High-pressure metamorphism in the Pohorje Mountains of Slovenia (Austroalpine unit, Eastern Alps) affected N-MORB type metabasic and metapelitic lithologies. Thermodynamic calculations and ...equilibrium phase diagrams of kyanite-phengite-bearing eclogites reveal PT conditions of >2.1 GPa at T<750 degrees C, but within the stability field of quartz. Metapelitic eclogite country rocks contain the assemblage garnet + phengite + kyanite + quartz, for which calculated peak pressure conditions are in good agreement with results obtained from eclogite samples. The eclogites contain a single population of spherical zircon with a low Th/U ratio. Combined constraints on the age of metamorphism come from U/Pb zircon as well as garnet-whole rock and mineral-mineral Sm-Nd analyses from eclogites. A coherent cluster of single zircon analyses yields a 206Pb/238U age of 90.7 plus or minus 1.0 Ma that is in good agreement with results from Sm-Nd garnet-whole rock regression of 90.7 plus or minus 3.9 and 90.1 plus or minus 2.0 Ma (epsilonNd: +8) for two eclogite samples. The agreement between U-Pb and Sm-Nd age data strongly suggests an age of approximately 90 Ma for the pressure peak of the eclogites in the Pohorje Mountains. The presence of garnet, omphacite and quartz inclusions in unfractured zircon indicates high-pressure rather than ultrahigh pressure conditions. The analysed metapelite sample yields a Sm-Nd garnet-hole rock scatterchron age of 97 plus or minus 15 Ma. These data probably support a single P-T loop for mafic and pelitic lithologies of the Pohorje area and a late Cretaceous high-pressure event that affected the entire easternmost Austroalpine basement including the Koralpe and Saualpe eclogite type locality in the course of the complex collision of the Apulian microplate and Europe. PUBLICATION ABSTRACT
In the Pohorje Mts, mostly outcrops of calcite marble can be found, which in places turn into dolomite marbles.The protolith carbonate rocks contained also detritical minerals, which remained ...unchanged or formed new mineralsduring metamorphosis. Minerals in the Pohorje marbles that can be seen as crystals with the naked eye or 10x magnifyingloupe and with binocular microscope were investigated. With the aid of Raman microspectroscopy, SEM-EDSanalysis and on the basis of morphological characteristics, the presence of 17 different minerals or group of mineralswas confirmed. The most numerous and also the most significant were, apart from calcite, tremolite, diopside, grossularand epidote. For the first time, vesuvianite and scapolite were described in the Pohorje Mts. Particularly rich, as faras crystal faces are concerned, were the crystals of quartz that contained needle-like amphiboles. Other minerals thatwell supplemented the mineral paragenesis were different minerals of mica and chlorite group, feldspars, magnetite,titanite, pyrite and graphite. The determined mineral association revealed the mineral diversity of Pohorje marbles,offering us a new challenge for the investigation of the characteristics and conditions during the origin of this noblerock, which was highly esteemed already by the Romans, while today it is regaining its value and recognisability.
Fluid inclusions in garnet combined with element X-ray mapping, phase equilibrium modelling and conventional thermobarometry have been used to constrain the metamorphic evolution of metapelitic ...gneiss from the HP/UHP metamorphic terrane of Pohorje Mountains in the Eastern Alps, Slovenia. Retrograde
P
–
T
trajectory from ~2.75 GPa and 780°C is constrained by the composition of matrix phengite (6.66 apfu Si) coexisting with garnet cores, kyanite and quartz. The intersection of the
X
Prp
= 0.25 isopleth for the garnet with the upper stability boundary for K-feldspar in the matrix indicates near-isothermal decompression to ~0.9 GPa at 720°C. Temperatures over 650°C during this stage are corroborated by the high degree of ordering of graphite inclusions associated with Zn, Mg-rich staurolite and phlogopite in the Mg-rich (
X
Prp
= 0.22–0.25) garnet cores. Majority of garnet porphyroblasts are depleted in Mg (down to
X
Prp
= 0.09) and enriched in Mn (up to
X
Sps
= 0.12) along cracks and at their margins. The associated retrograde mineral assemblage comprises Zn, Mg-poor staurolite, muscovite, biotite–siderophyllite, sillimanite and quartz. The onset of the retrogression and the compositional modification of the garnet porphyroblasts were accompanied by the addition of fluid-deposited graphite around older graphite inclusions, probably due to removal of water from a graphite-buffered COH fluid by dissolution in partial silicic melt. Instantaneous expulsion of water near the melt solidus (640°C, max. 0.45 GPa) caused dissolution of the graphite at redox conditions corresponding to 0.25–1.25 log
f
O
2
units below the QFM buffer, giving rise to a H
2
O–CO
2
–CH
4
fluid trapped in primary inclusions in Mn-rich, Mg-poor, almandine garnet that reprecipitated within the retrogressed domains. The absence of re-equilibration textures and consistent densities of the fluid inclusions reflect a near-isochoric cooling postdating the near-isothermal decompression. Bulk water content in the metapelite attained 2 wt% during this stage. The low-degree partial melting and extensive hydration due to the release of the internally derived, low-pressure aqueous fluids led to the reset of peak-pressure mineral assemblage.
