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Université de Fribourg

Scanning electron microscope images of uncoated microfossils: applications, perspectives and limitations

Spezzaferri, Silvia ; Neururer, Christoph ; Pirkenseer, Claudius ; Grobéty, Bernard

In: The Journal of Foraminiferal Research, 2007, vol. 37, no. 3, p. 270-276

We present a recently developed method using a field emission scanning electron microscope (FEG) to view and photograph microfossil specimens that are not coated by conductive material. The FEG microscope provides high electron flux and offers the option to capture images at low beam voltage. Balancing incident energy with absorbed energy from the detector leads to charge-free images of...

Université de Fribourg

Dicarinella imbricata (Mornod 1949): First SEM documentation of the lost holotype and foraminiferal assemblage from the type horizon (Upper Cretaceous, Switzerland)

Caron, Michèle ; Spezzaferri, Silvia

In: Eclogae Geologicae Helvetiae, 2006, vol. 99, no. 3, p. 295-299

The foraminifer species Dicarinella imbricata, from the Upper Cretaceous of Switzerland, was established in 1949 by L. Mornod. The holotype was figured only by Mornod’s drawings and the specimen was never made available. As the holotype was missing since a long time, it was considered as lost and a neotype was established. However, the holotype was recently found.We present here the first...

Université de Fribourg

Scanning electron microscope documentation of the lost holotypes of Mornod, 1949: Thalmanninella reicheli and Rotalipora montsalvensis

Caron, Michèle ; Spezzaferri, Silvia

In: The Journal of Foraminiferal Research, 2006, vol. 36, no. 4, p. 374-378

The species Globotruncana (Rotalipora) reicheli and Gobotruncana (Rotalipora) montsalvensis, were established in 1949 by Mornod. The two holotypes were figured only by drawings and the specimens were never made publicly available. Since their first description, these two species have acquired great importance as biostratigraphic markers. However, holotypes had been considered as...

Université de Fribourg

Third-order depositional sequences reflecting Milankovitch cyclicity

Strasser, André ; Hillgärtner, Heiko ; Hug, Wolfgang ; Pittet, Bernard

In: Terra Nova, 2000, vol. 12(6), p. 303

The origin of third-order depositional sequences remains debatable, and in many cases it is not clear whether they were controlled by tectonic activity and/or by eustatic sea-level changes. In Oxfordian and Berriasian-Valanginian carbonate-dominated sections of Switzerland, France, Germany and Spain, high-resolution sequence-stratigraphic and cyclostratigraphic analyses show that the sedimentary...