hystorical geology

8/2/2019 Hystorical Geology

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Historical Geology

Tasks of the Historical Geology:

to restore geological past

to predict future (Aral sea)

distribution of mineral resources


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Historical geology studies the history of the development of Earth, its outer

layers and their interaction. It includes 4 elements: geochronology, stratigraphy,

paleogeography and paleotectonics.

Geochronology is a calendar of geological events covering 4,6 bln years. This

scale is based on radiometry dating of the rocks based on the ratio of natural

radioactive elements, isotopes and products of decay which occur with constant

rate.

Stratigraphy studies the laying of sedimentary and volcano rocks determining

their age based on the organic remains. Now it includes bio-, magneto- and

seismic-stratigraphy.

Paleogeography restores physical-geographical conditions of geological past(distribution of sea and continents, climate). It includes paleogeomorphology,

paleoceanology and paleoclimatology.

Paleotectonics studies the history of movements and deformations of the core

leading to the formation of mountains, platforms (kratons) and ocean trenches.


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Geological time scale

HISTORY OF THE UNIVERSE SINCE THE BIG BANG 15 BILLION (109) YEARS AGO

(THE SOLAR SYSTEM IS ABOUT 5 BILLION YEARS OLD)


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Formation of Solar system


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Future of the Sun

IN ABOUT 5 BILLION YEARS THEEARTH WILL BE FRIED AS THE SUN

BECOMES A RED GIANT.

ORBITUARY:

THE EARTH BECAME 10 BILLION

YEARS OLD.


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The main tasks of Historical geology:

1. Determination of the rocks age. Paleontology plays the

most important role in rock age determination . Absolute ageof magmatic, metamorphic and sedimentary rocks isdetermined with the help of radiological methods.

2. Restoration of physical and geographical conditions of the

earth surface: distribution of the seas and continents, relief,depths, salinity, temperature, climate...

3. Restoration and explanation of the history of volcano.

4. Restoration of tectonic movements history.

5. Studying of earth core development.


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In 1669 Danish scientist Niles Sten (16381686),working in Italy had formed 6 general principles ofStratigraphy.

1. The layer of the rock is the result of deposition in water.

2. The layer including the clusters of other layer has been formed after it.

3. Top layer is the youngest and bottom layer is the oldest.

4. The layer containing seashells or marine salt has been formed in the sea, if itcontains plants, it originates from river flooding or water flow.

5. The layer must have uncertain length and it can be traced across some valley.

6. The layer was deposited horizontally; if it is tilted it was subjected to turn. If theother layer lays above tilted layers, the turn occurred earlier this second layer. Inthis statements by Steno we see the beginning of stratigraphy and tectonics.

The aim of historical geology is combining of all historical geological data.

Antic philosophers Fales Miletian, Strabon, Empedokl, Aristotel...


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Outstanding geologists of XVIII century

Itailain Arduino in 1760 made first geological section based on the age.

German Verner (17501817) developed stratigraphic scheme of Central

Germany. Based on it, the geological history of Europe was reconstructed.

The outstanding significance had paleontological method offered by Englishgeologist Smith (17691839).

French Kuvie (17691832) and Broniar (18011876). At the same time

they made conclusions about how to date the layers based on the flora and

fauna remains.


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I.Relative geochronology

The theoretical basis was established by Nicholas Steno who introduced the law of

superposition, the principle of original horizontality, and the principle of lateralcontinuity in an 1669 work on the fossilization of organic remains in layers ofsediment.

Steno formed the principle of superposition in 1669: each underlaying layer isolder than overlaying layer.

1869 law ofGolovkinskiyWalter: in continous section of sedimentary rocksection that sediments can lay above each other which could be formed near on thesurface. During transgression or regression of the sea, the change of sedimentsvertically can correspond horizontal changing.

Principle ofSmith: the remains of same age contain the same or similar remains of

ancient organisms.

