Uwagi o litostratygrafii triasu wąwozu Bukowia (Góry Świętokrzyskie)

Kazimierz Rdzanek



The Bukowie locality is one of less known outcrops of the Mesozoic in the Holly Cross Mts, despite of the fact that this gully excellently displays the Lias (Hettangian and Sinemurian) (2) and almost the whole Triassic. The tectonics is also interesting are here is exposed a section through a brachyantycline with fairly steep limbs and vertical (up to the height of 30 m) Lias layers, about 100 m thick. The paper deals with the development of the Triassic.
Alt Bukowie, the Bundsandstein is terrigenous. This feature makes it possible to place upper boundary of the Bundsandstein between marls (still containing clay as terrigenous component) and limestones, making the onset of carbonate sedimentation of the Muschelkalk.
The lithostratigraphic studies of the Bukowie section appeared insufficient of subdividing the Bundsandstein, and objective factors (i.e. guide fossils) are needed for that purpose. This will be the subject of a successive, microfloristic study of the present author.
The Muschelkalk section is strongly reduced here but, nevertheless, it comprises Lower, Middle and Upper Muschelkalk. The Muschelkalk represents a lagoon formation, characterized by an impoverished organic assemblage. The base and trop oaf that formation are defined by reduction and another increase in frequency of fauna in deposit, respectively.
The Keuper ifs incomplete as the Upper Keuper is missing here in result of pre-Rhaetian erosion (20). The Lower Keuper occurs in sedimentary continuity with the Muschelkalk. It begins with claystones dated by the disappearance of marine phytoplankton Tasmanites anid Leiosphaeridia, guide fossils for the Muschelkalk only (11) .
The Rhaetian, tentatively differentiated here, is represented by yellow oncoid limestones ("pseudoooids"), calcareous and calcareous-quartzitic conglomerates and cherry-red claystones. Such rocks are regarded as typical of the Rhaetian of the northern margin of the Holy Cross Mts (15, 10).

Pełny tekst: