Chlorite, ordered mixed-layer chlorite-smectites, laumontite, quartz and albite are the most widespread alteration assemblage in cone-building and near-vent successions of lavas, autoclastic, ...pyroclastic and resedimented volcaniclastic deposits of the Oligocene Smrekovec Volcanic Complex, Slovenia. Randomly interstratified corrensite-chlorite with ~70–80% of corrensite layers (R0 Cr-Ch) is less common in occurrence and associated either with clinoptilolite and heulandite in fine-grained vitric tuffs, or with prehnite, laumontite, actinolite, analcime and albite in extensively altered and/or fractured host-rocks. The assemblage with clinoptilolite and heulandite indicates the temperatures of formation of <~120°C and can be regarded as intermediate in the prograde alteration process of volcanic glass that leads in progressively increasing temperature regime to the formation of chlorite, laumontite, prehnite and albite. The assemblage of R0 Cr-Ch, prehnite, laumontite and actinolite developed in different superimposed temperature regimes and/or stages of hydrothermal activity related to the emplacement and subsequent gradual cooling of the Kramarica Sill. The formation of prehnite and actinolite signifies the highest-temperature conditions attaining up to ~300°C. Laumontite and R0 Cr-Ch extensively developed during the cooling period and as a result of the incursion of alkaline Ca-Mg hydrothermal fluids that possibly evolved from deep ground-waters convecting through Triassic dolomite in the basement of the submarine Smrekovec stratovolcano-hosted hydrothermal system.
•R0 corrensite-chlorite, R1 chlorite-smectite, chlorite, prehnite and zeolites formed by hydrothermal alteration.•Several superimposed mineral assemblages developed during the emplacement (≤300°C) and cooling of the Kramarica Sill.•Laumontite and R0 corrensite-chlorite formed in coarse-grained and/or fractured rocks during the cooling of the sill.•The reacting hydrothermal fluids were possibly rich in the Mg2+ and Ca2+ ions and originated from the dolomite basement.
Hydrothermal zeolites (laumontite, yugawaralite, analcime, heulandite, clinoptilolite), prehnite and pumpellyite have been recognised in a succession of volcanic, autoclastic, pyroclastic, ...resedimented volcaniclastic and mixed siliciclastic–volcaniclastic deposits. In cone-building lithofacies association attaining 310m, the alteration minerals commonly change within a single normally graded depositional unit or alternate in the section on a dm- to m-scale, according to the host-rock lithofacies. Fine-grained deposits rich in juvenile glassy pyroclasts are altered to heulandite and clinoptilolite or analcime, and laumontite widely occurs in coarse-grained host-rocks (lapilli tuff, hyaloclastite breccia, volcaniclastic breccia, hyaloclastites) and fracture systems. In near-vent lithofacies association attaining 420m, prehnite–laumontite, laumontite–analcime, and laumontite–heulandite–clinoptilolite zones developed as a result of superimposed thermal regime generated by the emplacement of an over 200m thick sill.
The recognised dependence of alteration on porosity, permeability and fracturing of the host-rock is closely related to hydrological conditions in the stratovolcano-hosted hydrothermal system with convective–advective flow regime. After separation of steam and gases from convecting hydrothermal fluids, denser liquids outflowed intermittently, preferentially through steeply inclined (20–30°) high-permeability layers in the stratovolcano edifice. In low-permeability layers the flow was slow and thermal conditions were mainly attained by conduction. Zeolites developed only in coarse- and fine-grained vitroclastic tuffs, presumably by the dissolution of volcanic glass. The interstratified siliciclastic siltstones, tuffites and resedimented deposits with low content of glassy particles are devoid of zeolites and indicate compositional constraint on zeolitisation.
Lava flows, cooling in a submarine environment and undergoing disintegration and mingling with the enclosing water-saturated sediment were individual, ephemeral and spatially localised high-temperature hydrothermal systems favourable for the formation of pumpellyite, prehnite and laumontite.
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•Oligocene submarine stratovolcano hosted hydrothermal system•Host-rock lithofacies and convective–advective flow regime controlled alteration.•Laumontite and prehnite are common in coarse-grained deposits.•Heulandite and clinoptilolite dominate in fine-grained vitoclastic tuffs.•Peperites were altered by the inherited heat of disintegrating lava flow.
