Stratigraphic position and facies significance of the limestone bands in the subsurface Carboniferous succession of the Lublin Upland

The Carboniferous paraIic succession (late Visean - Westphalian A ) of the subsurface Lublin Basin in eastern Poland yields carbonate deposits, which dominate in the Visean phase of sedimentation, and become more subordinate towards the younger units (Yoredale-type cyclothems). Numerous, perfectly preserved calcareous algae and microproblematics, as well as fairly frequent conodonts indicate an overlapping of the succeeding uppermost Visean strata, and precise the position of the Visean/Namurian and Namurian B /Namurian C boundaries. The five conodont zones have been distinguished: the Lochriea nodosa, the Lochriea cruciformis, the Gnathodus bollandensis, the ldiognathodus sinuosus-ldiognathodus delicatus, and the ldiognathoides tuberculatus zones. The lower boundary of the cruciformis Zone is postulated to coincide with the Visean/Namurian boundary. The presence of ldiognathoides tuberculatus Zone indicates a close relationship of the Lublin Basin with the upper Bashkirian basins of the East European Platform. A distinction of the five algal zones: the Koninckopora, the Kulikia sphaerica, the Calcifolium punctatum, the Calcifolium okense, and the Masloviporidium-Anthracoporellopsis zones enables to correlate regional complexes as well as distant sections, ranging from northern England to the Ukrainian Lvov-VoIhynian Basin, and farther east to the Moscow and Dneper-Donets Basins, in the interval corresponding to the latest Visean - earliest Namurian. The microfacies spectrum of limestone complexes and bands, dominated by the lagoonal algal and spiculitic, and the more distal foraminiferaI and crinoidal lithotypes, bears evidences of local and temporary shoalings marked by peloid microfacies, featured by structures typical of early cementation and emersion. A comparison of microfacies succession in the Limestone Band C (random arrangement) and Limestone Band F (shalIowing upward), and application of LEEDER & STRUDWICK'S sedimentary models indicate a transformation of sedimentary regime in the earliest Namurian. An autocyclic, deltaic pattern of the late Visean changed into an allocyclic system in the Namurian A , with duration of particular cycles estimated as about 500 k.y. This sedimentary turnover is recognized to coincide with the beginning of the Gondwanan glaciation, and thus it suggests a eustatic cause of the lower Namurian cyclicity in the Lublin Carboniferous Basin. Normal 0 21 false false false PL X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:Standardowy; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin-top:0cm; mso-para-margin-right:0cm; mso-para-margin-bottom:10.0pt; mso-para-margin-left:0cm; line-height:115%; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin;}