Cretaceous-Tertiary profile, rhythmic deposition, and geomagnetic polarity reversals of marine sediments near Bjala, Bulgaria

External forcing of the geomagnetic field? Implications for the cosmic ray flux—climate variability

“…A very interesting data-set showing a clear relation between palaeomagnetic ÿeld reversals and carbonate content of Palaeogene limestones was published by Preisinger et al (2002) without, however, discussing implications for the geomagnetic ÿeld-climate link. In this study, a 1:5 Ma duration section of chalk-marl Milankovitch precession cycles contains 4 geomagnetic reversals each of which is related to an extreme minimum in carbonate content.…”

“…In the ÿrst part of the paper the few studies available so far on a geomagnetic reversal-climate relation in the Quaternary are summarised and interpreted. Tertiary sedimentary cycles from the lower Danian section Bjala, Bulgaria (Preisinger et al, 2002) are discussed. The compilation of data on the geomagnetic history, galactic motion of the solar system and geological characteristics of the Ordovician through Recent (Fig.…”

Biogreigites (Fe3S4) in sea water sediments and their paleohydrological applications

“…They were built after the impact of a meteorite in Chicxulub (Mexico) as a consequence of the sulfuric acid rain [3]. In sediments from the Black, the Marmara, and the Caspian Sea, we have also discovered clusters of twinned nanocrystalline ferrimagnetic greigites (biogreigites) dated from the Quaternary.…”

“…The released plume produced a huge amount of H 2 SO 4 , supercritical CO 2 , and H 2 O in the stratosphere which was further spread over the world [3]. The following sulfuric acid rain caused in the Tethis a spontaneous increase of the S content.…”

Glacioeustatic sea level fall marking the base of supercycle TA-1 at 66.5Ma recorded by the kaolinization of the Whitemud Formation and the Colgate Member of the Fox Hills Formation

“…Along Hell Creek Park road, the total thickness of 29r is 50 m. The duration of magnetochron 29r has been closely determined by astronomical dating to be 603,000-608,000 years (D'Hondt et al, 1996;Preisinger et al, 2002) producing an ACSAR of 83 m/m.y. The thickness of 30r is about 10 m, yielding a somewhat less precise ACSAR of w100 m/m.y.…”