Deprecated: Function get_magic_quotes_gpc() is deprecated in /home/isthin5/public_html/addon-domains/speleogenesis.info/template/toolbar_right.php on line 7
Search in KarstBase
![]() |
![]() |
The development of caves influenced by the deep circulation of water has received increasing interest for the last thirty years. Presently, hypogene caves have been recognized all around the world. Conversely, the ancient examples filled with sediments and representing palaeokarst forms are not so common.
The karst forms and their sediment fillings were encountered in the Dębnik Anticline (Kraków region, Southern Poland) composed of Middle Devonian to Mississippian carbonates. The development of karst slightly postdates the Permian (ca. 300 Ma) volcanic activity in the Kraków region. In this region major transcontinental strike and slip Hamburg-Kraków-Dobruja fault zone induced a series of minor, en echelon, extensional faults, which served as magma passages and guided karst conduits.
The karst forms in the Dębnik Anticline reach several to tens of meters in size. They are filled with: i) massive, subaqueous, coarse crystalline calcite spar; ii) crystalloclastic, bedded limestones; iii) jasper lenses; iv) kaolinitised tuffs. The sediments are characterized by red colouration caused by iron compounds.
Coarse crystalline calcite spar composes beds up to several dozen centimeters in thickness. They are laminated and comprise frutexites type structures. The calcites are interbedded with pinkish-red crystalloclastic limestones, which are built of detritic calcite crystals from silt size to a few millimeters across. Some of the crystals are of skeletal type. Crystalloclastic limestones are normally graded. Both calcite spar and crystalloclastic limestones underwent synsedimentary deformations, which resulted in brecciation and plastic deformations.
The above deposits fill karst forms up to a few metres in lateral extent. However, analogously filled enormously huge (up to around 100 m across) forms were recognized in the early 80s of the last century. Presently, they are completely exploited.
The karst forms were fragments of extensive circulation system. It was fed by waters of elevated temperature, rich in endogenic CO2, which is proved by fluid inclusion analysis and stable isotope investigation. The origin of this system was associated with volcanic activity. The roots of the system are represented by fissures filled with coarse crystalline, red and white calcites of onyx type, which are common in the Dębnik Anticline. Water issuing from this system on the surface caused precipitation of red travertines. These travertines are preserved only as clasts in the Lower Permian conglomerates deposited in the local tectonic depressions.
The study was financed by Ministry of Science and Higher Education project N307 022 31/1746.
A spectacular pinnacle karst in the southwestern coastal part of Western Australia consists of dense fields of thousands of pinnacles up to 5 m high, 2 m wide and 0.5–5 m apart, particularly well exposed in Nambung National Park. The pinnacles have formed in the Pleistocene Tamala Limestone, which comprises cyclic sequences of aeolian calcarenite, calcrete/microbialite and palaeosol. The morphology of the pinnacles varies according to the lithology in which they have formed: typically conical in aeolianite and cylindrical in microbialite. Detailed mapping and mineralogical, chemical and isotopic analyses were used to constrain the origin of the pinnacles, which are residual features resulting mainly from solutional widening and coalescence of solution pipeswithin the Tamala Limestone. The pinnacles are generally joined at the base, and the stratigraphy exposed in their sides is often continuous between adjacent pinnacles. Some pinnacles are cemented infills of solution pipes, but solution still contributed to their origin by removing the surrounding material. Although a number of pinnacles contain calcified plant roots, trees were not a major factor in their formation. Pinnacle karst in older, better-cemented limestones elsewhere in theworld is similar inmorphology and origin to the Nambung pinnacles, but is mainly influenced by joints and fractures (not evident at Nambung). The extensive dissolution associatedwith pinnacle formation at Nambung resulted in a large amount of insoluble quartz residue, which was redeposited to often bury the pinnacles. This period of karstification occurred at aroundMIS 5e, and therewas an earlier, less intense period of pinnacle development duringMIS 10–11. Both periods of pinnacle formation probably occurred during the higher rainfall periods that characterise the transition from interglacial to glacial episodes in southern Australia; the extensive karstification around MIS 5e indicates that the climate was particularly humid in southwestern Australia at this time.
![]() |
![]() |