214 research outputs found
Alles nur symbolisch? Bilanz und Perspektiven der Erforschung symbolischer Kommunikation
No full textBrauner C, Stollberg-Rilinger B, Neu T, eds. Alles nur symbolisch? Bilanz und Perspektiven der Erforschung symbolischer Kommunikation. Köln u.a.: Böhlau; 2013
Eine Frage von Herrschaft: Religion und Geschlecht im alten Rom
No full textHarders A-C. Eine Frage von Herrschaft: Religion und Geschlecht im alten Rom. In: Stollberg-Rilinger B, ed. „Als Mann und Frau schuf er sie“. Religion und Geschlecht. Religion und Politik. Vol 7. Würzburg: Ergon; 2014: 17-45
Magnetite as a provenance and exploration tool to metamorphosed base metal sulfide deposits in the Stollberg ore field, Bergslagen, Sweden
No full textMagnetite is a common mineral in the Paleoproterozoic Stollberg Zn–Pb–Ag plus magnetite ore field (~6.6 Mt of production), which occurs in 1.9 Ga metamorphosed felsic and mafic rocks. Mineralisation at Stollberg consists of magnetite bodies and massive to semi-massive sphalerite–galena and pyrrhotite (with subordinate pyrite, chalcopyrite, arsenopyrite and magnetite) hosted by metavolcanic rocks and skarn. Magnetite occurs in sulfides, skarn, amphibolite and altered metamorphosed rhyolitic ash–siltstone that consists of garnet–biotite, quartz–garnet–pyroxene, gedrite–albite, and sericitic rocks. Magnetite probably formed from hydrothermal ore-bearing fluids (~250–400°C) that replaced limestone and rhyolitic ash–siltstone, and subsequently recrystallised during metamorphism. The composition of magnetite from these rock types was measured using electron microprobe analysis and LA–ICP–MS. Utilisation of discrimination plots (Ca+Al+Mn vs. Ti+V, Ni/(Cr+Mn) vs. Ti+V, and trace-element variation diagrams (median concentration of Mg, Al, Ti, V, Co, Mn, Zn and Ga) suggest that the composition of magnetite in sulfides from the Stollberg ore field more closely resembles that from skarns found elsewhere rather than previously published compositions of magnetite in metamorphosed volcanogenic massive sulfide deposits. Although the variation diagrams show that magnetite compositions from various rock types have similar patterns, principal component analyses and element–element variation diagrams indicate that its composition from the same rock type in different sulfide deposits can be distinguished. This suggests that bulk-rock composition also has a strong influence on magnetite composition. Principal component analyses also show that magnetite in sulfides has a distinctive compositional signature which allows it to be a prospective pathfinder mineral for sulfide deposits in the Stollberg ore field.This article is published as Frank, Katherine S., Paul G. Spry, Joshua J. O'Brien, Alan Koenig, Rodney L. Allen, and Nils Jansson. "Magnetite as a provenance and exploration tool to metamorphosed base metal sulfide deposits in the Stollberg ore field, Bergslagen, Sweden." Mineralogical Magazine 86 (2022): 373-396. doi:https://doi.org/10.1180/mgm.2022.39
Geological, mineralogical, and geochemical studies of the Paleoproterozoic base metal Stollberg ore field, Bergslagen, Sweden
No full textThe Stollberg ore field (~12 Mt) occurs in the Bergslagen region of south-central Sweden, a polydeformed ca. 1.9 Ga igneous province dominated by bimodal felsic and mafic rocks. Sulfide mineralization is hosted by metavolcanic rocks, marble, and skarn, and consists of massive to semi-massive polymetallic sulfides and iron oxide in a semi-regional F2 syncline termed the “Stollberg syncline.” The dominant country rocks are rhyolitic pumice breccia and rhyolitic ash-siltstone with minor mafic sills metamorphosed to the amphibolite facies. On the eastern limb of the Stollberg syncline, sulfide mineralization occurs as stratabound replacement of marble/skarn that grades into iron formation spatially related to metamorphosed, hydrothermally altered rocks dominated by garnet-biotite and gedrite-albite. Although silicified rocks are generally subordinate in the Stollberg ore field, sulfides at Grà ¤nsgruvan, on the western limb of the syncline, are located in a silicified zone along with metamorphosed, altered rocks dominated by sericite and quartz-garnet-pyroxene. Although the Tvistbo and Norrgruvan prospects along the northern end of the syncline are small, they show geological characteristics that are transitional to deposits found on the western and eastern limbs of the syncline. Ore at Tvistbo is hosted by skarn and is also spatially associated with quartz-garnet-pyroxene rocks, whereas sulfides at Norrgruvan are hosted by quartz-fluorite altered rocks that are similar to those hosting the Brusgruvan deposit on the eastern limb of the syncline.
