Rodinium
The Rodinium is the fourth period within the eon Proterozoic and the only period in the era Mesoproterozoic . It follows the period of columbium and in turn is superseded by the period of cryogenium . The rodinium lasted 930 million years and fills the period from 1780 million years BP to 850 million years BP. It replaces the earlier Statherium , Calymmium , Ectasium , Stenium and Tonium .
designation
The Rodinium, English Rodinian , was derived from the supercontinent Rodinia , which accreted BP between 1300 and 900 million years ago. Rodinia in turn comes from the Russian Родить, rodítj , meaning to give birth or from Родина, ródina , which means motherland, homeland .
Redefinition of the Precambrian Periods
In the course of moving away from period boundaries determined purely by radiometry, the GSSP principle should now be applied as far as possible in the Precambrian, according to Gradstein et al. (2012) . The periods are thus defined on the basis of significant geological events and no longer on arbitrary, radiometric ages.
Definition of the rodinium
The rodinium begins with the first appearance of sulphidic , reducing, marine deposits around 1780 million years BP. A GSSP has not yet been established for the lower bound, but it could be defined with the first appearance of acritars or the first huge sulphide deposits. There is also no GSSP for the upper limit of the rodinium at 850 million years BP, but this could be characterized by the first occurrence of metazoa or by δ 13 C or strontium anomalies.
meaning
Despite the disintegration of the supercontinent Columbia and the subsequent formation of Rodinia in the period 1300 to 900 million years BP, the extremely long, almost one billion years long period of the Rodinian is characterized by a pronounced stability of the essential, biologically relevant isotope systems (for example, the δ 13 C-values in carbonates only slightly around 0 ‰).
The ribbon ores , which were only to reappear to a limited extent around 800 million years BP, disappeared again in it. Significantly, no more glaciations can be recorded in the long course of the rodinium . Other outstanding characteristics of this period (ie of the entire Mesoproterozoic) are sulphidic, reducing deep waters and a gradual diversification of the eukaryotes .
In the earth's atmosphere , the oxygen concentrations continued to rise slowly and steadily (up to 8 to 15% of today's value), but the carbon dioxide partial pressures fell, recognizable by the absence of massive siderite deposits from 1800 million years BP. The methane concentrations probably remained high during the Rodinian and warmed the continents of that time as a thin haze. It is possible that laughing gas (N 2 O) also played the role of a greenhouse gas at the time.
The rise in oxygen gave rise to two new types of ore deposits :
- An unconformity -bound uranium deposits , which in particular in 1740 to 800 million years BP Canada and Australia formed.
- So-called SEDEX ores , massive, exhalative, sediment-bound sulphide ores , which mainly deposited between 1800 and 1000 million years BP.
In the case of the world's oceans, Canfield proposes a stratification for the duration of the rodinium (so-called Canfield Ocean ), with an oxygen-rich surface layer and Euxinian , hydrogen-sulphide-rich deep waters. The Canfield model is based on observations such as low sulfate concentrations in seawater (5 to 15% of today's value), sulfide-containing, anoxic deep waters and the formation of massive sulfide deposits. However, the relatively simple Canfield model is not generally accepted, but much more complicated models with lateral and vertical gradients are also being discussed.
The transition from the iron-enriched, oxygen-undersaturated oceans of the Paleoproterozoic to sulphide-containing seas of the Rodinian can be explained on the one hand by the complete precipitation of the available iron, on the other hand by increased oxidative weathering on the continents. As a result of increased erosion activity, sulphates have now been washed into the oceans, which microbes have reduced to sulphides.
Biological evolution
The evolution of living beings experienced a significant diversification of the eukaryotes during the rodinium. The oldest eukaryotic acritars come from the approximately 1800 million year old Changzhougou Formation in the People's Republic of China . Also in China, around 1700 million years old, multicellular organisms were discovered in the Tuanshanzi Formation and Haines (1997) described sedimentary traces in 1750 million year old rocks of northern Australia , which were produced by algae threads .
