Abstract Fire agates from Deer Creek are highly appreciated gemstones due to the presence of optical phenomena and rainbow colours that cause fiery effects to be observed on their characteristic brown base. The specific morphology of poorly ordered chalcedony (crystallinity index = 0.1–1.5) with an admixture of mogánite (av. 6.6%), micro-quartz and opal-C forming a colloform texture seems to be responsible for the presence of fire effect in these agates. The multi-layered silica spheroidal forms (‘bubble’-like structure), already noted in hand specimens, could be the centres of reflection and interference of white light. Numerous, microscopic inclusions of Fe and Ti compounds randomly scattered within some silica zones, together with microstructural features of agate, could determine the colour and size of the domains with the optical effect. Deer Creek fire agates form veins within their host volcanic rocks. The silica mineralisation filling the network of fissures in the host rocks was supplied cyclically with aqueous fluids of varying composition, enriched periodically in CO 2 , Fe, Ti, Mn, Zn and Ca. As a result, the red-brown colour of fire agates was created by scattered pigments of tiny iron oxides (magnetite, maghemite) and titanium oxides (rutile, anatase) within the silica matrix. The precipitation of strongly disordered silica with a characteristic colloform texture is diagnostic for boiling processes in this area.
The purpose of this contribution is to present the geotourist path in the Chochołowska Valley for the disabled with limited mobility, as well as for the elderly. The Chochołowska Valley is the most westward valley in the Polish Tatra Mountains (Western Tatras). It is the longest and largest valley in the Polish Tatra Mountains, with an area of 35 km2 and 10 km in length. The highest peak located in the Chochołowska Valley is the Starorobociański Wierch at 2176 m a.s.l. The altitude at the end of the valley around Siwa Polana, is about 900 m a.s.l. (from 910 m a.s.l. to 920 m a.s.l.). At the Polana Huciska, where the geotoursit path ends, the altitude is about 1000 m a.s.l. The length of the path is 3.5 km, and the altitude difference over this distance is 100 meters. The Chochołowska Valley is developed in sedimentary rocks (limestones, marls, dolomites), belonging to two nappes: Choč Nappe (e.g. Siwiańskie Turnie outcrop) and Križna Nappe (e.g. Niżna Brama Chochołowska Rock Gate). The valley administratively belongs to the Witów village. A green tourist trail was marked through the valley. It start from the Siwa Polana to the mountain hut named after John Paul II on Polana Chochołowska. An asphalt road is from Siwa Polana to the Polana Huciska. The Chochołowska Valley is one of the most beautiful Tatra valleys with numerous rock outcrops and is considered to have a high geotouristic potential. The proposed geotourist path includes selected outcrops, which can be easily accessed by people with limited mobility, including people in wheelchairs. This path runs along a wide asphalt road, and any additional equipment (e.g. a freewheel for wheelchairs) is not required. A large car parking lot is available at the beginning of the proposed path (Siwa Polana), as well as sanitary and catering facilities.
A new finding of lustrous coal particles from the youngest flysch sediments of the Silesian Nappe, Polish Eastern Carpathians, outcropped in the Bieszczady Mountains is here presented. The coal material occurs in a 1-m thick submarine slump layer in the Kiczera Dydiowska Sandstones, which belong to the youngest part of the Krosno Beds. Coal particles are numerous (up to 16%) in a massive sandstone of the slump layer. The siliciclastic particles from these sediments are classified as material from weathered rocks of continental block or they have been recycled from post-orogenic sediments. Lustrous coal represents coaly plant fragments, which are mostly homogeneous, belonging to macerals of vitrinite group. Some coal pebbles display tree structure, typical of gelified xylites, due to impregnation of cell walls by resinite, which occurrence in this material indicates terrestrial plants producing waxes and resins. Some of gelified plant debris shows evidence of pyritization, what in the absence of inertinite macerals in coal may indicate dysoxic conditions during first decomposition processes of organic matter under water environment. Coaly-bearing slump moved down most probably from SW during Oligocene–Miocene transition time. This shows that an intrabasinal massif, as the uplifted fragment of ?Precambrian craton, which supplied large amount of siliciclastic material to the Silesian–Subsilesian basin during the lower–middle Oligocene, still existed at the end of the Oligocene.
Exotic schist cobbles were collected from two localities: Roztoki Dolne and Ustrzyki Gorne (Krosno Beds, Silesian Nappe, Bieszczady Mts., SE Poland), where they occur in streams as a detrital material. These cobbles reach up to 25 cm in diameter, but a few boulders (up to 1 m) were also found. They were grey and green in colour and had mica and quartz layers (most often thicker than 0.5 cm, although some quartz layers can reach 1 cm). Some exotic cobbles found were tectonically deformed. These investigated schist cobbles consisted of quartz, white mica (phengite) and chlorite. Additionally other minerals which also occurred in cobbles were: garnet (almandine), tourmaline (dravite), and accessory: apatite, zircon, rutile and ilmenite. Biotite (often altered) and feldspar (albite, oligoclase) are rare. Numerous calcite veins were observed. Garnet porphyroblasts had different shapes (spherical, elliptic or tectonically elongated) and sometimes showed zonation. Tourmalines had characteristic blue and brown zones, due to variable contents of Fe. The protolith of the schists analyzed had the character of pelitic-mudstone rocks. The precursor rocks were metamorphosed during both progressive (almandine-amphibolite facies) and retrogressive metamorphism. The north-west extension of the Marmarosh or Rakhiv massifs between Dukla and Silesian subbasins was the most probable source of these exotic cobbles.
