Frank Haubrich

Der Steinbruch am Flügel Jägerhorn westlich von Grillenburg ist vermutlich der älteste Kreidesandsteinbruch des Tharandter Waldes, in Betrieb seit etwa 1170. Historisch belegt ist, dass beispielsweise 1225 die Goldene Pforte des Freiberger St.-Marien-Doms aus Grillenburger Sandstein gefertigt wurde. Die vom Universalgelehrten J.F. Henckel (1722) veröffentlichten Kupferstiche der fossilen Hahnenkamm-Muschel Rastellum carinatum und der Pectinide Merklinia aspera aus dem „Sandsteinbruche im Grüllenburger Walde“ sind in der Literatur die bisher ältesten bekannten Abbildungen von sächsischen Kreide-Fossilien. Im Sandsteinbruch am Flügel Jägerhorn ist als unterster Abschnitt die über 5 m mächtige „Werksteinbank“ aufgeschlossen, der marine Werksandstein der oberen Oberhäslich-Formation (unteres Obercenomanium), der fälschlicherweise in den letzten über 130 Jahren der kontinentalen Niederschöna-Formation (Untercenomanium) zugeordnet und als fossilfreier Dünensandstein interpretiert wurde. D...

According to the theory of plate tectonics, rocks found in the vicinity of mid-ocean ridges - where oceanic plates are created - should be relatively young (at most several Myr old). Here we report the discovery of zircons with ages of about 330 and 1,600 Myr that were drilled from exposed gabbros beneath the Mid-Atlantic Ridge near the Kane fracture zone (Cannat and ODP Shipboard Scientific Party, 1995; Werner, 1997, doi:10.2973/odp.proc.sr.153.031.1997; Werner and Pilot, 1997, doi:10.2973/odp.proc.sr.153.018.1997; Pilot et al., 1996). Age determinations were made using the 207Pb/206Pb evaporation method (Kober, 1987, doi:10.1007/BF00375526) and confirmed with conventional U–Pb dating and ion microprobe (SHRIMP) analysis. We suggest two plausible explanations for the origin of these unusually old zircons. During the opening of the Atlantic, sheared crustal material or delaminated continental lithosphere sank into small roll-like circulation cells (Nocolas, 1995; Rabinowicz et al., ...

The importance of rare elements, especially for the industry sector of renewable energies is well known. Our research group collaborates with a Chilean company that leaches ore using the method of conventional heap leaching with sulfuric acid to extract copper. The dumped residuals of the leaching process have been investigated for their potential concerning the content of strategic elements. Strategic elements in this context are minor and trace elements of economic interest. One important question is whether these elements are recoverable by using simple and inexpensive processes.

After a long time of dumping, tailings are characterized by hydrogeochemical reorganization processes that are reflected in weathering zones (mobilization) and accumulation zones (immobilization). These processes are connected to substantial secondary mineral formation. Accumulation zones are thereby often connected to iron phases and also have an increased content of trace elements. This knowledge is relevant for Chilean mining dumps because some of them are already affected by these long time processes. Chilean mining companies are interested in information on the occurrence and extractability of secondary minerals and strategic elements (minor and trace elements of economic interest) from tailings. The German-Chilean project SecMinStratEl (Secondary Mining of Strategic Elements) aims to provide an understanding of the accumulation processes and will also evaluate opportunities for selective extraction. The project is actively supported by significant Chilean mining companies and ...

To increase resource efficiency, mining residues–especially tailings–have come into the focus of research, companies, and politics. Tailings still contain varying amounts of unextracted elements of value and minerals that were not of economic interest during production. As for primary mineral deposits, only a small share of tailings offers the possibility for an economic reprocessing. To minimize exploration expenditure, a stepwise process is followed during exploration, to estimate the likelihood of a project to become a mine or in this case a reprocessing facility. During this process, costs are continuously estimated at least in an order of magnitude. Reprocessing flowsheets for copper mine tailings in Chile were developed and costs and revenues of possible products from reprocessing were examined for a rough economic assessment. Standard cost models with capex and opex for flotation, leaching, and magnetic separation were adopted to the needs of tailings reprocessing. A copper t...

The leaching of manganese (Mn) ore in sulphuric acid (H2SO4) under reductive conditions has been studied. The effects of leaching parameters such as ore/reductant mass ratio, acid concentration, ore particle size, solid/liquid ratio, leaching time and different reductant potential on the maximum recovery of manganese have been investigated. The optimal leaching conditions were ore/reductant mass ratio of 1:3.4, acid concentration of 10% v/v H2SO4, ore particle size of 63-200 µm, particle size of iron powder of –150 µm, solid/liquid ratio of 1:20, and leaching time of 1.5 hours at room temperature. A comparative analysis on the recovery of manganese ore was also investigated under the optimal leaching conditions for two different reductants, iron sulphate (FeSO4) and iron powder. The maximum manganese recoveries at the optimal leaching conditions in the presence of FeSO4 and iron powder are 80.6% and 95%, respectively. The results indicate that manganese can readily be leached during...

