Université de Fribourg

Integrated bio- and cyclostratigraphy of Middle Triassic (Anisian) ramp deposits, NW Bulgaria

Ajdanlijsky, George ; Strasser, André ; Götz, Annette E.

In: Geologica Carpathica, 2019, vol. 70, no. 4, p. 325–354

A cyclostratigraphic interpretation of peritidal to shallow-marine ramp deposits of the early Middle Triassic (Anisian) Opletnya Member exposed in outcrops along the Iskar River gorge, NW Bulgaria, is presented. Based on facies trends and bounding surfaces, depositional sequences of several orders can be identified. New biostratigraphic data provide a time frame of the studied succession with...

Université de Fribourg

Cyclostratigraphy of shallow-marine carbonates – limitations and opportunities

Strasser, André

In: Stratigraphy & Timescales, 2018, vol. 3, p. 151–187

The sedimentary record of ancient shallow-marine carbonate platforms commonly displays a stacking of different facies, which reflects repetitive changes of depositional environments through time. These changes can be induced by external factors such as cyclical changes in climate and/or sea level, but also by internal factors such as lateral migration of sediment bodies and/or changes in the...

Université de Fribourg

The early to middle triassic continental–marine transition of NW Bulgaria: sedimentology, palynology and sequence stratigraphy

Ajdanlijsky, George ; Götz, Annette E. ; Strasser, André

In: Geologica Carpathica, 2018, vol. 69, no. 2, p. 129–148

Sedimentary facies and cycles of the Triassic continental–marine transition of NW Bulgaria are documented in detail from reference sections along the Iskar river gorge between the villages of Tserovo and Opletnya. The depositional environments evolved from anastomosing and meandering river systems in the Petrohan Terrigenous Group to mixed fluvial and tidal settings in the Svidol Formation,...

Université de Fribourg

Carbon- and oxygen-isotope records of palaeoenvironmental and carbonate production changes in shallow-marine carbonates (Kimmeridgian, Swiss Jura)

Colombié, Claude ; Lécuyer, Christophe ; Strasser, André

In: Geological Magazine, 2011, vol. 148, no. 1, p. 133-153

Carbon- and oxygen-isotope ratios are commonly used to correlate shallow- and deep-marine successions. Carbon- and oxygen-isotope analyses were performed on bulk-carbonate samples from two Kimmeridgian sections of the Swiss Jura platform in order to correlate them with biostratigraphically well-dated coeval sections in the adjacent basin. On the platform, a general decrease in δ¹³C and...

Université de Fribourg

High-frequency palaeoenvironmental changes on a shallow carbonate platform during a marine transgression (Late Oxfordian, Swiss Jura Mountains)

Védrine, Stéphanie ; Strasser, André

In: Swiss Journal of Geosciences, 2009, vol. 102, no. 2, p. 247–270

Based on a well-established bio- and sequence-stratigraphic framework, a narrow time window in the Bimammatum ammonite zone (Late Oxfordian) is investigated in six Swiss Jura sections representing a shallow-water carbonate platform. From the detailed facies and microfacies analysis of oncoid-rich (Hauptmumienbank Member) and ooid-rich (Steinebach Member) limestones, a microfacies...