The Magura Nappe in the Polish sector of the Outer Carpathians consists of four tectonic subunits characterized by differing development of facies. From the south to the north, they include the Siary, Rača, Bystrica and Krynica subunits. The sedimentary succession in the Rača Subunit in the vicinity of the village of Osielec is composed of Campanian–Palaeogene flysch deposited in the Magura Basin. In this succession, the Middle Eocene Pasierbiec Sandstone Fm consists of thick-bedded sandstones and conglomerates with occasional intercalations of thin-bedded shale-sandstone flysch. Within the Pasierbiec Sandstone Fm at Osielec there is an olistostrome, rich in pebbles and cobbles of exotic rocks. In addition, large blocks of Neoproterozoic metabasites and boulders of Palaeogene organogenic limestones were found. The discovery of metabasites raised the possibility that the rocks in question could be evidence of supposed oceanic crust in the basement of the Magura sedimentary basin, because of the suggestion that they represent the Alpine orogenic cycle. This concept was abandoned when investigations of the absolute age of the metabasites gave a date of ca. 600 Ma. In the Osielec area, there are two tectonic thrust sheets in the Rača Subunit, namely the Osielczyk Thrust Sheet in the north and the Bystra Thrust Sheet in the south; they are folded and cut by a transverse system of strike-slip and oblique faults. The Osielczyk Thrust Sheet was overthrust northwards on to the Siary Subunit.
There are numerous traces of mining activity in the Miedzianka Mountain (Świętokrzyskie Mountains, Poland), because copper and silver ores have been mined in this region since at least the 13th century. The history of scientific research on the Miedzianka Mountain ore deposit spans almost 200 years. Almost 40 minerals have been found: ore minerals of Cu and Fe, and also secondary minerals, including carbonates, sulphates and even very rare arsenates, phosphates and vanadates. Three new minerals have been found, staszicite, lubeckite and miedziankite, but their chemical composition has not been precisely determined and therefore their names have not been approved by the International Mineralogical Association (IMA). The Miedzianka Mountain deposit is an important area on the map of educational activities. It is included in the “Świętokrzyskie Archaeological and Geological Trail” as a site of historical (mining and metallurgy) and natural (geological sciences) heritage. Despite the large potential, none of the underground workings (adits and shafts) are currently available to the public. Our research and exploration of the Teresa adit, which is one of the historical underground complexes of the Miedzianka Mountain, show that this adit displays a wide spectrum of topics in the field of mineralogy, geology and mining history. The Teresa adit, which is a 523 m system of underground corridors, contains 270 m of natural karst caves altered by mining works and is constituted of Upper Devonian limestones, locally cut by cherry shales. In several sites of the adit unique features can be observed, such as: (1) old mining works—galleries carved in the rock back in the 19th century; (2) interesting vein mineralization with secondary-colored copper carbonates and multi-colored calcite veins; (3) mineralization with azurite domination; and (4) karst phenomena (coatings, flowstone, dripstones and stalactites) in a cave part of the adit. The sites with unique features suggest that the Teresa adit is highly suitable to be presented to tourists. That is why we propose seven sites on the underground route that could be the basis for further projects to create a “geotouristic trail” in the Teresa adit. The proposal to make the Teresa adit available to tourists is in line with the tendency to protect the post-industrial landscape associated with former mining activities.
Abstract Studies dealing with the response of subaqueous volcanic and hydrothermal activities to carbonate sedimentation in hemipelagic environments affected by tectonic processes are comparatively rare. Here, a microfacies record with combined chemical data from the neptunian dykes found at an intrabasinal ridge (Tatric Ridge; Carpathian domain of the Western Tethys), close to a source of alkaline volcanism with possible hydrothermal vents (Zliechov Basin), is presented. The characteristic features of the neptunian dykes, up to 20 cm thick, in the middle Albian echinoderm-foraminiferal limestones (Tatra Mountains, Inner Carpathians) are their red fillings. Microprobe and x-ray diffraction analyses show that this reddish material, partly mixed with sparitic clasts coming from the host limestone, consists mainly of hematite crystals which are associated with low crystalline silica and quartz. The microfacies data suggest that the reddish infillings of the dykes is partly related to dissolution processes inside the fissures that could have taken place during the transport of FeCl 3 fluids together with silica gel. The fluids could have been derived from hydrothermal vents occurring along the extensional faults in the neighbouring Zliechov Basin. Rare Earth element (REE) signatures of the reddish infill (i.e. low values of total REE content, chondrite- and Post-Archean Australian Shale-normalized REE + Y patterns with negative Ce anomaly) and a high Y/Ho ratio suggest authigenic removal of REEs from the water column. This suggests that the fissures were open to the sea bottom and were in contact with sea water during their filling.
