New data on the origin of the Fe-Cu-As skarn deposit at Obří důl, West Sudetes, Bohemian Massif
Pašava, J.; Veselovský, F.; Dobeš, P.; Erban, V.; Pour, O.; Žák, Karel; Ackerman, Lukáš; Haluzová, Eva; Creaser, R.; Tásler, R.
2017 - English The Obří důl Fe-Cu-As sulfide deposit is hosted in metamorphosed lenses of marble, calc-silicate rocks and skarns. The deposit is located up to a few hundred meters away from the contact of the large, late-orogenic Variscan Krkonoše-Jizera Plutonic Complex (KJPC). Mineralogical and fluid inclusion studies of the Gustavská ore lens show that the main sulfide stage, dominated by pyrrhotite, chalcopyrite and arsenopyrite, originated from water-rich hydrothermal fluids with salinities up to 8 wt.% NaCl eq. at temperatures ranging from 324 to 358°C.These fluids replaced mainly the carbonate-rich lithologies. The 34S values indicate a magmatic source of sulfur and Re/Os dating of molybdenite are consistent with simultaneous formation of the main sulfide stage ore and the KJPC. Keywords: Obří důl; Bohemian Massif; West Sudetes Available at various institutes of the ASCR New data on the origin of the Fe-Cu-As skarn deposit at Obří důl, West Sudetes, Bohemian Massif

The Obří důl Fe-Cu-As sulfide deposit is hosted in metamorphosed lenses of marble, calc-silicate rocks and skarns. The deposit is located up to a few hundred meters away from the contact of the ...

Pašava, J.; Veselovský, F.; Dobeš, P.; Erban, V.; Pour, O.; Žák, Karel; Ackerman, Lukáš; Haluzová, Eva; Creaser, R.; Tásler, R.
Geologický ústav, 2017

Na Javorce Cave - a new discovery in the Bohemian Karst (Czech Republic): unique example of relationships between hydrothermal and common karstification.
Dragoun, J.; Žák, Karel; Vejlupek, J.; Filippi, Michal; Novotný, J.; Dobeš, J.
2013 - English The Na Javorce Cave is located in the Bohemian Karst, Czech Republic, about 25 km SW of Prague. The cave was formed in vertically dipping layers of Lower Devonian limestone; it is 1,723 m long and 129 m deep, of which 9 m is permanently flooded. The cave is polygenetic, with several clearly separable evolutionary stages. Cavities discovered to date were mostly formed along the tectonic structures of two main systems. One of these systems is represented by vertical faults of generally N-S strike, which are frequently accompanied by vein hydrothermal calcite with crystal cavities. The second fault system is represented by moderately inclined west-dipping faults. Smaller tube-like passages of phreatic morphology connect the larger cavities. The fluid inclusion data obtained for calcite developed along both fault systems in combination with C and O stable isotope studies indicate that the hydrothermal calcite was deposited from moderately NaCl-type basinal fluids (0.5 to 8.7 wt. % NaCl equ Keywords: caves; karstification; karst; Bohemian Karst Available at various institutes of the ASCR Na Javorce Cave - a new discovery in the Bohemian Karst (Czech Republic): unique example of relationships between hydrothermal and common karstification.

The Na Javorce Cave is located in the Bohemian Karst, Czech Republic, about 25 km SW of Prague. The cave was formed in vertically dipping layers of Lower Devonian limestone; it is 1,723 m long and 129 ...

Dragoun, J.; Žák, Karel; Vejlupek, J.; Filippi, Michal; Novotný, J.; Dobeš, J.
Geologický ústav, 2013

New localities of coarsely crystalline cryogenic cave carbonates in Slovakia
Orvošová, M.; Vlček, L.; Žák, Karel
2013 - English Three new localities of coarsely crystalline cryogenic cave carbonates (CCCcoarse) have been recently discovered in the Western Carpathians, Slovakia. CCCcoarse are secondary mineral formations in the cave and belong to speleothems. They occur in the form of loose accumulations of calcite crystals and crystal aggregates freely deposited on the bottom of the cavities. Their genesis is interpreted as related to slow karst-water freezing in pools inside the caves, in relation to the existence of a permafrost zone during Quaternary glacials. The newly discovered CCCcoarse localities in Četníkova svadba Cave, Demänovská j. mieru Cave and Zlomísk Cave are characterized by description and photodocumentation of the present crystal forms, by preliminary C and O isotope data, and by their U-series ages. The ages of the cryogenic crystals are in the range between 47 and 12 ka BP, corresponding to the latter half of the Last Glacial. Any new locality of CCCcoarse formed during the Last Glacial represents an important source of information about paleoclimatic conditions of adjacent areas. The U-series ages of the new localities support the earlier conclusion that the formation of CCCcoarse is related to transitions from cold to warm climate periods within the Last Glacial. Keywords: caves; carbonates; cryogenic carbonates Available at various institutes of the ASCR New localities of coarsely crystalline cryogenic cave carbonates in Slovakia

Three new localities of coarsely crystalline cryogenic cave carbonates (CCCcoarse) have been recently discovered in the Western Carpathians, Slovakia. CCCcoarse are secondary mineral formations in ...

