Abstract Optical microscopy, scanning electron microscopy with energy dispersive spectrometry, X-ray diffraction, infrared (IR) spectroscopy, Rock-Eval pyrolysis and gas chromatography combined with mass spectroscopy were used to examine deterioration of the black limestone from Dębnik near Cracow. Owing to its unique colour and good polishing properties the rock is called the ‘Dębnik marble’. The samples were taken from various monuments and natural outcrops exposed to weathering. The material is a compact limestone whose black colour is caused by an admixture of bitumens or pyrite. Its horizontal layers are separated by discontinuities filled with clay minerals. Surface exfoliation is one of the damage signs and results in the formation of irregular or lensoidal fractures. The discontinuities provide an easy access for acid rain that in reaction with calcite produces gypsum. Crystallization of gypsum leads to alveolar weathering, cracking and chipping of the otherwise compact material. The presence of alveoles or surface exfoliation depends on the orientation of stone blocks. When they are cut along the discontinuities, destruction results in exfoliating and cracking. Perpendicular cutting gives rise to the formation of alveoles. The changes affect the original black colour of the stone surface that alters to grey or even white.

Upper Triassic (Norian) freshwater carbonates, up to 30 m in thick, occur in the northern part of Upper Silesian basin. These sediments, called the Woźniki Limestone, form a SE-NW–striking elongate (90 km) and narrow (<10 km) belt. The Woźniki Limestone overlies (mostly discordantly) Carnian gypsiferous red beds and underlies the uppermost Triassic–Lower Jurassic continental clastic deposits. Laterally, the carbonates are replaced by a typically red bed clastic assemblage formed under arid and semiarid climatic conditions. Several limestone types have been recognized within the freshwater facies, including travertines, and fluvial, palustrine and pedogenic carbonates. Palustrine limestones form a major component. Common tepee structures, karst breccia, silicified horizons, and weathering breccia indicate that the palustrine carbonates have undergone subaerial exposition and pedogenic alteration. Palustrine carbonate sedimentation has been interrupted and replaced by fluvial sedimentation. The fluvial sediments mark the pluvial climate episodes that inhibited carbonate deposition. The studied basin displays a striking scarcity of lacustrine sediments, which may be explained in terms of hydrological and climatic controls. We infer that the carbonates were deposited within shallow swampy depressions, fed by springs of deep-circulating groundwater, partly of hydrothermal nature, under dry and semidry paleoclimatic conditions in a fault-bounded basin. The travertines precipitated directly near the springs, whereas the remnant solutions formed a broad swamp area where palustrine carbonates formed. It seems very likely that the carbonate-bearing solutions were causally related to the hydrothermal karst that occurs within the Triassic and Paleozoic basement limestones. La parte norte de la cuenca alta de Silesia incluye una unidad de carbonatos de agua dulce, de 30 metros de potencia y edad Triásico Superior (Noriense). Estos sedimentos, denominados Caliza Woźniki forman un cinturón estrecho y alargado (<10 km) en dirección SE-NW. La Caliza Woźniki se apoya, casi siempre discordante, sobre las capas yesíferas rojas del carniense y sobre ella se sitúan los depósitos continentales del Triásico más alto y Jurásico inferior. Lateralmente estos carbonatos pasan a las capas rojas detríticas formadas bajo condiciones climáticas áridas y semiáridas. Las calizas están formadas por distintos tipos de facies que incluyen: facies fluviales, palustres, pedogénicas y de surgencias. Las calizas palustres son las más abundantes. Rasgos como “tepees,” brechas cársticas, horizontes silicificados y brechas de alteración indican que los carbonatos palustres sufrieron exposición subaérea y pedogénesis. La sedimentación palustre carbonática quedó interrumpida por una etapa posterior de sedimentación fluvial, que indica climas más húmedos. Los depósitos lacustres ss, que normalmente son anteriores a los palustres, son muy escasos en esta cuenca. Esto puede ser debido a los controles hidrológicos y climáticos. Así, si se tienen en cuenta las condiciones áridas y semiáridas, el hecho de que los bordes de la cuenca son fallas y la abundancia de travertinos, se puede considerar que los carbonatos se depositaron en una depresión somera y pantanosa, abastecida por surgencias de aguas freáticas profundas (en parte hidrotermales). Los travertinos se formaron por precipitación directa en las zonas cercanas a las surgencias, mientras que el resto del agua se acumuló en depresiones pantanosas amplias donde se formaron los carbonatos palustres. Parece muy probable que las soluciones ricas en carbonato tuvieran relación con el carst hidrotermal que se desarrolló en las calizas del Triásico y Paleozoico.