Grypania spiralis , the oldest known eukaryote, dates back to 2100 million years BP. It still occurs in India, China, and the United States between 1600 and 1450 million years BP. This extremely long distribution time of Grypania was interpreted as evolutionary stagnation, which was supposedly caused by Euxinian deep waters. The low availability of molybdenum , iron and nitrogen is said to have made nitrogen fixation difficult for eukaryotes.
However, macroscopic and microfossil evidence suggests that eukaryotes began to diversify between 1500 and 1400 million years BP. Around 1200 million years BP, in the fossil record, besides eukaryotes, fungal organisms and even microbes can be found on the mainland - which clearly indicates increased oxygen concentrations. In addition, with Bangiomorpha pubescens , a red alga , a sexually reproducing multicellular cell appears for the first time .
Other examples of macroscopic fossils are the so-called pearl necklaces (English string of beads ) encountered from 1500 to 1400 million years BP at several sites. They are likely to be primitive seaweed with anchoring (Metaphyta). Around 1500 million years BP, simple acritarches also appear in the fossil record, which are replaced by much more complex forms between 1200 and 1000 million years BP, which can also be detected on the mainland. The first green algae and heterotrophic eukaryotes develop before the cryogenium has frozen over. Despite the spread of eukaryotes during the rodinium, the evolution-inhibiting effect of the sulphidic Canfield Ocean should not be underestimated.
Geodynamic development
The supercontinent Columbia entered a rift phase with the beginning of the Rodinian and began to break apart from 1600 million years BP. This decay process occurs in the sediments of the Belt-Purcell Supergroup on the western edge of Laurentia , the Chhattisgarh Supergroup on the Mahanadi and the Godavari Supergroup on the Godavari in eastern India , the Telemark Supergroup of the Baltic Shield , the Riphean Aulakogen on the southeastern edge of Siberia , the Kalahari Copper Belt on the northwestern edge of the Kalahari Craton and the Zhaertai Bayan Obo Belt on the northern edge of the North China Craton .
The collapse of Columbia was accompanied by widespread, anorogenic magmatism , which, between 1600 and 1300 million years BP , gave rise to the so-called AMCG sequences ( anorthosite - mangerite - charnockite - granite ) in Laurentia, Baltica , Amazonia and northern China . The decay process ended between 1300 and 1200 million years BP, as the intrusion of mafic gang swarms suggests ( Mackenzie gang swarm around 1270 million years BP, Sudbury gang swarm around 1240 million years BP).
Parallel to the collapse of Columbia, accretions went hand in hand, which for example extended the southeastern edge of Laurentia through the Yavapai mountain formation (1800 to 1690 million years BP) and the Mazatzal mountain formation (1710 to 1620 million years BP). In Australia / Antarctica , the Mawson continent was formed around 1600 million years BP .
stratigraphy
Significant sedimentary basins and geological formations
-
MacArthur Basin in the Northern Territory of Australia - 1870 to 1280 million years BP
- Roper Group - 1492 to 1280 million years BP
- Nathan Group - around 1590 million years old BP
- MacArthur Group - 1710/1670 to 1600 million years BP
- Tawallah Group - 1790 to 1700 million years old BP
- Earaheedy Basin in Western Australia - 1900 to 1650 million years BP
-
Bangemall Basin on the Capricorn Orogen in Western Australia - 1630 to 1300 million years BP
- Edmund Group - 1620 to 1465 million years old BP
-
Vindhya supergroup in northern India - 1721 to 600 million years BP
-
Semri Group - 1721 to 1599 million years BP
- Rohtas Formation - 1601 to 1599 million years BP
