ScienceAtTheBeginningOfTheCent

ury/Illustration-05-JamesHutton-250.jpg Retrieved 2/16/10

http://www.lawrence.edu/dept/geology/siccar.point.gif Retrieved 2/16/10 http://scrapetv.com/News/News%20Pages/Science/Images/mount-st-helens-eruption.jpg Retrieved

2/16/10 http://www.stephenjaygould.org/images/stephenjaygould.jpg Retrieved 2/16/10 http://newsimg.bbc.co.uk/media/images/38938000/jpg/_38938379_dino_bbc_203.jpg Retrieved

2/16/10 http://www.zworld2.com/MRSZWORLD/Dinosaurs/VOLCANOTHEORY.gif Retrieved 2/16/10 http://upload.wikimedia.org/wikipedia/en/d/d6/Edwin_Harris_Colbert_1.jpg Retrieved 2/16/10 http://static.howstuffworks.com/gif/dinosaur-images-036-resize.jpg Retrieved 2/16/10 http://images.google.com/imgres?imgurl=http://static.howstuffworks.com/gif/dinosaur-images-064-

resize.jpg&imgrefurl=http://animals.howstuffworks.com/dinosaurs/dinosaur-bones2.htm&usg=__fULJnmVtjqG2LDhhs49ij1E32LU=&h=300&w=400&sz=30&hl=en&start=3&um=1&itbs=1&tbnid=uPSPNu7fPqjmtM:&tbnh=93&tbnw=124&prev=/images%3Fq%3Ddinosaur%2Bfossils%2Bin%2Brocks%26hl%3Den%26rlz%3D1T4ADBF_enUS276US277%26sa%3DN%26um%3D1 Retrieved 2/16/10

http://www.purchon.com/ecology/images/folds.jpg Retrieved 2/16/10 http://www.amberworkshop.com/i/amber_inclusions_plant_inclusions_insect_inclusions/collection_ambe

r_inclusion.jpg Retrieved 2/18/10

http://www.amberworkshop.com/i/amber_inclusions_plant_inclusions_insect_inclusions/collection_amber_inclusion.jpg Retrieved 2/18/10

http://imagecache2.allposters.com/images/NGSPOD/740311-FB.jpg Retrieved 2/18/10 http://crystalrivergems.com/products/fossils/images/DSCF0016.jpg Retrieved 2/18/10 http://www.gly.fsu.edu/~odom/1000/sediments/bedding.jpg Retrieved 2/18/10 http://www.explorebreadalbane.co.uk/imagebox/1424-F2-fold-in-Loch-Tay-Ls.JPG Retrieved 2/23/10 http://www.agiweb.org/news/evolution/paleo_geo_evol.html#null Retrieved 2/23/10 http://www.globalwarmingart.com/wiki/Wikipedia:Law_of_Superposition 2/23/10 http://dinosaurs.about.com/od/carnivorousdinosaurs/p/staurikosaurus.htm 2/23/10 http://www.nwcreation.net/geologycolumn.html 2/23/10 http://creationwiki.org/pool/images/thumb/2/28/Geo_time.JPG/400px-Geo_time.JPG 2/23/10

References . . . http://www.biocrawler.com/w/images/d/dd/Grand_Canyon_geologic_column.jpeg

Retrieved 2/23/10 http://www.eoearth.org/upload/thumb/3/32/Synclinal_folds_pic.jpg/250px-Synclinal_folds_

pic.jpg Retrieved 2/23/10

http://geomaps.wr.usgs.gov/socal/geology/inland_empire/images/guataemala.jpg Retrieved 2/23/10

http://www.npolar.no/geonet/picture_atlas/Sv03-01-22.jpg Retrieved 2/23/10 http://www.fas.org/irp/imint/docs/rst/Sect2/crumpled_%20fold.JPG Retrieved 2/23/10 http://www.purchon.com/ecology/images/folds.jpg Retrieved 2/23/10 http://raider.muc.edu/~mcnaugma/images/Structures/3L99-4%20I70Roadcut%20denver.j

pg Retrieved 2/23/10

http://www.worldofstock.com/slides/NEA2607.jpg Retrieved 2/23/10 http://reynolds.asu.edu/sierra_cobre/p_unconformity.jpg Retrieved 2/23/10 http://www.es.ucsc.edu/~es10/classnotes/images/Grand.Canyon.d.jpg Retrieved 2/23/10 http://geologicalintroduction.baffl.co.uk/wp-content/uploads/2009/01/disconformity.jpg

