The Kambrium began 542 million years ago andended 488 million year ago with the beginning of the Ordoviziums. The period is characterized by „the Kambri explosion “, with which in a geologically short period a great many more-cellular animal species developed, whose fundamental structural drawings kept partial until today.
The ancestors of these animalsoriginate from earth ages before the Kambrium, from which however admits only very few fossils are. Therefore the entire period became - of the emergence of the earth approximately 4.56 billion years ago up to the development of the animal world in the Kambrium - when Präkambrium designates. Today one can this long period also without help of guidance fossils better subdivide (see: geological time scale).
The beginning of the Kambriums nevertheless marks both climatically and biologically a very substantial cut in geologic history, with which also the Äon of the Phanerozoikums began, that large geological section,in that the earth into our time developed.
Table of contents
age and layers
see also in detail into geological time scale
beginning of the Kambriums
long time accepted one the beginning of the Kambriums at approximately 600 million years before the present, with that apparently first occurrenceof fossils. Only in recent time fossils could be found and examined even in older layers. Still before 20 years was years determined the beginning of the Kambriums before 590 to 570 million, with the occurrence of the first Trilobiten and Archaeocyathiden (first sponges with lime skeleton). Through radiometric methods this time was shifted in the last decades ever more near toward present. 542 million years ago a cut in the world-wide distribution carbon - of the isotope C-13 , which accompanies with a fundamental change in the fossil fauna , results. By investigations of Zirkonen in volcanic ash - layers from the early Kambrium in Oman the time of these C-13-Anomalie with an accuracy could be determined by 0.3 million years. It is accepted now as beginning of the Kambriums and thus also the beginning of the earth age (era ) Paläozoikum.
in the first half 19. Century the recent layers of the Kambriums directly the layers Silur confronted, soon came it however to delimitation problems and controversy between the geologists. For these questionable layers the term Ordovizium was coined/shaped later and between Kambriumand Silur pushed in.
As a recent epoch of the Kambriums became end 20. Century the Furongium fixed, designated after an old name of the southChinese province Hunan, which „Lotus means “. The Furongium corresponds to the earlier term „upper Kambrium “. Its first stage is designated the Paibium, after thatLocality Paibi, likewise in the province Hunan. Further stages were not internationally specified yet. The Furongium ends to the Graptolithen Rhabdinopora flabelliforme already below the layer with the Conodonten Iapetognathus fluctivagus as well as and the first occurrence of the Trilobiten Jujuyaspis, guidance fossils, those for the beginning of the Ordoviziumsare characteristic.
This border is characterized by becoming extinct many kinds in the transition to the fauna of the Ordoviziums. Perhaps recently freezing up are to be made responsible for it.
- Furongium (upper Kambrium) (501-488 million years)
- further partitioning internationally yet not specified
- Paibium (beginning forwards501 million years)
- middle Kambrium (513-501 million years)
- lower Kambrium (542-513 million years)
- further partitioning internationally yet specified
- Tommotium (beginning 542 million years ago)
- Furongium (upper Kambrium) (501-488 million years)
Became outdated designations:
- Oil US layers:520-500 millions Years (Int. Map symbol €3)
- Paradox the layers: 550-520 millions Years (Int. Map symbol €2)
- Holmia layers: 585-550 millions Years (international map symbol €1)
the names of these layers refer to Trilobiten.
the before existing supercontinent broke. The south continent Gondwana was because of the South Pole, three larger continents, which correspond today to North America, northeast Europe and Siberia, was islandfulinto near-equator ones. For Central Europe as such existed yet, its parts were not appropriate all in southern latitudes.
climate and atmosphere
at the beginning of the Kambriums seems to have occurred a global heating up. By the melting of the ice the sea level rose considerablyon. The Sauerstoffkonzentration in the atmosphere was lower than today, increased however from the Präkambrium to the Kambrium strongly.
all modern animal trunks were in the Kambrium already available, eddy lots like also forerunners of the vertebrate animals like the Conodonten starting from the middle Kambrium. Since that time are no new animal trunks been added. In the Kambrium many kinds developed for the first time hard skeletons and bowls. This on the one hand avowedly as protection from the first large robbers, who arose also at this time, on the other hand by the large offer of calcium carbonate by a change in the chemical compositionthe sea water. The occurrence of these bowls and skeletons, which kept fossil substantially better than the soft parts, makes explainable, why in the Kambrium suddenly so many animal trunks arise, over whose ancestors nothing admits is. Different Korallen formed the first reefs.
From the Burgess slate inthe Rocky Mountains Canada many well received fossils from the middle Kambrium are well-known, above all Gliederfüsser, Anneliden, Onychophora, Priapuliden beside Trilobiten, sponges and did not classify fossils.
as guidance fossils apply:
outthe plant world are only flat acct tables algae well-known. The sediments were through-rooted few, because there were only few kinds living in the sediment (Bioturbation). Thus the alga lawns and Cyanobakterienmatten could solidify themselves and form by lime deposit Stromatolithen. The country was still perfect also from plantsunbesiedelt.
- Olaf Elicki: As the life „exploded “and a completely new world developed: The Kambrium. Biology in our time 33 (6), S. 380-389 (2003), ISSN 0045-205X.
- Ernst rehearses: Germany in the primeval times, C. Bertelsmann, Munich 1986, ISBN 3-570-1066-x.
- StevenM. Stanley:Historical geology, spectrum academic publishing house, Heidelberg, Berlin 2001, ISBN 3-8274-0569-6