Hattonin XVIII law of intersection: the magmatic rock intersecting other rock isalways younger the rock it intersects, and other'the law of inclusion: theinclusion is always elder than the rock it includes.
http://en.wikipedia.org/wiki/Nicholas_Stenohttp://en.wikipedia.org/wiki/Law_of_superpositionhttp://en.wikipedia.org/wiki/Law_of_superpositionhttp://en.wikipedia.org/wiki/Principle_of_original_horizontalityhttp://en.wikipedia.org/wiki/Principle_of_lateral_continuityhttp://en.wikipedia.org/wiki/Principle_of_lateral_continuityhttp://en.wikipedia.org/wiki/Principle_of_lateral_continuityhttp://en.wikipedia.org/wiki/Principle_of_lateral_continuityhttp://en.wikipedia.org/wiki/Principle_of_original_horizontalityhttp://en.wikipedia.org/wiki/Law_of_superpositionhttp://en.wikipedia.org/wiki/Law_of_superpositionhttp://en.wikipedia.org/wiki/Nicholas_Steno


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Evolution of organic world is the base of geological dating

Methods of Dominant Animals (Index Fossils) is a first paleontologicalmethod which was introduced in Stratigraphy in XVIII-XIX cc. The broadapplication was given to it by German paleontologist Bronn in mid-XIX c.,and he created a first atlas of the general species.

For example: OboUis apollinistremadocian of Ordovician, Chonstites

mosquensisfor Moscow of Carbonic age, Cadoceras etatmaeKellovian, Cardioceras cordatumfor Oxford of Upper Jurassic,

Deshayesnes deshayesi, Acanthohoplkesfor Aptian, Leymeriella andAnahoplnesAlbian of Lower Carbonic, lemnitella mucronataforCampanian of Upper Carbonic.

The whole class can be general for the startigraphic subdivision. So,ceratits developed only in Perm and Triassic,archeoceratit in Lower Cambrian, trilobitesin Cambrian, Ordovicianand Silurian, they gradualy disappear in Devonian.


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Belemnites


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Biostratigraphy is the science of rock dating by using the fossils contained within

them. Usually the aim is correlation, that is a demonstration that a particular horizon in

one geological section represents the same period of time as another horizon at some

other section.

The fossils are useful because sediments of the same age can look completely

different because of local variations in the sedimentary environment. For example,

one section might have been made up ofclays and marls while another has more

chalkylimestones, but if the fossil species recorded are similar, the two sediments

are likely to have been laid down at the same time.

Ammonites, graptolites and trilobites are index fossils that are widely used inbiostratigraphy. Microfossils such as acritarchs, chitinozoans, conodonts

dinoflagellate cysts, pollen, spores and foraminiferans are also frequently used.

The law of the irreversibility of evolution process was firstly stated by Darwin. He

underlined that the extinct specy of organsim can never appear again.

It means that each complex of remains found in the layer reflects a certain stage of

organic world and is unrepeatable. Based on some types of organisms it is possible