Retrieved 2/23/10 http://bp0.blogger.com/_osP51C3atIY/RgMLHeketNI/AAAAAAAAAsQ/MBfepekuJoU/s1600-h/

Taum-Sauk_precam-cam-unconformity.jpg Retrieved 2/23/10

http://clasticdetritus.files.wordpress.com/2010/01/fff99.jpg Retrieved 2/23/10 http://farm4.static.flickr.com/3442/3801372763_7f52897222_o.jpg Retrieved 2/23/10 http://www.geolsoc.org.uk/webdav/site/GSL/shared/images/education_and_careers/

RockCycle/Processes/Crystallisation/Igneous%20intrusion%201.jpg Retrieved 2/23/10 http://lovingthebigisland.files.wordpress.com/2009/06/fossil-fish-1.jpg Retrieved 2/23/10 http://www.charmouthfossils.co.uk/shop/images/gcap_fossil_beach.jpg Retrieved 2/23/10 http://www.maropeng.co.za/images/uploads/fossil_lg.jpg Retrieved 2/23/10

References . . . http://dsc.discovery.com/news/2007/10/08/gallery/amber_zoom.jpg Retrieve

2/23/10 http://www.juniorengineering.usu.edu/workshops/amber/images/tree1.jpg

Retrieved 2/23/10 http://en.wikivisual.com/images/2/24/Petrified_wood_closeup_2.jpg Retrieved

2/23/10 http://www.kith.org/logos/pix/photos/scenery/petrified.jpg Retrieved 2/23/10 http://www.bone-yard.org/images/ty/petwooda.jpg Retrieved 2/23/10 http://www.womansday.com/var/ezflow_site/storage/images/media/images/06-wd

0809-pitch-lake/693507-1-eng-US/06-wd0809-Pitch-Lake.jpg Retrieved 2/23/10

http://www.tarpits.org/education/guide/art/page3a.jpg Retrieved 2/23/10 http://www.semp.us/_images/biots/Biot485PhotoQ.jpg Retrieved 2/23/10 http://i.livescience.com/images/051219_mammoth_head_02.jpg Retrieved

2/23/10 http://www.foxnews.com/images/299650/1_61_mammoth_frozen_1.jpg 2/23/10 http://www.environmenttimes.co.uk/images/sce/News/Antarctic-fossil.jpg

Retrieved 2/23/10 https://courseware.e-education.psu.edu/courses/earth105new/graphics/L02_fossil_

hpl922.jpg Retrieved 2/26/10

http://www.fossilmuseum.net/Fossil_Sites/solnhofen/Stenophlebia-latreilli/EP013B.jpg retrieved 2/26/10

http://eostone.com/images/home-fade/turtle.jpg Retrieved 3/1/10 http://almashriq.hiof.no/lebanon/500/550/551/abisaad/fossils-981025-06-528.jpg

Retrieved 3/1/10

References. . .

http://www.ucdavis.edu/images/features_level2/0209/darwin/grosberg_full.jpg Retrieved 3/1/10

http://www.geology.ohio-state.edu/~vonfrese/gs100/lect29/xfig29_04.jpg Retrieved 3/1/10

http://www.ing.uni.wroc.pl/~pracz/dyd/obr_skam/trop1.jpg Retrieved 3/1/10 http://blogs.smithsonianmag.com/aroundthemall/wp-content/files/

2007/11/2007-7438-trilobites.jpg Retrieved 3/1/10 http://www.afsc.noaa.gov/kodiak/images/photo/crabak_herm.jpg Retrieved

3/1/10