Friedrich Koller

Comparison of the element composition in several plant species and their substrate from a 1 500 000-km2 area in Northern Europe

Leaves of 9 different plant species (terrestrial moss represented by: Hylocomium splendens and Pleurozium schreberi; and 7 species of vascular plants: blueberry, Vaccinium myrtillus; cowberry, Vaccinium titis-idaea; crowberry, Empetrum nigrum; birch, Betula pubescens; willow, Salix spp.; pine, Pinus sylvestris and spruce, Picea abies) have been collected from up to 9 catchments (size 14-50 km2) spread over a 1500000 km2 area in Northern Europe. Soil samples were taken of the O-horizon and of the C-horizon at each plant sample site. All samples were analysed for 38 elements (Ag, Al, As, B, Ba, Be, Bi, Ca, Cd, Co, Cr, Cu, Fe, Hg, K, Li, Mg, Mn, Mo, Na, Ni, P, Pb, Rb, S, Sb, Sc, Se, Si, Sn, Sr, Th, Tl, U, V, Y, Zn and Zr) by ICP-MS, ICP-AES or CV-AAS (for Hg-analysis) techniques. The concentrations of some elements vary significantly between different plants (e.g. Cd, V, Co, Pb, Ba and Y). Other elements show surprisingly similar levels in all plants (e.g. Rb, S, Cu, K, Ca, P and Mg). Each group of plants (moss, shrubs, deciduous and conifers) shows a common behaviour for some elements. Each plant accumulates or excludes some selected elements. Compared to the C-horizon, a number of elements (S, K, B, Ca, P and Mn) are clearly enriched in plants. Elements showing very low plant/C-horizon ratios (e.g. Zr, Th, U, Y, Fe, Li and Al) can be used as an indicator of minerogenic dust. The plant/O-horizon and O-horizon/C-horizon ratios show that some elements are accumulated in the O-horizon (e.g. Pb, Bi, As, Ag, Sb). Airborne organic material attached to the leaves can thus, result in high values of these elements without any pollution source.

Influence of extreme pollution on the inorganic chemical composition of some plants

Leaves of nine different plant species (terrestrial moss: Hylocomium splendens and Pleurozium schreberi, blueberry: Vaccinium myrtillus, cowberry: Vaccinium vitis-idaea, crowberry: Empetrum nigrum, birch: Betula pubescens, willow: Salix spp., pine: Pinus sylvestris, and spruce: Picea abies) have been collected from up to nine catchments (size 14-50 km2) spread over a 1,500,000 km2 area in northern Europe. Additional soil samples were taken from the O-horizon and the C-horizon at each plant sample site. All samples were analysed for 38 elements (Ag, Al, As, B, Ba, Be, Bi, Ca, Cd, Co, Cr, Cu, Fe, Hg, K, Li, Mg, Mn, Mo, Na, Ni, P, Pb, Rb, S, Sb, Sc, Se, Si, Sn, Sr, Th, Tl, U, V, Y, Zn, and Zr) by ICP-MS, ICP-AES or CV-AAS (Hg) techniques. One of the 9 catchments was located directly adjacent (5-10 km S) to the nickel smelter and refinery at Monchegorsk, Kola Peninsula, Russia. The high levels of pollution at this site are reflected in the chemical composition of all plant leaves. However, it appears that each plant enriches (or excludes) different elements. Elements emitted at trace levels, such as Ag, As and Bi, are relatively much more enriched in most plants than the major pollutants Ni, Cu and Co. The very high levels of SO2 emissions are generally not reflected by increases in plant total S-content. Several important macro-(P) and micro-nutrients (Mn, Mg, and Zn) are depleted in most plant leaves collected near Monchegorsk.

