High-resolution sequence interpretation of epeiric shelf carbonates by means of palynofacies analysis: An example from the Germanic Triassic (Lower Muschelkalk, Anisian) of East Thuringia, Germany

The Steudnitz quarry (East Thuringia, Germany) exposes the entire Lower Muschelkalk (Middle Triassic, Anisian) with a thickness of 103 m. In this paper, a primarily palynofacies-based sequence-stratigraphical interpretation supported by lithological investigations is proposed. Palynofacies of the sampled carbonate rocks is dominated by land-derived phytoclasts and pollen grains. Spores are quite rare. Marine plankton reaches its maximum abundance in an interval around the ThuringianSpiriferina-bed and the Terebratel-beds. In accordance with lithological features, this interval may be interpreted as a third-order maximum-flooding zone. Two different third-order interpretations are presented and discussed. Third-order sequences and parasequence sets can be identified by use of palynofacies analysis. Furthermore, palynofacies analysis provides an additional possibility of recognizing partly eroded or originally incomplete cycles (‘missed beats’). In some cases, a resolution down to the level of parasequences is possible. High-resolution palynofacies analysis is a powerful new tool in sedimentology but should always be combined with lithofacies interpretation. It provides very useful, additional information for high-resolution sequence analysis and palaeoenvironmental interpretation. Being a rather young method, high-resolution palynofacies analysis still shows some calibration problems with classical methods. However, these should be solvable by further research

New data from the J/K boundary time interval (Clue de Taulanne section, SE France): implications for western Tethys palaeoclimatic and paleoceanographic scenarios

In the western Tethyan realm, the Jurassic/Cretaceous (J/K) boundary interval is marked by considerable palaeoclimatic and paleoceanocgraphic changes. It is also characterized by a calcareous nannofossil speciation event and by the first occurrence of calpionellids. The Clue de Taulanne section (SE France) exposes Upper Jurassic to Lower Cretaceous carbonate rocks that were deposited in a deep shelf setting on the north-western margin of the Alpine Tethys. A multidisciplinary approach, comprising lithostratigraphy, carbonate sedimentology, sequence stratigraphy, biostratigraphy (ammonites, calpionellids, nannofossils and pelagic microfossils), clay mineral analysis, magnetic susceptibility, and carbon-isotope stratigraphy is presented. The studied rocks cover a time interval from the Late Kimmerigian to the Late Berriasian. Preliminary clay-mineral and magnetic susceptibility data support a postulated dry phase during the Tithonian and a return to more humid conditions during the Berriasian (Rameil, 2005; Schnyder, 2003). Carbon-isotope analysis reveals a negative stratigraphic trend that correlates well with established curves. On the basis of a robust bio- and chemostratigraphy, correlations with various sections in platform and basinal settings on the northern and southern margins of the western Tethys (Rameil, 2005; Schnyder, 2003) are proposed. Within this stratigraphic framework changes in palaeoclimate, palaeoceanography, sedimentation patterns, plankton radiation and calcification events, and their potential interconnections are discussed

Novel CD28-Responsive Enhancer Activated by CREB/ATF and AP-1 Families in the Human Interleukin-2 Receptor α-Chain Locus

The interaction of interleukin-2 (IL-2) with its receptor (IL-2R) critically regulates the T-cell immune response, and the α chain CD25/IL-2Rα is required for the formation of the high-affinity receptor. Tissue-specific, inducible expression of the IL-2Rα gene is regulated by at least three positive regulatory regions (PRRI, PRRII, and PRRIII), but none responded to CD28 engagement in gene reporter assays although CD28 costimulation strongly amplifies IL-2Rα gene transcription. By DNase I hypersensitivity analysis, we have identified a novel TCR-CD3- and CD28-responsive enhancer (CD28rE) located 8.5 kb 5′ of the IL-2Rα gene. PRRIV/CD28rE contains a functional CRE/TRE element required for CD28 signaling. The T-cell-specific, CD28-responsive expression of the IL-2Rα gene appears controlled through PRRIV/CD28rE by cooperation of CREB/ATF and AP-1 family transcription factors