The Upper Oligocene Smrekovec Volcanic Complex (SVC) represents the remains of a submarine stratovolcano which underwent Early Miocene tectonic dissection and large-scale displacement along the ...Periadriatic Line. According to the lithofacies architecture, abundance and spatial distribution, central, medial and distal zones of the former volcano edifice have been recognized. The zones extend at a distance of 0–2km, 2–5km and 5–20km south of the Periadriatic Line, respectively.
Lavas, shallow intrusive bodies, autobreccia, peperite and hyaloclastite deposits occur mainly in the central zone, which is extensively altered under hydrothermal conditions, characterised by the development of zeolites (mainly laumontite), prehnite, chlorite, albite and epidote. Explosive volcanic activity intensified with the evolution of magma from basaltic andesitic to dacitic. Gas- and water-supported eruption-fed density flows are assumed. Their deposits show lithofacies organisation in pyroclastic depositional units (PDUs) similar to either volcaniclastic turbidites (Type 1) or thin subaqueous ignimbrites (Type 2).
Volcaniclastic debris flow deposits are developed as volcaniclastic breccia and sandy debris flow deposits; the former occurs in the central and medial zones, and the latter occurs in the medial zone only.
The most widespread lithofacies in the SVC are volcaniclastic turbidite deposits. Three types of sedimentary unit (TSU) have been distinguished. Type 1 is 2–5m thick and dominated by the massive division. It mainly occurs in the central zone. Type 2 is 0.7–3.5m thick and occurs in the central and medial zones. It comprises the massive division, bedded fining- and thinning-upward division, and a horizontally, wavy and cross-laminated division, topped by massive fine-grained tuff. Type 3 is 0.1–1.5m thick and mainly occurs in the distal zone. The massive division is absent, and thinly-bedded and laminated divisions are topped by massive fine-grained tuff. Volcaniclastic turbidites were settled from low-density turbidity currents and related suspension clouds.
Mixed volcaniclastic–siliciclastic deposits are subordinate in occurrence and restricted to the distal zone. They are commonly reworked by bottom currents.
► Volcaniclastic deposits are widespread in the submarine Smrekovec Volcanic Complex. ► Autobreccias and peperites occur along the margins of lavas and shallow intrusives. ► Pyroclastic deposits originate from eruption-fed density flows. ► Volcaniclastic turbidites are organised in fining-upward sedimentary units. ► Lithofacies assemblages denote volcano's proximal, medial and distal zones.
This paper provides phytosociological tables that describe scrub and forest communities with Alnus viridis in the Slovenian Alps. We described three new associations: Rhododendro hirsuti-Alnetum ...viridis (a green alder community on calcareous bedrock in the Eastern and Southeastern Alps), Huperzio selagi-Alnetum viridis (a green alder community in the silicate rocks under Mt. Komen in the eastern Savinja Alps) and Alno viridis- Sorbetum aucupariae (a successional stage of mountain ash and green alder on potential beech sites in the foothills of the southern Julian Alps; similar stages are known also elsewhere in the Alps), and presented additional three associations (Polysticho lonchitis-Fagetum, Rhodothamno-Laricetum and Rhododendro hirsuti-Pinetum mugo) whose stands comprise green alder.
V članku s fitocenološkimi tabelami opisujemo grmiščne in gozdne združbe, v katerih v slovenskih Alpah uspeva vrsta Alnus viridis. Opisali smo tri nove asociacije: Rhododendro hirsuti-Alnetum viridis (združba zelene jelše na karbonatni podlagi v vzhodnih in jugovzhodnih Alpah), Huperzio selagi-Alnetum viridis (združba zelene jelše v silikatnem skalovju pod goro Komen v vzhodnih Savinjskih Alpah) ter Alno viridis-Sorbetum aucupariae (sukcesijski stadij jerebike in zelene jelše na potencialno bukovih rastiščih v prigorju južnih Julijskih Alp, podobne stadije poznajo tudi drugod v Alpah) ter predstavili še tri druge asociacije (Polysticho lonchitis-Fagetum, Rhodothamno-Laricetum in Rhododendro hirsuti-Pinetum mugo), v čigar sestojih uspeva zelena jelša.