- Rampur Shale - 1602 to 1593 million years BP
-
Semri Group - 1721 to 1599 million years BP
-
Chhattisgarh Supergroup in India
- Kharsiya Group -> 900 million years BP
- Raipur Group - until 1007 million years of BP
- Chandarpur Group
- Singhora Group - 1500 to 1420 million years old BP
-
Godavari Supergroup in India - 1685 to 1000 million years BP
- Sullavai Group - around 1000 million years BP
- Penganga Group - approximately 1400 to 1000 million years old BP
- Mulug Group - 1565 to 1400 million years old BP
- Mallampalli Group - 1685 to 1565 million years BP
- Xiong'er Group of the North China Craton - 1800 to 1750 million years ago
-
Changcheng System of North China Craton - 1731 to 1400 million years BP
- Changcheng Group - 1731 to 1600 million years old BP
-
North China Craton Gaoyuzhuang System - 1425 to 1348 million years BP
- Guandi Formation - around 1425 million years BP with stromatolites
- Char Group of the Rguibat Shield ( West Africa Craton ) in Mauritania - around 998 million years BP
- Atur Group of the Rguibat Shield in Mauritania - 890 to 775 million years BP
-
Espinhaço Supergroup of the São Francisco Craton in Brazil - 1800 to 900 million years BP
- Upper Espinhaço Sequence (sinking basin) - 1190 to 900 million years BP
- Middle Espinhaço Sequence (sinking basin) - 1600 to 1380 million years BP
- Lower Espinhaço Sequence (Rift Sequence ) - 1800 to 1680 million years BP
- São João del Rey Basin of the South Brasília Belt - 1539 to 1400 million years BP
- Carandaí Basin of the South Brasília Belt - 1412 to 1186 million years BP
- Andrelândia Basin of the South Brasília Belt - 1061 to about 930 million years BP
- Araí Basin of the North Brasília Belt - 1771 to 1767 million years old BP
- Serra de Mesa Basin of the North Brasília Belt - 1557 to 1299 million years BP
- Paranoá Basin of the North Brasília Belt - 1560 to 1042 million years BP
- Supracrustal series of the Vishnu Basement Rocks in the Grand Canyon - 1750 to 1741 million years BP
- Belt-Purcell Supergroup in Montana - 1500 to 1300 million years BP
-
Grand Canyon Supergroup in Arizona - 1250 to 700/650 million years BP
- Chuar Group - 1000 to 700 million years old BP
-
Unkar Group - 1250 to 1070 million years old BP
- Bass formation - around 1250 million years BP
-
Telemark Supergroup of the Baltic Shield - 1510 to 1100 million years old BP
-
Bandak Group -1155 to 1100 million years BP
- Eidsborg Formation - around 1118 million years BP
- Høydalsmo Group - around 1150 million years old BP
- Oftefjell Group - around 1155 million years BP
- Seljord Group , now Vindeggen Group - 1500 to 1155 million years old BP
- Rjukan Group with Tuddal Formation - around 1510 million years BP
-
Bandak Group -1155 to 1100 million years BP
- Torridonian Supergroup in Scotland - 1200 to 1000 million years old BP
- Moine Supergroup in Scotland - 1000 to 873 million years BP
Geodynamics
Igneous accretion belts
- Yavapai Belt in the Southwest and Central Plains of the United States - 1800 to 1700 million years BP
- Mazatzal Belt south of the Yavapai Belt - 1700 to 1600 million years BP
- Makkovik Belt in Labrador - 1800 to 1700 million years BP
- Labrador Belt in Labrador - 1700 to 1600 million years BP
- Ketilid Belt in South Greenland - 1800 to 1700 million years BP
-
Malin Belt in the British Isles - 1800 to 1700 million years BP with
- Rhinn's Complex on Islay (intrusion age 1782 ± 5 million years BP), Inishtrahull (1779 ± 3 million years BP) and Colonsay
- Trans- Scandinavian magma belt in Scandinavia - 1800 to 1700 million years BP
- Kongsberg-Gotland Belt in Scandinavia - 1700 to 1600 million years BP
- Rio Negro Juruena Belt in Brazil - 1800 to 1550 million years BP
-
Arunta Terran in Australia - 1800 to 1500 million years old BP
- Southwark Granite Sequence (around 1570 million years BP)
- Musgrave Terran in Australia - 1800 to 1500 million years old BP
