E-viri
Recenzirano
-
Stueeken, Eva E
Geochimica et cosmochimica acta, 11/2013, Letnik: 120Journal Article
Nitrogen limitation caused by trace metal scarcity under euxinic ocean conditions has been proposed as an explanation for the delayed radiation of eukaryotes until at least the late Mesoproterozoic. However, evidence for how the nitrogen cycle was operating during the middle Precambrian is, so far, rare. More specifically, it is unknown which steps in the biogeochemical nitrogen cycle, e.g. nitrogen fixation, nitrification or ammonification, were rate-limiting and thus controlling microbial community structures. The Mesoproterozoic Belt Supergroup in western Montana hosts a variety of facies ranging from shallow to deep water and thus offers the opportunity to address this issue. Bulk δ15N values show a clear trend from −1‰ in the deepest part of the basin to +5‰ along basin margins, which suggests that coastal areas were sufficiently oxygenated for aerobic nitrogen cycling. The total fractionation of carbon isotopes between carbonate and organic carbon (Δ13C) increases from 20‰ to 32‰ in the same direction, possibly indicating an ecological response to redox stratification and nitrogen speciation. Evidence from the Belt Supergroup is thus consistent with the idea that nutrient availability may have restricted early eukaryotic organisms to a narrow range of habitats, which thus prevented a global rise to ecological dominance until concentrations of fixed nitrogen increased in the global open ocean.
Avtor
![loading ... loading ...](themes/default/img/ajax-loading.gif)
Vnos na polico
Trajna povezava
- URL:
Faktor vpliva
Dostop do baze podatkov JCR je dovoljen samo uporabnikom iz Slovenije. Vaš trenutni IP-naslov ni na seznamu dovoljenih za dostop, zato je potrebna avtentikacija z ustreznim računom AAI.
Leto | Faktor vpliva | Izdaja | Kategorija | Razvrstitev | ||||
---|---|---|---|---|---|---|---|---|
JCR | SNIP | JCR | SNIP | JCR | SNIP | JCR | SNIP |
Baze podatkov, v katerih je revija indeksirana
Ime baze podatkov | Področje | Leto |
---|
Povezave do osebnih bibliografij avtorjev | Povezave do podatkov o raziskovalcih v sistemu SICRIS |
---|
Vir: Osebne bibliografije
in: SICRIS
To gradivo vam je dostopno v celotnem besedilu. Če kljub temu želite naročiti gradivo, kliknite gumb Nadaljuj.