to make planetary correlation. For example, Ordovician and Silurian graptolites,

Mesozoic ammonites, Palaeogene nummulites.
http://en.wikipedia.org/wiki/Fossilhttp://en.wikipedia.org/wiki/Sedimenthttp://en.wikipedia.org/wiki/Clayhttp://en.wikipedia.org/wiki/Marlhttp://en.wikipedia.org/wiki/Chalkhttp://en.wikipedia.org/wiki/Limestonehttp://en.wikipedia.org/wiki/Ammonitehttp://en.wikipedia.org/wiki/Ammonitehttp://en.wikipedia.org/wiki/Graptolitehttp://en.wikipedia.org/wiki/Trilobitehttp://en.wikipedia.org/wiki/Index_fossilhttp://en.wikipedia.org/wiki/Micropaleontologyhttp://en.wikipedia.org/wiki/Acritarchshttp://en.wikipedia.org/wiki/Chitinozoahttp://en.wikipedia.org/wiki/Conodontshttp://en.wikipedia.org/wiki/Dinoflagellatehttp://en.wikipedia.org/wiki/Pollenhttp://en.wikipedia.org/wiki/Sporeshttp://en.wikipedia.org/wiki/Foraminiferahttp://en.wikipedia.org/wiki/Foraminiferahttp://en.wikipedia.org/wiki/Sporeshttp://en.wikipedia.org/wiki/Pollenhttp://en.wikipedia.org/wiki/Dinoflagellatehttp://en.wikipedia.org/wiki/Conodontshttp://en.wikipedia.org/wiki/Chitinozoahttp://en.wikipedia.org/wiki/Acritarchshttp://en.wikipedia.org/wiki/Micropaleontologyhttp://en.wikipedia.org/wiki/Index_fossilhttp://en.wikipedia.org/wiki/Trilobitehttp://en.wikipedia.org/wiki/Graptolitehttp://en.wikipedia.org/wiki/Ammonitehttp://en.wikipedia.org/wiki/Ammonitehttp://en.wikipedia.org/wiki/Limestonehttp://en.wikipedia.org/wiki/Chalkhttp://en.wikipedia.org/wiki/Marlhttp://en.wikipedia.org/wiki/Clayhttp://en.wikipedia.org/wiki/Sedimenthttp://en.wikipedia.org/wiki/Fossil


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Foraminiferans(forams for short) are single-celled protists with shells. Their shells are also referred toas tests because in some forms the protoplasm covers the exterior of the shell. The

shells are commonly divided into chambers which are added during growth, though thesimplest forms are open tubes or hollow spheres. Depending on the species, the shell

may be made of organic compounds, sand grains and other particles cemented

together, or crystalline calcite.
http://www.ucmp.berkeley.edu/alllife/eukaryotasy.htmlhttp://upload.wikimedia.org/wikipedia/en/0/06/Live_Ammonia_tepida.jpghttp://www.ucmp.berkeley.edu/alllife/eukaryotasy.html


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Foraminifera


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Graptolites


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Magnetostratigraphy

is a chronostratigraphic technique used to date sedimentary and

volcanic stratigraphic sections.

It is based on natural residual magnetization of the rocks asit was in the moment of its hardening.

During earth history, the magnetic poles changed itslocations.

Under heating till Curie point or appearence of intrusions,remagnetization occurs.


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Measurements of the magnetic inclination is rocks show where they were located in relation to the

N-S direction and the position in relation to the magnetic poles. This can be used to restore the

continents to past positions, i.e. before continental drift separated them like Africa and S. America

above.


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Absolute geochronology

Radiometry dating : U-Th-Pb, Pb, Rb-Str, K-Ar, Sa-Ne,C.


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Absolute time measurement

Radioactive materials decay at fixed rates. Half lives range between seconds and billions of years.

During the decay the parent material changes into a daughter material by emitting radiation.

By comparing the quantity of parent and daughter material present in a rock it is possible to calculate

the age of the rock.


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Geocronological table


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Geological time scale


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Hadean (4 bln years)

Meteorites bombed Earth, the melting areas appeared

The crust of Moon type (10s m)

Gravitational differentiation of the substances which lead to formation of solid coreand more light silicate crust

Degasation of the mantle which lead to hydrosphere and atmosphere formation

Constant earthquakes because of close location of the Moon

Protoatmosphere (HgO, COs,, , HaS, S02, 1, HBr, HF, Ar, H)

and hydrosphere (cloride without S) appeared the surface of Earth : oceans of liquid rock, boiling sulfur, and impact craters

everywhere

Volcanoes blast off all over the place, and the rain of rocks and asteroids fromspace never ends.

The air is hot, thick, steamy, and full of dust and crud: its made of carbon dioxide

and water vapor, with traces of nitrogen and smelly sulfur compounds. Any rocks that do form from cooling lavas are quickly buried under new lava flows

or blasted to bits by yet another impact.