The Jurassic South Albanian ophiolites: MOR- vs. SSZ-type ophiolites

Abstract Within the western belt of the southern Albanian ophiolites, the Voskopoja ophiolite consists of three subunits: Voskopoja, Morava and Rehove. These are predominantly lherzolites with minor harzburgites and dunites in the mantle section. Above come ultramafic and mafic cumulates including wehrlites, troctolites and olivine gabbros. Gabbronorites are restricted to the Morava subunit. Isotropic clinopyroxene gabbros, extrusives and sediments are present only in Rehove and Voskopoja. The volcanic section is dominated by basaltic breccias, including megablocks with sheeted dykes, pillow lavas and isolated dykes. The basaltic breccias grade upwards into sandstones, in turn, interlayered with argillites and cherts of Jurassic age. The basalts are predominantly clinopyroxene–plagioclase basalts, either aphyric or plagioclase phyric. Geochemically, they are divided into four groups: (1) an intermediate Ti and Zr group with low Ni (hereafter called low-Ni group), (2) an intermediate Ti–Zr group with high Ni (hereafter called high-Ni group), (3) a high-Ti–Zr group and (4) a low-Ti–Zr group. The high-Ni content in group 2 is interpreted as originating from olivine and spinel xenocrysts. Apart from the high-Ni content, groups 1 and 2 are comparable with the volcanics of the “low- to high-Ti intermediate ophiolites.” By contrast, group 3 is more comparable to the high-Ti ophiolitic extrusives in the western ophiolite belt of northern Albania. Group 4 consists SSZ-type basalts and is widespread in the volcanics of the eastern ophiolite belt. Comparison of the ultramafic–mafic cumulates and the basaltic volcanics with those in the northern part of the western belt in Albania and the Pindos ophiolite indicates that there is a systematic variation in petrography and geochemistry from north to south in the western belt, with an increasingly distinct SSZ signature towards the south. Ultramafic and mafic cumulates, as well as basalts from the Shebenik massif in the eastern belt, are similar to those of Voskopoja, implying a genetic relationship.

Metamorphism of metasediments at the scale of an orogen: a key to the Tertiary geodynamic evolution of the Alps*

Abstract Major discoveries in metamorphic petrology, as well as other geological disciplines, have been made in the Alps. The regional distribution of Late Cretaceous–Tertiary metamorphic conditions, documented in post-Hercynian metasediments across the entire Alpine belt from Corsica–Tuscany in the west to Vienna in the east, is presented in this paper. In view of the uneven distribution of information, we concentrate on type and grade of metamorphism; and we elected to distinguish between metamorphic paths where either pressure and temperature peaked simultaneously, or where the maximum temperature was reached at lower pressures, after a significant temperature increase on the decompression path. The results show which types of process caused the main metamorphic imprint: a subduction process in the western Alps, a collision process in the central Alps, and complex metamorphic structures in the eastern Alps, owing to a complex geodynamic and metamorphic history involving the succession of the two types of process. The western Alps clearly show a relatively simple picture, with an internal (high-pressure dominated) part thrust over an external greenschist to low-grade domain, although both metamorphic domains are structurally very complex. Such a metamorphic pattern is generally produced by subduction followed by exhumation along a cool decompression path. In contrast, the central Alps document conditions typical of subduction (and partial accretion), followed by an intensely evolved collision process, often resulting in a heating event during the decompression path of the early-subducted units. Subduction-related relics and (collisional/decompressional) heating phenomena in different tectonic edifices characterize the Tertiary evolution of the Eastern Alps. The Tuscan and Corsica terrains show two different kinds of evolution, with Corsica resembling the western Alps, whereas the metamorphic history in the Tuscan domain is complex owing to the late evolution of the Apennines. This study confirms that careful analysis of the metamorphic evolution of metasediments at the scale of an entire orogen may change the geodynamic interpretation of mountain belts.

Geochemistry and tectonic setting of magmatic units in the Pan-African Gariep Belt, Namibia

Abstract Major-, trace-, rare-earth-element, and RbSr and SmNd isotope data of the various low-grade metamorphosed magmatic units in the Pan-African Gariep Belt, southwestern Namibia, presented in this paper, provide the basis for the reconstruction of the evolution of the late Proterozoic Adamastor ocean between the South American and Kalahari Cratons. The Gariep Belt is subdivided into two major zones, a para-autochthonous, predominantly sedimentary rift and passive continental margin succession (Port Nolloth Zone, PNZ) and the allochthonous, predominantly mafic Marmora Terrane. The latter has been thrust in southeasterly direction over the former. All of the magmatic activity in the PNZ can be related to lithospheric stretching. The earliest magmatic activity is expressed as bimodal volcanism with continental within-plate affinity along an embryonic rift graben (Rosh Pinah Formation) and is found within the older sediment package of the para-autochthonous external zone of the orogen. After ∼ 24 Ma, this was followed by the intrusion of mafic, tholeftic dykes into the basement and the lower parts of the PNZ, heralding the opening of the Gariepian basin at 717 Ma. There is evidence of a series of seamounts, or an aseismic ridge, with oceanic within-plate characteristics in the Marmora Terrane. Such volcanic piles make up most of the Schakalsberge Complex and parts of the Chameis Complex. Both complexes are separated by turbidites (Oranjemund Complex), which are interpreted as continental slope deposits. In the Chameis Complex, metagabbros predominate. Most of them are part of the oceanic seamounts, but some have a markedly different chemistry, indicative of a mid-ocean ridge setting. During Pan-African collision, the Marmora Terrane formed an accretionary wedge that was thrust over the passive continental margin succession. Peak metamorphism in the thickened crust was reached at ∼ 545 Ma, with erosion of the orogen having commenced as early as 540 Ma.