Whole-rock analyses of variably altered host rocks in the Stollberg ore field suggest that most components were derived from felsic volcaniclastic rocks and that Zr, Ti, Al, Hf, Nb, Sc, Th, Ga, U, and rare-earth elements (REEs) were immobile during alteration. These rocks (including altered rocks in the stratigraphic footwall) are light REE enriched, heavy REE depleted, and show negative Eu anomalies, whereas sulfide-bearing rocks (Fe- and base metal-rich) and altered rocks in the ore zone show the same REE pattern but with positive Eu anomalies.
Indicators of proximity to sulfides in altered rocks in the Stollberg ore field include positive Eu anomalies, an increase in the concentration of Pb, Sb, As, Tl, Ba, Ba/Sr and K2O, as well as an increase in a modified version of the Ishikawa alteration index, which accounts for the presence of primary Ca in an original limestone component. In addition, garnets enriched in either Ca or Mn as well as principal component analyses of magnetite in sulfide mineralization are also considered to be pathfinders to ore.
Magnetite occurs in sulfides, skarn, amphibolite, and altered metamorphosed rhyolitic ash-siltstone that consists of garnet-biotite, quartz-garnet-pyroxene, gedrite-albite, and sericitic rocks. Magnetite was derived from hydrothermal fluids (~250˚ – 400˚ C) that replaced limestone and rhyolitic ash-siltstone, and subsequently recrystallized during metamorphism. Utilization of discrimination plots (Ca+Al+Mn vs. Ti+V, Ni/(Cr+Mn) vs. Ti+V, Al/(Zn+Ca) vs. Cu/(Si+Ca)) and spider diagrams (median concentration of Mg, Al, Ti, V, Co, Mn, Zn and Ga) suggest that magnetite compositions in sulfides from the Stollberg ore field more closely resemble those from skarns found elsewhere rather than from metamorphosed volcanogenic massive sulfide deposits. Although spider diagrams show that magnetite compositions from various rocks types have similar patterns, suggesting that its formation was associated with a high water to rock ratio, principal component analyses indicate that the composition of magnetite from the same rock type in different sulfide deposits can be distinguished. This suggests that bulk rock composition also has a strong influence on magnetite chemistry.</p
Magnetite as a provenance and exploration tool to metamorphosed base-metal sulfide deposits in the Stollberg ore field, Bergslagen, Sweden
No full textMagnetite is a common mineral in the Paleoproterozoic Stollberg Zn–Pb–Ag plus magnetite ore field (~6.6 Mt of production), which occurs in 1.9 Ga metamorphosed felsic and mafic rocks. Mineralisation at Stollberg consists of magnetite bodies and massive to semi-massive sphalerite–galena and pyrrhotite (with subordinate pyrite, chalcopyrite, arsenopyrite and magnetite) hosted by metavolcanic rocks and skarn. Magnetite occurs in sulfides, skarn, amphibolite and altered metamorphosed rhyolitic ash–siltstone that consists of garnet–biotite, quartz–garnet–pyroxene, gedrite–albite, and sericitic rocks. Magnetite probably formed from hydrothermal ore-bearing fluids (~250–400°C) that replaced limestone and rhyolitic ash–siltstone, and subsequently recrystallised during metamorphism. The composition of magnetite from these rock types was measured using electron microprobe analysis and LA–ICP–MS. Utilisation of discrimination plots (Ca+Al+Mn vs. Ti+V, Ni/(Cr+Mn) vs. Ti+V, and trace-element variation diagrams (median concentration of Mg, Al, Ti, V, Co, Mn, Zn and Ga) suggest that the composition of magnetite in sulfides from the Stollberg ore field more closely resembles that from skarns found elsewhere rather than previously published compositions of magnetite in metamorphosed volcanogenic massive sulfide deposits. Although the variation diagrams show that magnetite compositions from various rock types have similar patterns, principal component analyses and element–element variation diagrams indicate that its composition from the same rock type in different sulfide deposits can be distinguished. This suggests that bulk-rock composition also has a strong influence on magnetite composition. Principal component analyses also show that magnetite in sulfides has a distinctive compositional signature which allows it to be a prospective pathfinder mineral for sulfide deposits in the Stollberg ore field.</p
Unusual formation of a N-heterocyclic germylene via homolytic cleavage of a C-C bond