Some people think that an asteroid as large as the planet Mars hit Earth near thebeginning of the Hadean era, completely smashing and melting Earth and formingthe Moon as part of the "splash!"


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American geologist Dan in 1872 name theancient formation Archean.

Emmons in 1888 y. Distinguished upper partof the ancient formations and named them

Proterozoic. That year Internationalgeological Congres approved suchdivision for Arch and Prz.


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(4-3.5 bln years)

Grey gneises which firstly were found in Canada

(3.5-2.5 bln years)

Greenstone belts (width 1000 km, length 200 km), jespillits

Most water vapor in the air has cooled and condensed to form a global ocean.

Most of the carbon dioxide is gone, having been chemically changed into limestone anddeposited at the bottom of the ocean.

The air is now mostly nitrogen, and the sky is filled with normal clouds and rain.

The lava also is mostly cooled to form the ocean floor.

The interior of Earth is still quite hot and active, as shown by the many erupting volcanoes.The volcanoes form lots of small islands in long chains. The islands are the only land surface.The continents have not formed yet. The islands are carried over the surface of Earth by themovement of rock deep in Earth's interior.

Occasionally the small islands collide with each other to form larger islands. Eventually theselarger islands will collide to form the cores of the continents we know today.

By the end of Archean, the crust of 30-40 km thickness existed

The appearance of life (seaweeds are found in Australia)

Mineral resources:Fe, Mn, Au, NiTi, Co, , Li, Be. In green stone belts Fe, Au, u, PbZnSb, Cr,Ni


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Distribution of grey gneises1-grey gneises, 2 - archean platform, 3 - early proterozoic

mobile belts


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Proterozoic EraColumbia and Rodinia supercontinents

Columbia (also known as Nuna and, more recently, Hudsonland or Hudsonia) is the name ofone of the Earth's posited supercontinents. It existed approximately 1.8 to 1.5 billion years (Ga)ago in the PaleoproterozoicEra, making it the oldest hypothesized continent. It consisted of theproto-cratons that made up the former continents of Laurentia, Baltica, Ukraine, Amazonia,Australia, and possibly Siberia, North China and Kalahari as well. The existence of Columbia isbased upon paleomagnetic data .The rifted fragments formed the supercontinent Rodinia about500 million years later.

Rodinia (from the Russian, or "motherland") refers to the oldest known supercontinents,which contained most or all of Earth's then-current landmass.

Geologic evidence suggests that Rodinia formed and broke apart in the Neoproterozoic, probablyexisting as a single continent from 1 billion years ago until it began to rift into eight smallercontinents about 800 million years ago.[1] It is thought to have been largely responsible for thecold climate of the Neoproterozoic era.

Rodinia's landmass was probably centered south of the equator. Because Earth was at that timeexperiencing the Cryogenian period of glaciation, and temperatures were at least as cool as