Element levels in birch and spruce wood ashes — green energy?

Production of wood ash has increased strongly in the last ten years due to the increasing popularity of renewable and CO(2)-neutral heat and energy production via wood burning. Wood ashes are rich in many essential plant nutrients. In addition they are alkaline. The idea of using the waste ash as fertiliser in forests is appealing. However, wood is also known for its ability to strongly enrich certain heavy metals from the underlying soils, e.g. Cd, without any anthropogenic input. Concentrations of 26 chemical elements (Ag, As, Au, B, Ba, Ca, Cd, Co, Cr, Cu, Fe, Hg, K, La, Mg, Mn, Mo, Na, Ni, P, Pb, S, Sb, Sr, Ti, and Zn) in 40 samples each of birch and spruce wood ashes collected along a 120 km long transect in southern Norway are reported. The observed maximum concentrations are 1.3 wt.% Pb, 4.4 wt.% Zn and 203 mg/kg Cd in birch wood ashes. Wood ashes can thus contain very high heavy metal concentrations. Spreading wood ashes in a forest is a major anthropogenic interference with the natural biogeochemical cycles. As with the use of sewage sludge in agriculture the use of wood ashes in forests clearly needs regulation.

ReOs isotopes in orogenic peridotite massifs in the Eastern Alps, Austria

The ReOs and SmNd isotopic systematics of polymetamorphic massif peridotite bodies, which have been described as ophiolites, are examined. The serpentinized mantle rocks from different tectonic units of the Eastern Alps reveal that Os isotopes are robust and provide information that field studies, petrographic and major and trace element studies do not. Presumed Paleozoic (e.g., Kraubath and Hochgrossen) and Mesozoic (e.g., Reckner Complex) bodies have uniform 187Os/188Os ratios that are slightly higher than, but within the range of, abyssal peridotites, which are presumed to represent the depleted mid-ocean ridge basalt source mantle (DMM). One serpentinite from the Penninic unit yields 187Os/188OS much lower than DMM. This mantle rock must have had a source in a long-term Re-depleted reservoir of the upper mantle. Although our understanding of the ReOs isotope system of upper mantle reservoirs is still limited, this system can be used to help constrain the tectonic evolution of diverse terrains.

U–Pb and Sm–Nd geochronology of the Kızıldağ (Hatay, Turkey) ophiolite: implications for the timing and duration of suprasubduction zone type oceanic crust formation in the southern Neotethys

The Kizildag (Hatay) ophiolite in Turkey represents remnants of the southern Neotethyan ocean and is characterized by a complete ocean lithospheric section. It formed in a fore-arc setting above a N-dipping intraoceanic subduction zone, and represents the undeformed, more northerly part of the same thrust sheet that also forms the Baer–Bassit ophiolite to the south. The ophiolite was emplaced southwards from the southerly Neotethyan ocean in Maastrichtian time. U–Pb and Sm–Nd dates are used to constrain the crystallization age and duration of magmatic activity of the Kizildag ophiolite. U–Pb dating yielded ages of 91.7 ± 1.9 Ma for a plagiogranite and 91.6 ± 3.8 Ma for a cumulate gabbro. The cumulate gabbro also yielded a Sm–Nd isochron age of 95.3 ± 6.9 Ma. The measured ages suggest that the oceanic crust of the Kizildag ophiolite formed in a maximum time period of 6 Ma, and that the plagiogranite may have formed later than the gabbroic section. The U–Pb zircon ages from the Kizildag ophiolite and the cooling age of a metamorphic sole beneath the Baer–Bassit ophiolite are indistinguishable within the analytical uncertainties. This indicates the presence of young and hot oceanic lithosphere at the time of intraoceanic subduction/thrusting in the southern Neotethys. The U–Pb zircon ages from the Kizildag, the Troodos and the Semail ophiolites overlap within analytical uncertainties, suggesting that these ophiolites are contemporaneous and genetically and tectonically related within the same Late Cretaceous southern Neotethyan ocean.