No full textDeutsche Forschungsgemeinschaft [RO 224/60-1]; Danish National Research Foundation [DNRF93]; Centre for Materials Crystallography; Norwegian Research Council through the CoE Centre for Theoretical and Computational Chemistry (CTCC) [179568/V30]; China Scholarship Council; Norwegian Supercomputing Program (NOTUR) [NN4654K]Reaction of the monoanionic radical salt IP center dot-K+ (IP = (Py)CH(=NR); Py = C5H4N, R = 2,6-iPr(2)C(6)H(3); alpha-iminopyridine) with GeCl2(dioxane) afforded compound (IPGeCl)(2) (1) which produced red blocks of IPGe: (2), when treated with KC8 in toluene. 1 is a digermylene formed via C-C coupling between two carbon-centered radicals. 2 can be considered as an analogue of a N-heterocyclic carbene, which exhibits a five-membered GeC2N2 ring with one CQC double bond. 2 is formed by two-electron reduction of 1 with cleavage of the two Ge-Cl bonds and the central C-C single bond
Size-selective colloidal-gold localization in transmission X-ray microscopy
No full textColloidal gold is a useful marker for functional-imaging experiments in transmission X-ray microscopy. Due to the low contrast of gold particles with small diameters it is necessary to develop a powerful algorithm to localize the single gold particles. The presented image-analysis algorithm for identifying colloidal gold particles is based on the combination of a threshold with respect to the local absorption and shape discrimination, realized by fitting a Gaussian profile to the identified regions of interest. The shape discrimination provides the possibility of size-selective identification and localization of single colloidal gold particles down to a diameter of 50 nm. The image-analysis algorithm, therefore, has potential for localization studies of several proteins simultaneously and for localization of fiducial markers in X-ray tomography
A stable isotope (S, C and O) study of metamorphosed polymetallic sulphide deposits in the Bergslagen district, Sweden: The Stollberg example
No full textThe Paleoproterozoic Stollberg Zn-Pb-Ag plus magnetite ore field contains SVALS-type stratabound, limestone-skarn hosted sulphide deposits within volcanic (bimodal felsic and mafic rocks)/volcaniclastic rocks metamorphosed to the amphibolite facies. The sulphide ores consist of semi-massive to disseminated to vein-network sphalerite-galena and pyrrhotite (with subordinate pyrite, chalcopyrite, arsenopyrite and magnetite). Thermochemical considerations and stabilities of minerals in the systems K-Al-Si-O-H and Fe-S-O and sulphur isotope values for sulphides of δ34SVCDT = +1.12 to +5.71 ‰ suggest that sulphur most likely formed by inorganic reduction of seawater sulphate that was carried in hydrothermally modified seawater fluid under the following approximate physicochemical conditions: T = 250o–350 oC, δ34SΣS = +3 ‰, I = ∼1 m NaCl and a total dissolved S content of ∼0.01 to 0.1 moles/kg H2O. However, a magmatic contribution of sulphur cannot be discounted. Carbon and oxygen isotope compositions of calcite in altered rocks spatially associated with mineralisation show values of δ13CVPDB = −2.3 to −0.8 ‰ and δ18OVSMOW = +9.5 to +11.2 ‰, with one anomalous sample exhibiting values of δ13CVPDB = −0.1 ‰ and δ18OVSMOW = +10.9 ‰. Most carbonates in ore show lighter C and O isotope values than those of Proterozoic (Orosirian) limestones and are likely the result of premetamorphic hydrothermal alteration involving modified seawater followed by decarbonation during regional metamorphism. The isotopically light C and O isotope values are consistent with those for carbonates spatially associated with other SVALS-type deposits in the Bergslagen ore district and suggest that such values may be used for exploration purposes.This article is published as Spry PG, Jansson NF, Allen RL. A stable isotope (S, C and O) study of metamorphosed polymetallic sulphide deposits in the Bergslagen district, Sweden: The Stollberg example. Geological Magazine. 2024;161:e16. doi:10.1017/S001675682400015
Auf das frühzeitige Absterben der Hochgebohrnen Reichsgräfin und Fraun Fraun Sophien Augusten von Hoym geb. Reichsgräfin zu Stollberg [et]c. von denen sämmtlichen Stift-Naumburgischen Cammer-Officianten : Jm Jahr 1776
No full textTrauergedicht auf Frau Sophie Auguste von Hoym, geb. Reichsgräfin zu Stollberg[Johann Friedrich Teller]Vorlageform des Erscheinungsvermerks: Leipzig, gedruckt bey Johann Friedrich Langenheim
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