Orvošová, M.; Vlček, L.; Žák, Karel
Geologický ústav, 2013

Miocene-Pliocene age of cave Snežna Jama na Raduhi, Southern Alps, Slovenia
Mihevc, A.; Horáček, I.; Pruner, Petr; Zupan Hajna, N.; Čermák, Stanislav; Wagner, Jan; Bosák, Pavel
2013 - English Snežna jama cave is 1,600 m long horizontal cave at about 1,500 m a.s.l. in Raduha Massif (Kamnik-Savinja Alps) rich in cave deposits (both allogenic sediments and massive flowstones). The cave size, shape and deposits show (1) formation of the cave in different conditions, and (2) its substantial age. A 4.8 m deep pit was excavated in allogenic sediments. Samples were taken both for palaeomagnetic analysis and palaeontological screening. Sediments consist of rhythmically arranged layers deposited in phreatic conditions. Fragments of rodent teeth and a well-preserved molar of genus Baranomys were identified. Fossil remains indicate mammalian zone MN 16 and MN 14. A high-resolution palaeomagnetic analysis revealed total of 3 principal normal polarized and 2 principal reverse polarized magnetozones. If we accept the palaeontologic calibration, the deposition took place within Gauss and Gilbert chrons, from about 2.6 to more than 5 Ma. Long sedimentation period is in concordance with the cave rocky relief that shows phreatic and epiphreatic morphology and predates the main uplift of the area for about 900 m. Keywords: caves; karst; Miocene; Pliocene Available at various institutes of the ASCR Miocene-Pliocene age of cave Snežna Jama na Raduhi, Southern Alps, Slovenia

Snežna jama cave is 1,600 m long horizontal cave at about 1,500 m a.s.l. in Raduha Massif (Kamnik-Savinja Alps) rich in cave deposits (both allogenic sediments and massive flowstones). The cave size, ...

Mihevc, A.; Horáček, I.; Pruner, Petr; Zupan Hajna, N.; Čermák, Stanislav; Wagner, Jan; Bosák, Pavel
Geologický ústav, 2013

Magnetic fabric and mineralogy of cave deposits in Botovskaya Cave (Eastern Siberia, Russian Federation)
Kadlec, Jaroslav; Hercman, H.; Chadima, Martin; Lisá, Lenka; Oberhänsli, H.; Osintsev, A.
2013 - English The Botovskaya Cave is a typical example of a two-dimensional maze with a total length of explored passages exceeding 60 km, which represents the longest limestone cave system in the Russian Federation. The clastic cave sediments filling the cave passages differ in both mineral and mineral magnetic properties and were deposited under different hydrological conditions. The older portion of the clastic cave fills was derived from overlying sandstones, whereas the properties of younger cave sediments show closer affinity to the soils and weathering products originating on the sandstone plateau above the cave. The cave sediments underwent repeated periods of deposition and erosion during the Tertiary and Pleistocene. Keywords: caves; magnetic fabric; mineralogy; cave deposits Available at various institutes of the ASCR Magnetic fabric and mineralogy of cave deposits in Botovskaya Cave (Eastern Siberia, Russian Federation)

The Botovskaya Cave is a typical example of a two-dimensional maze with a total length of explored passages exceeding 60 km, which represents the longest limestone cave system in the Russian ...

Kadlec, Jaroslav; Hercman, H.; Chadima, Martin; Lisá, Lenka; Oberhänsli, H.; Osintsev, A.
Geologický ústav, 2013

Cave formation initiated by dissolution of carbonate cement in qartzose sandstones
Adamovič, Jiří; Mikuláš, Radek; Navrátil, Tomáš; Mertlík, J.
2013 - English Besides cavities of irregular shape, European sandstones also feature symmetrical cavities of spherical, ellipsoidal or teardrop shapes. Most of them are tens of centimetres across but some reach as much as 2–3 m in diameter and may coalesce into large caves tens of metres in length. Their origin has not been clearly explained yet. Based on the field comparison between such cavities in quartzose sandstones and incompletely developed cavities in carbonate-cemented sandstones, it can be demonstrated that the symmetrical cavities form by carbonate dissolution within the limits of former carbonate concretions. The diagnostic features of post-concretionary cavities include their circular or elliptical cross-section, a uniform orientation of their long axes across the region, and the presence of a set of parallel vertical joints or grooves/ribs on their inner walls. In some sandstone areas (e.g., Petite Suisse area in Luxembourg, Kokořín area in the Czech Republic), a wide variety of transitional forms can be found between the cavities and concretions forming positive relief on a vertical cliff face, depending on the position of the carbonate dissolution front in the present landscape. Keywords: caves; sandstones; carbonate cement Available at various institutes of the ASCR Cave formation initiated by dissolution of carbonate cement in qartzose sandstones

Besides cavities of irregular shape, European sandstones also feature symmetrical cavities of spherical, ellipsoidal or teardrop shapes. Most of them are tens of centimetres across but some reach as ...

