Influence of fissuring and karstification of the carbonate aquifer unsaturated zone on its vulnerability to contamination (Cracow Upper Jurassic Region, Poland)

The carbonate fissure–karstic aquifer of Upper Jurassic age is the main aquifer in the Cracow Upper Jurassic Region (CUJR). The aquifer is recharged directly or indirectly by Quaternary or Quaternary–Cretaceous overburden of varying permeability, which predominates diffused recharge. Concentrated recharge occurs locally and has a diverse nature. Field studies carried out in 20 quarries show moderate permeability of the unsaturated zone of carbonate massif. Karst funnels are filled with rubble and clay material and dominate filled fissures with an opening b < 10 mm. The average surface fissure porosity of massive with chalky limestones and bedded limestones reach 0.12 and 0.45 %, respectively, while fissure permeability coefficient is, respectively, k S 6.60 × 10−5 and 1.27 × 10−3 m/s. The average karstification in quarries was determined as n k = 2.5 %. Tracer studies, carried out in an unconfined carbonate Zakrzówek horst in Cracow (Kraków), document vertical migration of infiltrating water through the systems with different hydraulic resistance, with a flow rate from 8.1 × 10−6 to 4.9 × 10−5 m/s and the lateral migration velocity between communicated caves from 6.94 × 10−6 to 1.06 × 10−4 m/s. The significant presence of poorly permeable overburden and moderate fissuring and karstification of rock in the unsaturated zone of CUJR are reflected in the assessment of the Upper Jurassic aquifer vulnerability to contamination, performed by a modified DRASTIC method. In the area of unconfined karst, occupying 55 % of the area, vulnerability to contamination is high, while as much as 45 % of the area is characterized by medium and low vulnerability

Foraminiferal assemblages as palaeoenvironmental bioindicators in Late Jurassic epicontinental platforms: relation with trophic conditions

Foraminiferal assemblages from the neritic environment reveal the palaeoecological impact of nutrient types in relation to shore distance and sedimentary setting. Comparatively proximal siliciclastic settings from the Boreal Domain (Brora section, Eastern Scotland) were dominated by inner−shelf primary production in the water column or in sea bottom, while in relatively seawards mixed carbonate−siliciclastic settings from the Western Tethys (Prebetic, Southern Spain), nutrients mainly derived from the inner−shelf source. In both settings, benthic foraminiferal assemblages increased in diversity and proportion of epifauna from eutrophic to oligotrophic conditions. The proximal setting example (Brora Brick Clay Mb.) corresponds to Callovian offshore shelf deposits with a high primary productivity, bottom accumulation of organic matter, and a reduced sedimentation rate for siliciclastics. Eutrophic conditions favoured some infaunal foraminifera. Lately, inner shelf to shoreface transition areas (Fascally Siltstone Mb.), show higher sedimentation rates and turbidity, reducing euphotic−zone range depths and primary production, and then deposits with a lower organic matter content (high−mesotrophic conditions). This determined less agglutinated infaunal foraminifera content and increasing calcitic and aragonitic epifauna, and calcitic opportunists (i.e., Lenticulina). The comparatively distal setting of the Oxfordian example (Prebetic) corresponds to: (i) outer−shelf areas with lower nutrient input (relative oligotrophy) and organic matter accumulation on comparatively firmer substrates (lumpy lithofacies group) showing dominance of calcitic epifaunal foraminifera, and (ii) mid−shelf areas with a higher sedimentation rate and nutrient influx (low−mesotrophic conditions) favouring potentially deep infaunal foraminifers in comparatively unconsolidated and nutrient−rich substrates controlled by instable redox boundary (marl−limestone rhythmite lithofacies).This research was carried out with the financial support of projects CGL2005−06636−C0201 and CGL2005−01316/BTE, and University of Oslo, Norway−Statoil cooperation. M.R. holds a Juan de la Cierva grant from the Ministry of Science and Technology of Spain

Wiek i znaczenie żwirowców w jaskiniach okolic Krakowa (Jura Polska)