Production from geothermal reservoirs in volcanic-igneous hydrothermal systems may be disturbed owing to the formation of authigenic minerals that reduce primary porosity and infill fissure systems. ...Crystallization may be induced by natural processes or human activity related to the reservoir exploitation. In volcanic and volcaniclastic rocks, zeolites and related authigenic silicate minerals commonly develop. Two selected study sites—Pauzhetka geothermal field in Russia and Smrekovec volcanic complex in Slovenia are characterized by extensive development of progressive stage medium- and low-temperature propylitization and zeolitization with similar mineral assemblages that reduced original reservoir rock porosity and permeability. Retrograde and overprinting reactions of argillitization commonly enhance porosity and permeability of rocks, but some other reactions, like from prehnite to laumontite, from laumontite to heulandite, and from laumontite to analcime, encountered in the Smrekovec volcanic complex reduced it appreciably. Retrograde reactions recognized in the study sites were not induced by the temperature drop only, but were accompanied by the change in chemical composition of reacting fluids. Chemical composition of interstitial waters produced from exploitation wells in the Pauzhetka geothermal field indicate that propylitic and zeolite facies alteration is related to Na–Cl, slightly alkaline waters, while argillitization involved acidic thermal waters with more complex ion composition.
In Tertiary basins of NE Slovenia, Upper Oligocene volcanic activity occurred in a submarine environment that experienced contemporaneous clastic sedimentation. Pyroclastic deposits are essentially ...related to gas- and watersupported eruption-fed density currents. At Trobni Dol, the Lako Basin, an over 100 m thick deposit formed by a sigle sustained volcanic explosion that fed gas-supported pyroclastic flow. Diagnostic features are large matrixshard content, normal grading of pumice lapilli, collapsed pumice lapilli and the presence of charcoal. In the Smrekovec Volcanic Complex, several but only up to 5 m thick deposits related to eruption-fed gassupported pyroclastic flows occur. Deposits settled from water-supported eruption-fed density currents form fining- and thinning-upward sedimentary units which resemble the units of volcaniclastic turbidites. Pyroclastic deposits related to gas- and water-supported density currents occur in an up to 1000 m thick succession composed of coherent volcanics, autoclastic, pyroclastic, reworked volcaniclastic and mixed volcaniclastic-siliciclastic deposits that indicate a complex explosive and depositional history of the Smrekovec Volcanic Complex.
Styrian motorway crosses the Pletovarje ridge through the tunnel having the same name. It intersects the mosteastern extension of the Southern Karavanke tectonic unit. Considering geological ...conditions, the tunnel couldbe divided into three sections: the inner Donat / Dona~ka fault zone composed of tectonic lenses of differentlithostratigraphic units (of paleozoic, triassic and tertiary age), massive dolomite (lower triassic) and Smrekovecseries of oligocene age. Main faults have east – west direction and are subvertical.
Provider: - Institution: - Data provided by Europeana Collections- Ko je bila naša družina še zelo mlada, smo radi pohajali po gorskih poteh. Na tale poletni dan leta 1998 smo se odločili, da jo ...mahnemo na Smrekovec, ki ga iz naših krajev vsakodnevno spoštljivo gledamo navzgor. Do Slemena smo se peljali z avtomobilom, nato pa smo nadaljevali, kot se spodobi, peš. Otroka sta jo veselo mahala pred nama. Pri koči smo se osvežili in okrepčali, nato pa smo se povzpeli do golega vrha. Razgled je ravno zaradi tega veličasten, saj ga ne zastirajo gozdna drevesa. Odpočili smo si, nahranili dušo, nato pa polni lepih vtisom odšli proti domu. Ta ugasel ognjenik nam je od takrat še ljubši, saj je del spominov naše družine.- All metadata published by Europeana are available free of restriction under the Creative Commons CC0 1.0 Universal Public Domain Dedication. However, Europeana requests that you actively acknowledge and give attribution to all metadata sources including Europeana
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