Adamovič, Jiří; Mikuláš, Radek; Navrátil, Tomáš; Mertlík, J.
Geologický ústav, 2013

Project Namak: some of the most spectacular findings in the Iranian salt karst
Filippi, Michal; Bruthans, J.; Jager, O.; Zare, M.; Asadi, N.
2013 - English Project (“namak” means salt in Persian language) is an informal association of geologists and speleologists who cooperate on exploration and scientific research of the salt karst in southern and southwestern Iran. During the Project(from 1998 until 2013) about 16 salt diapirs were visited and more than 60 caves were discovered, 30 of which were mapped. The most exciting scientific and speleological discoveries were made in the Namakdan, Hormoz and Jahani salt diapirs; however, many other remarkable discoveries have been made on other several Iranian salt diapirs. This contribution summarizes the most interesting findings achieved during the ten expeditions carried out by the NAMAK team. Keywords: speleology; karst; salt karst; Iran salt karst Available at various institutes of the ASCR Project Namak: some of the most spectacular findings in the Iranian salt karst

Project (“namak” means salt in Persian language) is an informal association of geologists and speleologists who cooperate on exploration and scientific research of the salt karst in southern and ...

Filippi, Michal; Bruthans, J.; Jager, O.; Zare, M.; Asadi, N.
Geologický ústav, 2013

Valley incision in the Nízké Tatry Mts. (Slovakia) estimated based on paleomagnetic and radiometric cave sediment datings
Kadlec, Jaroslav; Bella, P.; Čížková, Kristýna; Granger, D. E.; Hercman, H.; Holúbek, P.; Chadima, Martin; Orvošová, M.; Pruner, Petr; Schnabl, Petr; Šlechta, Stanislav
2013 - English Up to eleven horizontal cave levels occur at different altitudes in Jánska, Demänovská and Mošnická karst valleys in the Nízke Tatry Mts. Most of the caves are filled with allochthonous sediments transported from the area formed mostly by granite. The cave levels were filled with fluvial sediments in dependence on the valleys incision caused by Neogene and Pleistocene uplift of the mountain range. The fluvial sediments are intercalated with, or capped, by flowstone layers in the caves. The paleomagnetic polarities measured both in clastic and chemogenic sediments indicate the age of deposition. Based on obtained polarity data we are able to distinguish cave sediments deposited during the Brunhes, Matuyama and Gauss chrons. The paleomagnetic interpretation was partly verified by U-series datings of flowstones preserved in the sedimentary sections. Except for the horizontal cave levels located in the karst valleys, additional large cave systems were found at extremely high altitudes in the Nízke Tatry Mts. 600–700 m above the lowest horizontal cave level. Keywords: caves; caves sediments; dating Available at various institutes of the ASCR Valley incision in the Nízké Tatry Mts. (Slovakia) estimated based on paleomagnetic and radiometric cave sediment datings

Up to eleven horizontal cave levels occur at different altitudes in Jánska, Demänovská and Mošnická karst valleys in the Nízke Tatry Mts. Most of the caves are filled with allochthonous sediments ...

Kadlec, Jaroslav; Bella, P.; Čížková, Kristýna; Granger, D. E.; Hercman, H.; Holúbek, P.; Chadima, Martin; Orvošová, M.; Pruner, Petr; Schnabl, Petr; Šlechta, Stanislav
Geologický ústav, 2013

Field trip 1: Ultramafic volcanic rocks in the Osečná - Upper Ploučnice river region in North Bohemia
Paluska, A.; Veselý, P.; Rapprich, V.; Ulrych, Jaromír
2013 - English Keywords: volcanic rocks; excursion guide; North Bohemia Available at various institutes of the ASCR Field trip 1: Ultramafic volcanic rocks in the Osečná - Upper Ploučnice river region in North Bohemia

Paluska, A.; Veselý, P.; Rapprich, V.; Ulrych, Jaromír
Geologický ústav, 2013

Mineral composition of agricultural soils developed on loess
Žigová, Anna; Šťastný, Martin
2011 - English The study is focused on the comparison of mineral composition of different soil types formed on loess. The soil types were classified according to the World reference base for soil resources. Samples were collected from individual soil horizons. Basic soil properties such as the particle-size distribution, pH values, CaCO3 contents, base saturation, cation exchange capacity, soil organic carbon and nitrogen were analysed using routine pedological methods. Mineral composition was evaluated on the basis of XRD analyses of the fraction < 0.001 mm. Semiquantitative mineral composition was calculated from the areas of basal peaks. The studied soils were found to be dominated by quartz, kaolinite and illite. Semiquantitative analyses of mineral composition of the Greyic Phaeozem, Haplic Chernozem and Haplic Luvisol revealed differences in the association and proportion of individual minerals. Keywords: loess; mineralogy; Haplic Chernozem; Haplic Luvisol; Greyic Phaeozem Available at various institutes of the ASCR Mineral composition of agricultural soils developed on loess

The study is focused on the comparison of mineral composition of different soil types formed on loess. The soil types were classified according to the World reference base for soil resources. Samples ...

Žigová, Anna; Šťastný, Martin
Geologický ústav, 2011