Fine-grained conglomerates have been found in five caves in the southern part of Polish Jura: Wierzchowska Górna, Nad Zródlem V, Bez Nazwy, Jama Ani, Schronisko ze Zwirem. The conglomerates are matrix-supported and are composed of dark grains, quartz grains, clasts of Upper Jurassic limestones, ferruginous clay matrix and carbonate cement. The dark grains, characteristic of the conglomerates, formed in Oxisols in tropical or subtropical climate. The soils formed in Palaeogene, probably in Eocene time. They were eroded in Oligocene or Miocene time and their physically resistant components were redeposited into caves, forming the conglomerates. Pliocene erosion removed the conglomerates nearly completely, so that only small fragments of them are preserved until now.W pięciu jaskiniach południowej części Jury Polskiej (Jaskinia Wierzchowska Górna, Jaskinia nad Źródłem V, Jaskinia bez Nazwy, Jama Ani, Schronisko ze Żwirem) stwierdzono występowanie żwirowców. Żwirowce o rozproszonym szkielecie ziarnowym składają się z: ciemnych ziarn, ziarn kwarcu, fragmentów wapieni górnej jury i ilasto-żelazistego matriks. Żwirowce spojone są węglanowym cementem. Charakterystyczne dla żwirowców ciemne ziarna są pochodzenia pedogenicznego i powstały w glebach typu Oxisol w warunkach klimatu tropikalnego lub subtropikalnego. Gleby te rozwijały się w paleogenie, zapewne w eocenie. W oligocenie lub miocenie były one rozmywane, a ich mechanicznie odporne komponenty były redeponowane w jaskiniach tworząc żwirowce. Większa część tych żwirowców uległa następnie erozji w pliocenie tak, że do dzisiaj zachowały się jedynie ich niewielkie fragmenty

Morfologia Jaskini Czarnej i jej znaczenie dla geomorfologicznego rozwoju Doliny Kościeliskiej

Czarna Cave represents phreatic cave with multiple loops. No cave level developed at the water table was detected. The cave was later modified by invasion vadose waters and breakdown processes. The phreatic paleoflow directions were analyse from the asymmetry of scallops. The paleoflow was directed from the east to the west, that is in a direction of the Kościeliska Valley. Therefore, this valley represented the main discharge zone of the region during the formation of Czarna Cave

Formation of calcite by chemolithoautotrophic bacteria – a new hypothesis, based on microcrystalline cave pisoids

A new mechanism, stimulating the precipitation of calcite, is postulated. The supersaturation with respect to carbonate minerals is changed, as a result of CO2consumption by chemolithoautotrophic, hydrogen-oxidizing bacteria. This mechanism controls the growth of atypical, microcrystalline cave pisoids in Perlová Cave, in Slovakia. The pisoids grow under calm conditions in rimstone pools, where they are bathed continuously in stagnant water. The water is supersaturated, with respect to calcite and aragonite. The bacteria inhabit the outer parts of the pisoids, covered by biofilms. The biofilm influences the supply of the Ca2+ ion, slows down the precipitation rate, and favors calcite precipitation over that of aragonite. The calcite initially precipitates as bacterial replicas, which further act as seeds for the growing calcite crystals. This process leads to the obliteration of the primary, bacterial fabrics. Since hydrogen-oxidizing bacteria occur in a wide spectrum of natural habitats, the mechanism of calcification, postulated above, also may operate in other environments

Needle-fibre calcite and nanofibres as components of Holocene fissure-filling carbonates in southern Poland

The article deals with the carbonates, filling fissures in limestone bedrock and presently exposed in a south-facing rock wall of Kramnica hill (Pieniny Klippen Belt, southern Poland). The carbonates are composed of (i) needle-fibre calcite crystals, (ii) carbonate nanofibres, (iii) carbonate nanoparticles, and (iv) micrite and sparite calcite crystals. Detrital grains from the carbonate bedrock occur subordinately. The spatial relationships of the components give documentation that the nanofibres were formed simultaneously with or slightly later than the needle-fibre calcite crystals. There exists a continuous chain of forms from nanoparticles to elongated nanofibres. This, in turn, indicates that all the above morphological forms are related genetically. In relatively wide fissures, the carbonates studied formed stepped microterracettes, similar to those of speleothems, mainly of moonmilk type. Conversely, narrow fissures are completely filled with carbonates, which display parallel lamination. The carbonates were formed in the late Holocene. However, “dead carbon effect” precludes the possibility of any precise dating of them. Their δ13C and δ18O values are in ranges from -5.1‰ to -3.8‰ and from -6‰ to -4.7‰, respectively. The carbonates studied bear a strong resemblance to soil and spelean, moonmilk-type carbonates. This indicates that continuity exists between the depositional environments of soil and spelean carbonate

Sedimentation of the coal-bearing succession in the Upper Silesia Coal Basin: research trends and the current state of knowledge

The coal-bearing succession in the Upper Silesia Coal Basin consists of molasse deposits filling a flexural foredeep basin. Analysis of lithofacies in cores from deep boreholes revealed the presence of depositional environments typical of alluvial plains and coastal (in a broad sense) environments. Accumulation compensated regional subsidence, so that general depositional surface remained nearly flat. The higher part of the csuccession was laid in fluvial systems, while the lower part mostly in fluvial systems and subordinately in complex coastal systems. Reconstruction of depositional architecture has shown lateral variation in thickness and extent of individual lithosomes, and also pointed to the role of peat-compaction control in shaping their 3D geometry. Sedimentation was controlled by both autigenic and allogenic factors