Decapod crustaceans from the Middle Jurassic Opalinus Clay of northern Switzerland, with comments on crustacean taphonomy

2004 ◽  
Vol 97 (3) ◽  
pp. 381-392 ◽  
Author(s):  
Walter Etter
2020 ◽  
Vol 139 (1) ◽  
Author(s):  
Christian Klug ◽  
Walter Etter ◽  
René Hoffmann ◽  
Dirk Fuchs ◽  
Kenneth De Baets

AbstractAlthough belemnite rostra can be quite abundant in Jurassic and Cretaceous strata, the record of belemnite jaws was limited to a few specimens from Germany and Russia. Here, we describe and figure three cephalopod jaws from the Middle Jurassic Opalinus Clay of northern Switzerland. Although flattened, the carbonaceous fossils display enough morphological information to rule out an ammonoid, nautiloid or octobrachian origin of the two larger jaws. Their similarities to belemnite jaws from Germany and Russia conforms with our interpretation of these specimens as belemnite jaws. Based on their rather large size, we tentatively assign these two jaws to the megateuthidid Acrocoelites conoideus. The third jaw is a rather small upper jaw of an ammonoid. Since Leioceras opalinum is by far the most common ammonite in this unit in northern Switzerland, we tentatively suggest that the upper jaw belongs to this species.


2003 ◽  
Vol 807 ◽  
Author(s):  
L. H. Johnson ◽  
J. W. Schneider ◽  
Piet Zuidema ◽  
P. Gribi ◽  
G. Mayer ◽  
...  

ABSTRACTNagra (the Swiss National Cooperative for the Disposal of Radioactive Waste) has completed a study to determine the suitability of Opalinus Clay as a host rock for a repository for spent fuel (SF), high-level waste from reprocessing (HLW) and long-livedintermediate-level waste (ILW). The proposed siting area is in the Zürcher Weinland region of Northern Switzerland. A repository at this site is shown to provide sufficient safety for a spectrum of assessment cases that is broad enough to cover all reasonable possibilities for the evolution of the system. Furthermore, the system is robust; i.e. remaining uncertainties do not put safety in question.


1994 ◽  
Vol 353 ◽  
Author(s):  
C. McCombie ◽  
I.G. McKinley ◽  
A. Lambert ◽  
M. Thury ◽  
P. Birkhäuser

AbstractRegional characterisation studies of two potential host rocks for a HLW repository - the crystalline basement and the Opalinus clay of Northern Switzerland - have now been completed and documented. Application is now proceeding for the legally required federal, cantonal and communal drilling permits to initiate parallel local investigations in both these formations. The decision to continue with work in both formations is a departure from previously published plans which is intended to maximise the probability that the next major milestone in the HLW programme - demonstrating the feasibility of siting for a deep geological repository in Switzerland - can be reached by the year 2000. This paper reviews the current status of the Swiss HLW programme and outlines the planned “Phase II” site characterisation of the two chosen sites.


2003 ◽  
Vol 807 ◽  
Author(s):  
Bernhard Schwyn ◽  
Paul Wersin

ABSTRACTChemical retention of radionuclides in the near field and in the host rock is an important safety pillar within the Swiss concept for a radioactive waste repository. Geochemical databases for solubility limits in cement and bentonite porewater and sorption / diffusion in cement, compacted bentonite and Opalinus Clay were compiled for use in safety assessment calculations. The databases are presented for selected safety-relevant radioelements. In contrast to earlier safety assessment studies Kd values were not truncated at 5 m3 kg−1 and values well above 10 m3 kg−1 (e.g. for actinides) are reported.


Sign in / Sign up

Export Citation Format

Share Document