today, substantial areas of Rodinia may have been covered by glaciers or the southern polar icecap. The interior of the continent, being so distant from the temperature-moderating effects of theocean, was probably seasonally extremely cold (see continental climate). It was surrounded bythe superocean geologists are calling Mirovia (from mir, the Russian word for "globe").
http://en.wikipedia.org/wiki/Supercontinenthttp://en.wikipedia.org/wiki/Paleoproterozoichttp://en.wikipedia.org/wiki/Era_%28geology%29http://en.wikipedia.org/wiki/Cratonhttp://en.wikipedia.org/wiki/Laurentiahttp://en.wikipedia.org/wiki/Balticahttp://en.wikipedia.org/wiki/Ukrainehttp://en.wikipedia.org/wiki/Amazoniahttp://en.wikipedia.org/wiki/Australiahttp://en.wikipedia.org/wiki/Paleomagnetismhttp://en.wikipedia.org/wiki/Paleomagnetismhttp://en.wikipedia.org/wiki/Siberiahttp://en.wikipedia.org/wiki/North_Chinahttp://en.wikipedia.org/wiki/Kalaharihttp://en.wikipedia.org/wiki/Rodiniahttp://en.wikipedia.org/wiki/Paleomagnetismhttp://en.wikipedia.org/wiki/Rodiniahttp://en.wikipedia.org/wiki/Russian_languagehttp://en.wikipedia.org/wiki/Supercontinenthttp://en.wikipedia.org/wiki/Neoproterozoichttp://en.wikipedia.org/wiki/Snowball_Earthhttp://en.wikipedia.org/wiki/Equatorhttp://en.wikipedia.org/wiki/Cryogenianhttp://en.wikipedia.org/wiki/Glaciationhttp://en.wikipedia.org/wiki/Glacierhttp://en.wikipedia.org/wiki/Polar_ice_caphttp://en.wikipedia.org/wiki/Polar_ice_caphttp://en.wikipedia.org/wiki/Continental_climatehttp://en.wikipedia.org/wiki/Continental_climatehttp://en.wikipedia.org/wiki/Superoceanhttp://en.wikipedia.org/wiki/Miroviahttp://en.wikipedia.org/wiki/Mirhttp://en.wikipedia.org/wiki/Mirhttp://en.wikipedia.org/wiki/Miroviahttp://en.wikipedia.org/wiki/Superoceanhttp://en.wikipedia.org/wiki/Continental_climatehttp://en.wikipedia.org/wiki/Polar_ice_caphttp://en.wikipedia.org/wiki/Polar_ice_caphttp://en.wikipedia.org/wiki/Glacierhttp://en.wikipedia.org/wiki/Glaciationhttp://en.wikipedia.org/wiki/Cryogenianhttp://en.wikipedia.org/wiki/Equatorhttp://en.wikipedia.org/wiki/Snowball_Earthhttp://en.wikipedia.org/wiki/Neoproterozoichttp://en.wikipedia.org/wiki/Supercontinenthttp://en.wikipedia.org/wiki/Russian_languagehttp://en.wikipedia.org/wiki/Rodiniahttp://en.wikipedia.org/wiki/Paleomagnetismhttp://en.wikipedia.org/wiki/Kalaharihttp://en.wikipedia.org/wiki/North_Chinahttp://en.wikipedia.org/wiki/Siberiahttp://en.wikipedia.org/wiki/Australiahttp://en.wikipedia.org/wiki/Amazoniahttp://en.wikipedia.org/wiki/Ukrainehttp://en.wikipedia.org/wiki/Balticahttp://en.wikipedia.org/wiki/Laurentiahttp://en.wikipedia.org/wiki/Cratonhttp://en.wikipedia.org/wiki/Era_%28geology%29http://en.wikipedia.org/wiki/Paleoproterozoichttp://en.wikipedia.org/wiki/Supercontinent


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Stromatolithes (fossils of cyanobacteria) were widely spread which is important for strartigraphy.

The Oxygen Catastrophe was a massive environmental change believed to have

happened at the beginning of the Paleoproterozoicera, about 2.4 billion years ago. It is

also called the Oxygen Crisis, Oxygen Revolution or The Great Oxidation.

Eucariots who began to use oxigen breathing

Cyanobionta-3.5 bln-first who used photosynthesis

- pink, yellow, green, black- single, group of cells or colonies covered with biofilm- depth maximum 150 m-very stable to environmental change andcontamination
http://en.wikipedia.org/wiki/Paleoproterozoichttp://en.wikipedia.org/wiki/Erahttp://upload.wikimedia.org/wikipedia/commons/6/64/Anabaena_sperica.jpeghttp://en.wikipedia.org/wiki/Erahttp://en.wikipedia.org/wiki/Paleoproterozoic


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Stromatolithes


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Proterozoic

the age 2.5-2.6 bln y The speed of sedimentary deposition was slow In Africa 2 protoplatforms existed- Congo and Kalahari. Bushveld appeared which is under studying during 70 years and

