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Formed close to the K-Pg boundary, the Boltysh meteorite crater, Ukraine, preserves >400 m of lacustrine sedimentary rocks that include a record of the early Danian Dan-C2 hyperthermal event. Abundant pollen, spores and algae recovered from these sediments have yielded a cyclic record of plant ecology change paced by c. 21 kyr orbital precession cycles. New, higher resolution sampling across the inception of the Dan-C2 hyperthermal event has identified oscillations in vegetation community ecology at sub-orbital periods of c. 2 kyr, c. 200 years and c. 11 years. These are consistent with possible Hallstatt, DeVreis-Suess and Schwabe solar cycles, respectively. Rapid regime shift from savanna to a mesic forest ecosystem was paced by c. 21 kyr precession, with the shift probably occurring in <200 years. Prior to regime shift, c. 2 kyr (i.e. possible Hallstatt) oscillations between mesic- and winterwet-dominated plant communities increased in intensity, suggestive of ecological flickering. [ABSTRACT FROM AUTHOR]

Sedimentary rocks filling the Boltysh meteorite crater preserve an expanded record of post Cretaceous-Palaeogene (K/Pg) event vegetation destruction and subsequent floral recolonization. A post-destruction barren zone is succeeded by a fern spore spike recording the initial recovery vegetation. The Boltysh fern spore spike is divisible into two phases. Phase 1 is characterized by low abundances of fern spores, whereas the overlying Phase 2 has high fern spore abundances and contains common palm pollen. Comparison of the Boltysh Phase 2 fern spore spike with other palynological records shows strong similarities to the immediately post K/Pg boundary record of the Western Interior, North America. Variation in the composition of the Boltysh palynofloras has been used to define four moisture availability cycles between the K/Pg boundary and the Dan-C2 negative carbon isotope excursion, a period of some 300 kyr. Early post K/Pg event vegetation community recovery followed a common seral successional pathway at rates seen in large igneous provinces, although enhanced by high moisture availability. Continued succession to the first true swamp community was at a considerably slower tempo. The post K/Pg event vegetation recovery was therefore retarded by lack of moisture availability, extending the apparent period of recovery. [ABSTRACT FROM AUTHOR]