-
Mount Isa Terran in Queensland - 1800 to 1500 million years BP
- Williams granite (batholith) - 1545 to 1490 million years old BP
- Naraku granite (batholith) - 1545 to 1490 million years old BP
- Georgetown Terran in Queensland - 1800 to 1500 million years old BP
- Coen Terran in Australia - 1800 to 1500 million years BP
- Broken Hill Terran in New South Wales and South Australia - 1800 to 1500 million years old BP
-
Mount Painter Terran in the Flinders Ranges in South Australia with 1575 to 1555 million year old granites
- Mount Neill granite series - around 1575 million years BP
- Moolawatana granite series - 1560 to 1555 million years BP
Orogenesis
- Yapungku orogeny - 1795 to 1760 million years BP. Collision between the Northern Australian Craton and the Western Australian Craton
- Olaria orogeny on the eastern edge of the South Australia craton - 1670 to 1600 million years BP
- Isa orogeny on Mount Isa Terran - around 1600 million years BP
- The following orogenes occurred on the southern edge of the North Australian Craton:
- Strangways orogeny - 1780 to 1730 million years BP
- Argilke orogeny - 1680 to 1650 million years BP
- Chewings orogeny - 1620 to 1580 million years BP
- Yavapai orogeny on the southeastern edge of Laurentia - 1800 to 1690 million years BP
- Mazatzal orogeny on the southeastern edge of Laurentia - 1710 to 1620 million years BP
- Elzevirian Orogeny on the eastern edge of Laurentia - 1240 to 1220 million years BP
- Shawingian Orogeny on the eastern edge of Laurentia - 1190 to 1140 million years BP
- Grenville orogeny on the eastern edge of Laurentia - 1090 to 980 million years BP
- Laxfordian in Scotland - 1790 to 1670 million years BP
Individual evidence
- ^ Felix M. Gradstein et al .: On the Geologic Time Scale . In: Newsletters on Stratigraphy . tape 45/2 , 2012, p. 171-188 .
- ^ Li, ZX et al .: Assembly, configuration and break-up history of Rodinia: a synthesis . In: Precambrian Research . tape 160 , 2008, p. 179-210 .
- ↑ Des Marais, DJ et al .: Carbon isotope evidence for the stepwise oxidation of the Proterozoic environment . In: Nature . tape 359 , 1992, pp. 605-609 .
- ↑ Ohmoto, H. et al .: Evidence from massive siderite beds for a CO 2 rich atmosphere before ~ 1.8 billion years ago . In: Nature . tape 429 , 2004, p. 395-399 .
- ↑ Kasting, JF: Methane and climate during the Precambrian era . In: Precambrian Research . tape 137 , 2005, pp. 119-129 .
- ↑ Buick, R .: Did the Proterozoic 'Canfield Ocean' cause a laughing gas greenhouse? In: Geobiology . tape 5 , 2007, p. 97-100 .
- ↑ Jefferson, CW et al .: Unconformity-associated uranium deposits of the Athabasca Basin, Saskatchewan and Alberta . In: Geological Association of Canada, Special Publication . tape 5 , 2007, p. 273-305 .
- ↑ Pirajno, F .: Hydrothermal Mineral Systems . Springer, Berlin 2009, p. 1250 .
- ↑ Kah, LC et al .: Low marine sulfate and protracted oxygenation of the Proterozoic biosphere . In: Nature . tape 431 , 2004, p. 834-838 .
- ^ Arnold, GL et al: Molybdenum isotope evidence for widespread anoxia in Mid-Proterozoic oceans . In: Science . tape 304 , 2004, p. 87-90 .
- ↑ Pufahl, PK et al .: Does the Paleoproterozoic Animikie Basin record the sulfidic ocean transition? In: Geology . tape 38 , 2010, p. 659-662 .
- ↑ Lamb, DM et al .: Evidence for eukaryotic diversification in the ~ 1800 million-year-old Changzhougou Formation, North China . In: Precambrian Research . tape 173 , 2009, pp. 93-104 .
- ^ Zhu, S. and Chen, H .: Megascopic multicellular organisms from the 1700-million-year-old Tuanshanzi Formation in the Jixian area, North China . In: Science . tape 270 , 1995, pp. 620-622 .
- ↑ Haines, PW: Tool marks from around 1750, northern Australia: evidence for large drifting algal filaments? In: Geology . tape 25 , 1997, pp. 235-238 .
