Sirius Passet
The Sirius Passet - Faunengemeinschaft is a Cambrian Konservatlagerstätte on Pearyland in the far north of Greenland. The fossils found there are mainly soft-bodied organisms that were deposited in the mud of the deep water in the vicinity of a flat Karbonatbank.
The Sirius Passet - Faunengemeinschaft was after the Sirius Patrol, which is in the north of Greenland to use named. The fossil site is located on the eastern shore of JP Koch Fjord in the lower section of the Buen Formation. It was discovered in 1984 by A. Higgins, an employee of the Grønlands Geologiske Undersøgelse. A preliminary report was in 1987 by Simon Conway Morris, among others published. Following this, in the years 1989, 1991 and 1994, three more expeditions led by JS Peel and Simon Conway Morris of, returned to the reference number and have amassed a collection of about 10 000 fossils.
- 4.1 Notes and references
- 4.2 sources
- 4.3 External links
Stratigraphy and geological framework of general
The 325 meter thick Lower Cambrian Buen Formation overlies with abnormal contact (warping ) the light gray dolomite of Neoproterozoic Portfjeld lineup. In it the Brønlund Fjord Group joins. The Buen Formation belongs to the shelf sediments of the southern Franklin Basin ( North Greenland and Arctic islands of Canada). In its lower part it is mainly dominated by sandy facies, the upper section consists of gray-green clay - and siltstones. To the north of the contemporaneous Polkorridoren Group on (700 meter thick deep-water deposits ) the Buen Formation gradually goes into the deeper Kontinentalhangfazies. During the Ellesmerian orogeny she suffered a weak metamorphism and was overprinted greenschist facies metamorphism.
The Konservatlagerstätte is in dark gray to black shales of the lowermost section in the transition region of the Buen Formation for Polkorridoren group.
The occurrence of the trilobite Buenellus higginsi remarkable correlation with the Laurentide Trilobitenzone Nevadella; the latter is now (521 - 517 million years BP) with the 3rd stage (2nd series) of the Cambrian equated.
Fauna
The Sirius Passet - Faunengemeinschaft was inevitably brought to the Burgess Shale in conjunction, although they probably should be ten to fifteen million years older and of Martin et al (2000) is dated to 518 bis 505 million years BP. This time she comes much closer to lie in the Chengjiang Faunengemeinschaft.
The Faunengemeinschaft has not yet been fully described scientifically, but is becoming apparent that it consists of a relatively limited number of species of arthropods, sponges and rare representatives of other groups. It also contains three highly problematic taxa - Halkieria, Kerygmachela and Pambdelurion - which play a significant role in the debate about the origin of today's animal phyla.
Simon Conway Morris published in early 2008, inter alia, a scientific work on the Sirius Passet - Faunengemeinschaft in the journal Acta Palaeontologica Polonica, in which he describes polychaetes from the tribe of annelids. You carry out: " the tribal allocation of Phragmochaeta is still very vague, but could be basal nature." It should be noted here that in the polychaete fauna of the Burgess Shale in the other sub-and mittelkambrischen Fossil deposits are virtually unknown but quite important. This single find thus considerably expanded our understanding of this group of animals. Unfortunately, the specimens described so far are relatively poor in morphological character traits.
Nearly 6,000 fossil -bearing rock fragments that were selected during the period 1985-2006 were used for their work. Additionally, there are also other fossils leading sites known, however, have not yet been studied in detail.
Fauna ordered by tribes
Master Annelida ( segmented worms )
- Phragmochaeta canicularis
Master Arthropoda ( Arthropods )
- Aaveqaspis inesoni
- Buenaspis forteyi
- Isoxys volucris
- Kiisortoqia soperi
- Paulo terminus spinodorsalis - a crustacean
- Siriocaris trollae
Master Arthropoda - Class Trilobita
- Buenellus higginsi
- Kleptothule rasmusseni
Master Lobopodia ( Lobopoden )
- Hadranax augustus
- Kerygmachela kierkegaardi - a Dinocaride
- Pambdelurion whittingtoni - a Dinocaride
- Tamisiocaris borealis
Root of uncertain assignment
- Halkieria evangelista