Birrim belt (Golden coast)

Pangea was disintegrated and then integrated again (Pangea I-Megagea) Mantle was enriched with SiO2 Evaporites appeared and glaciers depositions Red rocks which indicate presence of O2 in the atmosphere Huge accumulation of Fe, Co, Mn, Cu, U, Au, diamonds Point of Paster 0.1% of O2 compared with modern content of O2 850 mln Pangea I was disintegrated at Laurasia and Gondvana


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Because of the absence of the plants, the conclusions were madebased on spreading of sedimantary rocks. Dolomites andlimestones indicate that the climate was marine and very warm.

Isotopes of H2 and O2 in the flints of carbonate rocks show thetemperature of 40-50 C.

The presence of red rocks indicates that in some parts the climatewas arid.

Tillites glaciars 750720 mln y and 680650 mln y. Fe

Mineral resources: Cu, Ag, Au, o, Ni, Be, U, Ta, W, Zn, Ti, Va, Cd,Ge, diamonds

Copper Belt : width 50 55 km, length more than 300 km in Zaire

and more than 200 km in Zambia. The biggest U mine Shinkolobvein Zaire.

Oil and gas in Eastern Siberia.

Vend/Ediacaran


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Vend/Ediacaran

650 to 540 million years agomacroscopic fossils of soft-bodied organisms can be found in a

few localities around the world, confirming Darwin's expectations. Only in 1952 Sokolov

separated in Baltic rock the intermediate layer between Criptozoic and Cambrian which he named

VendEdiacarian fauna was of a glaciars periodgigantism, worms and gelly-fish till 1 m size.

Vendian localities:

Ediacara HillsFossils of some of the oldest known animals were discovered at this Australian

locality in 1946.

Mistaken Point, NewfoundlandMysterious fossils from the coast of Newfoundland.

White SeaLocated on the northern coast of Russia.
http://www.ucmp.berkeley.edu/vendian/ediacara.htmlhttp://www.ucmp.berkeley.edu/vendian/mistaken.htmlhttp://www.ucmp.berkeley.edu/vendian/whitesea.htmlhttp://www.ucmp.berkeley.edu/vendian/whitesea.htmlhttp://www.ucmp.berkeley.edu/vendian/mistaken.htmlhttp://www.ucmp.berkeley.edu/vendian/ediacara.html


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Fanerozoic


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FanerozoicPaleozoic, Mezozoic, Kainozoic

Pz - 1838 Sedjvic and Mz, Kz - in 1840 Phillips

1930 . s. Chedvic Fanerozoic, Pr and Archean Criptozoic.

540 mln-230 mln 6 periods: Cambrian , Ordovician ,Silurian ,Devonian ,CarbonPermian.

Animals with spinal.
http://en.wikipedia.org/wiki/Cambrianhttp://en.wikipedia.org/wiki/Ordovicianhttp://en.wikipedia.org/wiki/Silurianhttp://en.wikipedia.org/wiki/Devonianhttp://en.wikipedia.org/wiki/Permianhttp://en.wikipedia.org/wiki/Permianhttp://en.wikipedia.org/wiki/Devonianhttp://en.wikipedia.org/wiki/Silurianhttp://en.wikipedia.org/wiki/Ordovicianhttp://en.wikipedia.org/wiki/Cambrian


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Green-blue seaweeds with the stromatolites and onkolithes the

traces of their activity, other seaweeds Sudden kingdom of all kinds of animals. Cambrian fuana had no

predecessors. The highest speed of evolution needed for that.

How to explain the ability to make skeleton and such a rapidevolution?

1) explosion of super-nova

2) radiation appearance of ozon screen


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Trilobites


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Glaciers existed everywhere withthe zones of very hot climate

decrease of CO2 in atmosphere


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VII , .

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hystorical geology

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