History of the Earth

History of the earth

Notizen:

• Green earth since 400 million years
• Moon was closer

• Cloud instertellar dust/gas (Helium, hydrogen) -> condensted, colpased, contracting -> high presure, heat -> new element (hydrogen becoming helium) -> radioation (sun light) -> solar system -> futher contracting -> planets -> living
• Supernova: nuclear fusion of a star -> energy (gamma-rays) -> stardust -> new elements
• Dust gathered/collected -> garvity (sucked rocks etc to the earth) -> impact energy in center of earth -> vulcanos
• Big bang -> energy -> expantion from energy -> galaxy will be teared apart -> end of galaxy? Or collapses together again, new supernova -> end?
• Life-form potential between 0-100°C
• Milky way -> 200 Billions stars with potential life
• Eon: Hadean (4.5-3.85 Billion years) -> hellish, hot, bombardement from other compets etc

 -> no possible life-form -> upper layer partical became solid

• Eon: Archean (3.85 -2.5 Billion year) -> liquid surface -> maybe first evidence of

life-forms (oxygen free) -> cyanobacterias -> waste: oxygen

• Eon: Proterozoic -> no plants nothing, little oxygen, ozeans, desserts, primitiv life-forms -> bacterias
• Object hit the earth -> upper layer was scrateched off -> moon (less dense) -> only explantion
• Heat in earth: 1/3 Kernspaltung, 2/3 impact energy
• Moon solid -> too cold
• Earth liquid in middle -> earth tectonic
• Old rocks -> not red -> no oxygen -> iron won’t rust

• Black smokers, maybe first life-forms underwater
• Foam on waves, organic material
• Eon: Phanaerozoic: life-forms
• Era: Palaeozoic: primitiv sponges, Stromatolites (housing of bacterias, shores)
• Period: Cambrian

• Canyons: horizontal layers

Valley: random layers

Homework:

• A short history of the earth

1. On page
2. Differences between early life forms from those of today?

Early: single cell, bacterias, no oxygen needed, simple structure, under microscope visible, in water, anerobic (no oxygen), asteroids, gases, erruptions, strong radiation

Today: multiple cell, all kind of life-form, mostly oxygen needed, big, complex, live on land

1. Why would it be impossible for us to surive in the early life forms those of today?

No oxygen, no land, only water

1. What is meant by Oxygen Catastrophy?

Time period that had too many bacterias what caused a massiv loss of oxygen, lots of life-forms exstincted again. Bacterias produced too much oxygen -> killed themselves

1. How could scientists find out the time when oxygen level started to rise?

Due de rust of iron in contact with oxygen.

1. Why radiation declined? Important for life?

A Ozon layer evolved what made living on earth possible, cause radiation would damage creatures and cause high temperatures.

1. Dinosaurs lived on Rodinia?

No, Rodinina is much older, no creatures there yet.

1. Why do scientists believe life was almost exstinct in Proterozoic Eon?

Due the massive ice over the ozeans very little light could get through, lots of life-forms died.

1. How is it possible for geologists map the occurence of life forms?

Due fossils that can be found. Deposits in rocks, minerals, fossils.

1. What is understood by the term «Cambrian Explosion»?

One means that suddendly like through an explosion lots of multiple-cell-creatures appeared on earth. Life-form poping up mostly in ozean, multiple-cell.

Teamwork

1.  Wich events mark the beginning and the end of the Paleozoic?

Events marking beginning and end of Paleozoic:

-Beginning: Cabrian Explosion

-End: Exstiction

1. Name for all of the Palaeozoic periods one or two typical life forms.

Cambrian: Trilobites (arthropods), jellyfish

Ordovician: Seastar, Seeigel

Silurian: horsetail

Devonian: fishs, sharks, coelacanth (first one with 4 feet), centipedes (arthropods), first amphibians (frog like), big forest started to grow

Carboniferous: dragonflies, big forest, black coal of forest (lots of layers, reason for name), reptiles like animals/dinosaurs (Edaphosaurus), centipedes (up to 1m, higher oxygen content, dead-end-trachea, have to become bigger), reptiles (thick, dry skin, lung more efficiant), swamps

Permian: Dinosaur like reptiles (dimetrodon), hippo like animals, «Perm» town in Russia

• Dramatic event: Great Dying: mass extinction

Mesozoic Era: 250-65 MA

-Trassic:

-Dinosaurs

-T-Rex possible just eating killed animals or hunting? Strong backlegs

-dinosaurs also living in water

-Jurrasic:

-Allosaurus (biggest predator)

-no T-Rex!

-long tail to balance body (Diplodocus)

-murge between reptiles and birds (Archeaopteryx)

-Cretaceous:

-biggest dinosaurs (Sauroposeidon)

-too big, needed too much food, too slow, circulatory system problems

-Torosaurus (horns for fighting)

• Dramatic Event: Cretaceous-Paleogene extinction event (KT-Boundary)

-took about 1 Million years to kill all dinosaurs

-10km wide

-lots of iridium on earth -> Dust -> all over planet

-no prove for reason for exstiction of dinosaurs

-maybe eco-system collapsed through that?

Era: Cenozoic:

-Mammals

-wulfs

-mammoths

-Pleistocene: ice age: mammoths, early humans, glaciers grew

-Halocene: modern world

1. What was the cause for the «oversize» of some animals during Carboniferous?

Lots of oxygen, bigger life-forms could evolve, due breathing systems

1. What’s the reason for the typical pattern of stripes in Carboniferous?

Conditions were reversed (glacier, glacial melt, ozeans, swamps, plants, coal seams, cyclic flooding, drying

1. Look at the diagram on page 3. Sometimes geologists speak of «The Big Five» but unlike safari game-spotters.

Big 5 mass extinctions

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