Mochras borehole revisited: a new global standard for Early Jurassic earth history

The Early Jurassic epoch was a time of extreme environmental change: there are well-documented examples of rapid transitions from cold, or even glacial, climates to super greenhouse events, the latter characterized worldwide by hugely enhanced organic carbon burial, multiple large isotopic anomalies, global sea-level change, and mass extinction (Price, 1999; Hesselbo et al., 2000; Jenkyns, 2010; Korte and Hesselbo, 2011). These icehouse–greenhouse events not only reflect changes in the global climate system but are also thought to have had significant influence on the evolution of Jurassic marine biota (e.g. van de Schootbrugge et al., 2005; Fraguas et al., 2012). Furthermore, the events may serve as analogues for present-day and future environmental transitions

Cyclostratigraphy and astrochronology

The Milankovitch theory that quasi-periodic oscillations in the Earth-Sun position have induced significant 104-106 year variations in the Earth’s stratigraphic record of climate is widely acknowledged. This chapter summarizes the Earth’s astronomical parameters, the nature of astronomically forced solar radiation, fossil astronomical signals in the stratigraphic record, and the use of these signals in calibrating geologic time

Cyclostratigraphy and astrochronology

The Milankovitch theory that quasi-periodic oscillations in the Earth-Sun position have induced significant 104-106 year variations in the Earth’s stratigraphic record of climate is widely acknowledged. This chapter summarizes the Earth’s astronomical parameters, the nature of astronomically forced solar radiation, fossil astronomical signals in the stratigraphic record, and the use of these signals in calibrating geologic time

Große Streubreite der Messergebnisse bei der Bestimmung des Prostataspezifischen Antigens (PSA) bei verschiedenen Assays trotz WHO-Standardisierung

The Milankovitch theory of climate change is widely accepted, but the registration of the climate changes in the stratigraphic record and their use in building high-resolution astronomically tuned timescales has been disputed due to the complex and fragmentary nature of the stratigraphic record. However, results of time series analysis and consistency with independent magnetobiostratigraphic and/or radio-isotopic age models show that Milankovitch cycles are recorded not only in deep marine and lacustrine successions, but also in ice cores and speleothems, and in eolian and fluvial successions. Integrated stratigraphic studies further provide evidence for continuous sedimentation at Milankovitch time scales (104 years up to 106 years). This combined approach also shows that strict application of statistical confidence limits in spectral analysis to verify astronomical forcing in climate proxy records is not fully justified and may lead to false negatives. This is in contrast to recent claims that failure to apply strict statistical standards can lead to false positives in the search for periodic signals. Finally, and contrary to the argument that changes in insolation are too small to effect significant climate change, seasonal insolation variations resulting from orbital extremes can be significant (20% and more) and, as shown by climate modelling, generate large climate changes that can be expected to leave a marked imprint in the stratigraphic record. The tuning of long and continuous cyclic successions now underlies the standard geological time scale for much of the Cenozoic and also for extended intervals of the Mesozoic. Such successions have to be taken into account to fully comprehend the (cyclic) nature of the stratigraphic record