Cumulates and gabbros in southern Albanian ophiolites: their bearing on regional tectonic setting

Abstract The western belt of the southern Albanian ophiolites consists of six major ophiolite massifs (Voskopoja, Rehove, Morava, Devolli, Vallamara, Shpati) and two smaller ones (Luniku and Stravaj). Each massif has a distinct sequence of mantle tectonites, ultramafic cumulates (plagioclase-bearing peridotites and wehrlites), cumulate gabbros, troctolites and isotropic gabbros. Voskopoja, Rehove and Morava have predominantly lherzolites as mantle tectonites, Shpati lherzolites and harzburgites, and Devolli and Vallamara almost exclusively harzburgites. A volcanic section together with volcanogenic sediments occurs only in the Voskopoja and Rehove massifs as well as in the smaller Luniku and Stravaj massifs. Whole-rock geochemistry and mineral chemistry suggest a mid-ocean ridge setting for the origin of the cumulates and gabbros from the Voskopoja, Rehove and Morava massifs, with only a minor suprasubduction zone (SSZ) influence. The Shpati massif and the small Luniku massif show mid-ocean ridge (MOR) and SSZ signatures in their plutonic sequences. Cumulates and gabbros from Devolli and Vallamara formed in an SSZ setting. The predominance of MOR-generated crustal rocks and the relatively minor occurrence of SSZ-generated plutonic rocks together with the volcanogenic sediments in the Voskopoja and Rehove massifs are indicative of a back-arc basin origin of the western belt ophiolites above a westward-dipping subduction zone.

Magmatic evolution of the Suqii-Wagga garnet-bearing two- mica granite, Wallagga area, western Ethiopia

The Suqii-Wagga two-mica granite, situated in the western Ethiopian Precambrian, is emplaced in a high-grade migmatitic terrane. It is composed of feldspars + quartz + muscovite + biotite ± garnet + zircon ± allanite ± apatite + Fe-Ti oxides + Fe sulphide. Textural studies and microprobe analyses revealed two generations of almandine-spessartine-rich magmatic garnet. The first is euhedral, fine-grained (300–350 μm), commonly occurs as inclusions in plagioclase and alkali feldspars, and exhibits chemical zoning with almandine-rich cores and spessartine-rich rims. In contrast, the second variety is medium- to coarse-grained (1–7 mm) and shows reverse zoning with spessartine-rich cores and almandine-rich rims. Primary and secondary muscovites were discriminated based on the concentrations of Ti, Fe, Mn and Na. Biotite is characterised by a higher alumina saturation index than biotites of other granitoids in the area, suggesting considerable alumina concentration in the source magma. Garnet-biotite thermometry and phengite barometry were used to estimate the P-T conditions of crystallisation for the Suqii-Wagga two-mica granite pluton at ∼ 7 kbar and ∼ 670°C. Mineral paragenesis, the composition of aluminous minerals and the P-T conditions of crystallisation indicate that samples containing fine-grained garnet crystallised earlier than those containing medium- to coarse-grained garnet. Field and petrographic investigations, mineral chemistry, and whole rock major and trace element studies suggest that the Suqii-Wagga two-mica granite has the characteristics of anatectic granite. Highly variable normative Ab/Or ratios suggested melting under varying aH2O conditions and/or source characteristics. The relatively high Rb/Sr, Rb/Ba and low CaO/Na2O (<0.3) ratios indicate the derivation of the granitic magma from a plagioclase-poor pelitic source. Moreover, pronounced negative Eu anomalies and large ion lithophile element modelling suggested crystal fractionation involving plagioclase. The presence of the Suqii-Wagga Granite Pluton implies a significant contribution of older mature crustal material to the magmatic evolution of the area.