 |
| Titel |
The earliest Cambrian record of animals and ocean geochemical change |
| VerfasserIn |
Adam Maloof, Susannah M. Porter, John L. Moore, Jahan Ramezani, Samuel A. Bowring, Frank O. Dudas, John A. Higgins, David A. Fike, Michael P. Eddy |
| Konferenz |
EGU General Assembly 2011
|
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 13 (2011) |
| Datensatznummer |
250046385
|
|
|
|
|
|
| Zusammenfassung |
| The earliest Cambrian is characterized by the diversification of skeletal animals and deep
animal burrows, the first appearance of metazoan reefs, and some of the largest amplitude
δ13C variability in the Phanerozoic (comparable in amplitude even to Neoproterozoic
excursions). The δ13C oscillations form the backbone of many earliest Cambrian intra- and
inter-continental correlations constructed to address questions about timing and geographic
patterns in animal evolution. Furthermore, the δ13C data has been used to model the behavior
of the earliest Cambrian carbon cycle. However, recent challenges to the validity of
carbon-isotope data from carbonate rocks as a primary record of the global inorganic
carbon reservoir cast doubt on these correlations and carbon cycle models. We
discuss sedimentological, U-Pb geochronological, and stable isotopic data from
Morocco, Siberia, Mongolia and China to test competing models for the origin of
earliest Cambrian δ13C variability. In particular, we evaluate burial diagenesis and
Holocene-Bahamas-style meteoric diagenesis models for negative δ13C excursions, and
compare early Cambrian δ13C behavior to that in the Neoproterozoic and Cenozoic. |
|
|
|
|
|
|