Forest management has become increasingly complex since economic profit became only one of several important management objectives. Considering a diverse set of goals requires the use of ...multi-criteria decision making. When the only goal was to maximize timber production, the planning process often involved only one decision maker: the forest owner. We present the analytic hierarchy process as suitable multi-criteria method, which has been already applied in areas such as forestry and harvest scheduling, biodiversity conservation, regional planning, and forest sustainability. A case study of the forest area at Pohorje, a mountainous area in northern Slovenia, was conducted in order to implement the described theoretical findings. Th e aim of the study was to select the optimal alternative for Pohorje development. Th e results of the analysis show that the alternative benefits for people, which takes into account all of Pohorje's important aspects, is the most appropriate for Pohorje development.Original Abstract: Upravljanje sumama evaluiralo je u slozeniji zadatak, buduci da je ekonomska dobit samo jedna od nekoliko vaznih ciljeva upravljanja. Uvazavajuci tako razlicit skup ciljeva upravljanja, zahtijeva koristenje visekriterijske metode odlucivanja. Kada je maksimalna proizvodnja drva bila jedini cilj, odluke o planiranju procesa u vecini slucajeva donosio je vlasnik sume. Posljednjih dvadeset godina, proces planiranja se promijenio te ukljucuje interese vise zainteresiranih strana kao npr. lokalne zajednice, javne predstavnike, lovce, ekologe, rekreativce i druge. Oni imaju razlicita znanja, iskustva, perspektive i interese. Formiranje grupe treba se temeljiti na participativnom planiranju. Glavni problem grupnog odlucivanja je rjesavanje konflikta izmedu razlicitih ciljeva i preferencija. Grupiranje pojedinacnih preferencija nije samo matematicki vec i filozofski problem. U radu smo predstavili analiticki hijerarhijski proces kao prikladnu visekriterijsku metodu, koja se vec primjenjuje u podrucju sumarstva, planiranju zetve, ocuvanju bioloske raznolikosti, prostornom planiranju, odrzivosti suma i drugdje. Studija o sumskom podrucju Pohorja, planinskom lancu u sjevernoj Sloveniji, izvodi se prema opisanim teorijskim osnovama. Cilj naseg istrazivanja bio je izbor optimalne alternative za razvoj Pohorja. Identificirali smo pet mogucih alternativa na temelju pokazatelja odrzivosti. Alternative su usporedivali nekolicina zainteresiranih sudionika, prema rezultatima SWOT analize, koja je izvedena na radionici, gdje su sudionici raspravljali o pojedinim poglavljima scenarija o upravljanju sumama. Rezultati pokazuju da je alternativa "Dobrobiti za ljude", koja ukljucuje sva vazna gledista za Pohorje, najprikladnija za razvoj istog.
Nedavna geomorfološka raziskovanja na vzhodnem Pohorju so prinesla nova spoznanja o periglacialnih in ledeniških reliefnih oblikah na tem območju. Na podlagi teh ugotovitev so sledile raziskave ...podobnih pojavov na zahodnem Pohorju, predvsem krioplanacijskih teras in nivacijskih kotanj. Terenske raziskave so razkrile tudi obstoj potujočih skal, kamnitih tokov, blockmeerov in krnice pod Ribniškim jezerom.
The composition of mineral phases and their modal proportions have been determined for three representative Eoalpine eclogites from the Saualpe type locality/Eastern Austria (sample SKP31) and the ...Pohorje Massif/Slovenia (CM31/03 and CM15/01) using electron microprobe, laser ICP-MS, IR spectroscopy and modal analysis to evaluate possible mechanisms for the formation of composite oriented calcic amphibole
+
quartz inclusions (COIs) in omphacite and to assess the relative importance of hydrous and nominally anhydrous phases as H
2O carriers in these eclogites.
For omphacites in CM31/03 with a zonal distribution of COIs, a comparison of water and trace element concentrations of areas containing COIs and those free of COIs and a comparison with the trace element concentration of calcic amphibole indicate that COIs have formed through an open-system alteration of clinopyroxene and not through a closed system exsolution process. In sample SKP31, both textural and mineral chemical evidence suggests that COIs did not form by exsolution involving a Ca-Eskola component in clinopyroxene but formed by progressive growth under eclogite-facies P-T conditions and prior to the onset of retrogressive symplectite formation analogous to the formation of poikiloblastic quartz–calcic amphibole grains in the matrix.
Bulk H
2O contents of the eclogites are between ca. 750 and 2150 ppm with 6–25% of the total water contributed by nominally anhydrous minerals (NAMs). Because of high modal amounts of 37–65%, omphacite is the major nominally anhydrous water carrier, containing 145–580 ppm H
2O with significant concentration variations on a thin section scale. Due to their very low H
2O concentrations of <
5–10 ppm (garnet, kyanite) or insignificant modal amounts ≤
3% (rutile) the remaining NAMs contribute less than 1.5% to the bulk eclogite H
2O content. Calcic amphibole forming part of COIs may be a major carrier of H
2O as evidenced by CM31/03 containing both COIs and texturally primary calcic amphibole. In this sample calcic amphibole of the COIs contributes 63% whereas primary calcic amphibole only accounts for 13% of the bulk water. The relative order of H
2O concentrations in NAMs is H
2O
rutile
>
H
2O
omphacite
≫
H
2O
garnet for CM31/03 and CM15/01 and H
2O
rutile
≈
H
2O
omphacite
≫
H
2O
garnet in SKP31.
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