The isotopic composition of air-borne sulphur was investigated in Saxony, Southeast Germany – a region with formerly very high atmospheric SO2 concentrations. In addition, data from various authors were compiled for different Saxonian locations, spanning from 1992 to 2004, i.e., a time of decreasing SO2 concentrations in the atmosphere. There were no obvious temporal changes in the mean δS value

ABSTRACT According to the theory of plate tectonics, rocks found in the vicinity of mid-ocean ridges - where oceanic plates are created - should be relatively young (at most several Myr old). Here we report the discovery of zircons with ages of about 330 and 1,600Myr that were drilled from exposed gabbros beneath the Mid-Atlantic Ridge near the Kane fracture zone. Age determinations were made using the 207Pb/206Pb evaporation method and confirmed with conventional U-Pb dating and ion microprobe (SHRIMP) analysis. We suggest two plausible explanations for the origin of these unusually old zircons. During the opening of the Atlantic, sheared crustal material or delaminated continental lithosphere sank into small roll-like circulation cells, that developed in the shallow mantle at each side of the ridge axis and the material was then transported through these cells to the ridge axis. Alternatively, material from the continental crust has been trapped within the Kane fracture zone since the opening of the Atlantic Ocean basin through a series of transform migrations and ridge jumps,, with portions of this material subsequently migrating down the ridge axis.

At Wurgwitz near Dresden, Saxony, Germany, a quarry was opened recently to retrieve material from the “Wilsdruff-Potschappel Porphyrite”. This Permo-Carboniferous, latitic-andesitic lava flow shows intensive alter-ation features in its upper sections. The material is dissected ...

... The core area of the ecosystem study, the RBSF (3 ° 58' 30" S and 79 ° 4' 25" W, about 11.2 km2), is located halfway between the province capitals Loja and Zamora in the deeply incised valley of the eponymous river (Fig. 1.2). ... E. Beck et al. ...

ABSTRACT There are few studies investigating the different carbon pools and fluxes of tropical soils. Even more restricted is our knowledge of tropical mountain forest soils that cover about 11% of the total tropical forest area (Doumenge et al. 1995). In these ecosystems, decomposition of root and leaf litter is reduced in comparison with lowland tropical forest (Coûteaux et al. 2002). Thus, tropical mountain forests contribute substantially to carbon sequestration in soils. An important component of ecosystem carbon cycling is soil CO2 efflux from the soil to the atmosphere, which results from the activity of soil microbes and root respiration. Globally CO2 efflux amounts to approximately 80 Pg C year-1. Tropical and subtropical evergreen broadleaved forests contribute the largest parts of approx. 22 Pg C year-1 (Raich et al. 2002). Through human activity, especially burning of fossil fuels and conversion of forests into other land use forms, about 7 Pg C enter the atmosphere additionally per year as carbon dioxide. It is assumed that increasing CO2 in the atmosphere are a main cause for higher temperatures observed (Rustad 2001), but as long as it remains unclear how carbon pools and fluxes react on this rise of the temperatures, it is also remains unclear how the global carbon cycle will be altered by climate change in the long term. The objective of this study was to quantify total carbon and nitrogen contents, microbial biomass and total, heterotrophic and root respiration between 1050 m and 3060 m along an altitudinal gradient in natural forests of the research area. Details of the study sites are given by Moser et al. (Chapter 15 in this volume).

There are only a few studies on soils and their bioelement status in primary forest and forest-derived land use for mountain rainforests (Rhoades et al. 2000); most investigations up to now have focused on lowland tropics. Important changes in physical and chemical soil characteristics and biological cycles follow pasture establishment and can affect soil fertility and the interaction of soils

The isotopic composition of air-borne sulphur was investigated in Saxony, Southeast Germany--a region with formerly very high atmospheric SO(2) concentrations. In addition, data from various authors were compiled for different Saxonian locations, spanning from 1992 to 2004, i.e., a time of decreasing SO(2) concentrations in the atmosphere. There were no obvious temporal changes in the mean delta(34)S value of bulk precipitation. However, the variability of monthly mean delta(34)S values decreased. The mean sulphur isotope composition of sulphate from bulk precipitation after the year 2000 converges in Saxony towards 4-5 per thousand, with similar values for different locations. Mean values of different forms of sulphur show the following enrichment order: delta(34)S of SO(2) < delta(34)S of weathering crusts < or =delta(34)S of sulphate from bulk precipitation < or =delta(34)S of dust. Judging from local differences on sulphate crusts and corresponding isotope values of sources, the delta(34)S value of SO(2) as well as for crusts mainly reflects local point sources. The mean delta(34)S value of bulk precipitation represents more regionally well-mixed SO(2) sources and is therefore an ideal tool for monitoring regional atmospheric change.

At Wurgwitz near Dresden, Saxony, Germany, a quarry was opened recently to retrieve material from the “Wilsdruff-Potschappel Porphyrite”. This Permo-Carboniferous, latitic-andesitic lava flow shows intensive alter-ation features in its upper sections. The material is dissected ...