Abstract A zone of deformation characterized by en echelon folds extends along the northeast margin of the Upper Silesian Coal basin in southern Poland. The zone is well exposed by mining in numerous collieries where the deformation involving Upper Carboniferous strata can be observed. Folds and associated faults form a structural pattern consistent with an origin in dextral convergent wrenching on both the principal deep-seated fractures and the subsidiary faults affecting crystalline basement beneath this part of the basin. The zone is cross-cut by sublatitudinal fold belts which, according to their geometrical parameters, seem to result from alternate transcurrent shearing along west-east oriented fractures in the basement, sinistral in one case and dextral in the other. Among folds caused by the concentrated operation of a force couple whose vectors lie in the horizontal plane, there are examples of bending folds (forced folds) in each array resulting from vertical components of movement of deep-seated fault blocks. The dimensions of the folds change with depth, and the axial trend and the inclination of axial surfaces differ with distance from the basement fault trace. The length of fold segments strongly depends on axes orientation. Widely distributed evidence of interlayer slip demonstrates a variable spatial distribution of tectonic-transport direction in the sedimentary sequence. The above-mentioned features and other geometrical attributes of the fold arrays enable the dynamics of the forcing structures during Variscan tectogenesis to be determined and illustrate a hierarchical structure of the basement boundary zones. Examples from the Silesian-Cracovian region suggest that bending folds (forced folds) can sometimes originate in conditions provided by a strike-slip regime.

Abstract Zinc and lead ores of the Silesia-Cracow district in southern Poland occur mainly in dolostones of the Middle Triassic Muschelkalk Formation but less important deposits and occurrences are also present in Jurassic, Lower Triassic, and Devonian carbonate rocks. The most important deposits are hosted in the “ore-bearing dolostone” which occurs mainly in the lower Muschelkalk Formation. The ore-bearing dolostone consists of extensive diagenetic replacement of limestone and locally, sparry dolomite cement related to ore deposition. Replacement of the carbonate rocks by sulfide minerals is the principal type of ore occurrence; lesser amounts occur as open-space filling of fractures and as cement for breccias of tectonic, dissolution collapse, and sedimentary origins. Sulfide mineralization in ore-stage hydrothermal dissolution collapse breccias is locally well developed in some ore deposits. However, most of the ore-bearing dissolution collapse breccias are interpreted to be the result of selective sulfide replacement of pre-ore collapse breccias. Values of lead isotopes show no variation through the district or the paragenetic sequence and are consistent with the lead being derived from a large crustal reservoir. The lack of measurable variation in the lead isotopic data and conodont CAI studies suggests that the duration of mineralization must have been relatively short. Fluid inclusions in sphalerite are mostly two-phase aqueous liquid plus vapor but organic liquid-bearing fluid inclusions are abundant. Fluid inclusion homogenization temperatures in sphalerite are between 40° and 156°C and salinities range from near 0 to > 23 wt. % NaCl eq. Fluid-inclusion homogenization temperatures increase with depth below the surface and are consistent with a cooling gradient of the ore-fluids of about 6° to 10°C per hundred meters. Temperature-salinity relationships and their variations widi depth are interpreted to indicate the mixing of multiple fluids during ore formation. Analysis of electrolytes in inclusion fluids show that later ore stage sulfides have significantly more bromide, ammonia, and acetate than sulfides in early ore stages. Fluid inclusion gases in sphalerite and galena appear to contain at least two end-member compositions characterized by either CO 2 -CH 4 or CO 2 -H 2 S gas compositions and are consistent with the presence of multiple ore fluids in the ore-forming environment. The deep circulation of fluids inboard from the Carpathian orogenic belt during waning stages of Alpine orogeny may have allowed fluids to acquire heat and extract zinc and lead from a large crustal reservoir to form a metal-bearing fluid. Late Alpine faulting together with the reactivation of pre-existing basement faults along the Cracow-Myszkow zone enhanced the fracture permeability in the carbonate rocks of the district and provided pathways for the ascent of metal-bearing fluids. The mixing of relatively hot, Zn-Pb bearing fluids with fluids from diverse aquifers containing reduced sulfur of different sulfur isotopic compositions can account for the wide range in sulfur isotopes and fluid inclusion observations. Faulting in the ore district, coeval with migration of the ore forming fluids, produced fundamental changes in ore fluid pathways and aquifers. These changes account for the temporal trends in the chemical and isotopic character of the ores through the mineral paragenesis.