Small-scale cyclic sedimentation in the Early Givetian of the Góry Świętokrzyskie Mountains: comparison with the Ardene sequence
Abstract
Małoskalowa cykliczna sedymentacja we wczesnym żywecie Gór Świętokrzyskich: porównanie z sekwencją Ardenów
In the section of the Lower Givetian limestones exposed in the Jurkowice-Budy quarry (eastern Góry Świętokrzyskie) 6 shallowing-upward small-scale cycles (thickness ranging from 0.5 to 3.3 nr, average 1.5 in) are identified. Each cycle consists of a subtidal to lower-intertidal muddy unit overlain by an upper-intertidal to supratidal unit with extensive dia- genetic overprint, recording progradation processes. Non-erosive discontinuities separate successive conformable cycles. Distinguishing autocyclic from allocyclic processes is ambiguous in the lagoonal-peritidal sequence. Likely, the sedimentation was primarily controlled by local subsidence, pulses of which were counterbalanced by algal production. Climatically induced (in the frame of the Milankovitch cycles), very low-amplitude sea-level oscillations (less than 2 meters?) and short lag times (between 1000 yr and 5000 yr?) during deepening at the base of each cycle might also contributed to the sedimentary record.
In the section of the Lower Givetian limestones exposed in the Jurkowice-Budy quarry (eastern Góry Świętokrzyskie) 6 shallowing-upward small-scale cycles (thickness ranging from 0.5 to 3.3 nr, average 1.5 in) are identified. Each cycle consists of a subtidal to lower-intertidal muddy unit overlain by an upper-intertidal to supratidal unit with extensive dia- genetic overprint, recording progradation processes. Non-erosive discontinuities separate successive conformable cycles. Distinguishing autocyclic from allocyclic processes is ambiguous in the lagoonal-peritidal sequence. Likely, the sedimentation was primarily controlled by local subsidence, pulses of which were counterbalanced by algal production. Climatically induced (in the frame of the Milankovitch cycles), very low-amplitude sea-level oscillations (less than 2 meters?) and short lag times (between 1000 yr and 5000 yr?) during deepening at the base of each cycle might also contributed to the sedimentary record.