- ↑ Sharma, M. and Shukla, Y .: Taxonomy and affinity of Early Mesoproterozoic megascopic helically coiled and related fossils from the Rohtas Formation, the Vindhyan Supergroup, India . In: Precambrian Research . tape 173 , 2009, pp. 105-122 .
- ↑ Du, R. et al.: Discovery of megafossils in the Gaoyushang Formation of the Changchenian System, Jixian . In: Acta Geological Sinica . tape 2 , 1986, p. 115-120 .
- ↑ Walter, MR et al .: Megascopic algae 1300 million years old from the Belt Supergroup, Montana: a reinterpretation of Walcott's Helminthoidischniter . In: Journal of Paleontology . tape 50 , 1976, p. 872-881 .
- ↑ Glass, JB et al.: Coevolution of metal availability and nitrogen assimilation in Cyanobacteria and algae . In: Geobiology . tape 7 , 2009, p. 100-123 .
- ↑ Parnell, J. et al.: Early oxygenation of the terrestrial environment during the Mesoproterozoic . In: Nature . tape 468 , 2010, p. 290-293 .
- ↑ Nicholas J. Butterfield: Bangiomorpha pubescens n. Gen., N. Sp .: implications for the evolution of sex, multicellularity, and the Mesoproterozoic / Neoproterozoic radiation of eukaryotes . In: Paleobiology . tape 26 (3) . Jacksonville NY 2000, p. 386-404 , doi : 10.1666 / 0094-8373 (2000) 026 <0386: BPNGNS> 2.0.CO; 2 .
- ↑ Martin, DM: Depositional environment and taphonomy of the 'strings of beads': Mesoproterozoic multicellular fossils in the Bangemall Supergroup, Western Australia . In: Australian Journal of Earth Sciences . tape 51 , 2004, p. 555-561 .
- ↑ Knauth, LP and Kennedy, MJ: The late Precambrian greening of the Earth . In: Nature . tape 460 , 2009, pp. 728-732 .
- ↑ Porter, SM: The fossil record of early eukaryote diversification . In: Paleontological Society Papers . tape 10 , 2004, p. 35-50 .
- ↑ Anderson, JL and Morrison, J .: Ilmenite, magnetite and peraluminous Mesoproterozoic anorogenic granites of Laurentia and Baltica . In: Lithos . tape 80 , 2005, pp. 45-60 .
- ^ Karlstrom, K. and Bowring, SA: Early Proterozoic assembly of tectonostratigraphic terranes in southwestern North America . In: Journal of Geology . tape 96 , 1988, pp. 561-576 .
- ^ Payne, JL et al .: Correlations and reconstruction models for the 2500-1500 Ma evolution of the Mawson Continent . In: Reddy, SM et al. Paleoproterozoic Supercontinents and Global Evolution (Ed.): Geological Society of London, Special Publications . tape 323 , 2009, pp. 319-356 .
- ↑ Martin, D. McB. and Thorne, AM: Tectonic setting and basin evolution of the Bangemall Supergroup in the northwestern Capricorn Orogen . In: Precambrian Research . tape 128 , 2004, pp. 385-409 .
- ↑ Chaudhuri, AK et al .: Conflicts in stratigraphic classification of the Puranas of the Pranhita-Godavari Valley: review, recommandations and status of the 'Penganga' sequence . In: Geological Society, London, Memoirs . tape 43 , 2014, p. 165-183 .
- ↑ Guadagnin, F. et al .: Age constraints on crystal-tuff from the Espinhaço Supergroup - Insight into the Paleoproterozoic to Mesoproterozoic basin cycles of the Congo-São Francisco Craton . In: Gondwana Research . tape 27 , 2015, p. 363-376 .
- ↑ Guadagnin, F. and Chemale, F .: Detrital zircon record of the Paleoproterozoic to Mesoproterozoic cratonic basins in the São Francisco Craton . In: Journal of South American Earth Sciences . tape 60 , 2015, p. 104-116 .
- ^ Nigel Woodcock and Rob Strachan: Geological History of Britain and Ireland . Blackwell Science Ltd, Oxford 2000, ISBN 0-632-03656-7 .