Bridging the Faraoni and Selli oceanic anoxic events: late Hauterivian to early Aptian dysaerobic to anaerobic phases in the Tethys.

A detailed geochemical analysis was performed on the upper part of the Maiolica Formation in the Breggia (southern Switzerland) and Capriolo sections (northern Italy). The analysed sediments consist of well-bedded, partly siliceous, pelagic carbonate, which lodges numerous thin, dark and organic-rich layers. Stable-isotope, phosphorus, organic-carbon and a suite of redox-sensitive trace-element contents (RSTE: Mo, U, Co, V and As) were measured. The RSTE pattern and Corg:Ptot ratios indicate that most organic-rich layers were deposited under dysaerobic rather than anaerobic conditions and that latter conditions were likely restricted to short intervals in the latest Hauterivian, the early Barremian and the pre-Selli early Aptian. Correlations are both possible with organic-rich intervals in central Italy (the Gorgo a Cerbara section) and the Boreal Lower Saxony Basin, as well as with the facies and drowning pattern in the Helvetic segment of the northern Tethyan carbonate platform. Our data and correlations suggest that the latest Hauterivian witnessed the progressive installation of dysaerobic conditions in the Tethys, which went along with the onset in sediment condensation, phosphogenesis and platform drowning on the northern Tethyan margin, and which culminated in the Faraoni anoxic episode. This episode is followed by further episodes of dysaerobic conditions in the Tethys and the Lower Saxony Basin, which became more frequent and progressively stronger in the late early Barremian. Platform drowning persisted and did not halt before the latest early Barremian. The late Barremian witnessed diminishing frequencies and intensities in dysaerobic conditions, which went along with the progressive installation of the Urgonian carbonate platform. Near the Barremian-Aptian boundary, the increasing density in dysaerobic episodes in the Tethyan and Lower Saxony Basins is paralleled by a change towards heterozoan carbonate production on the northern Tethyan shelf. The following return to more oxygenated conditions is correlated with the second phase of Urgonian platform growth and the period immediately preceding and corresponding to the Selli anoxic episode is characterised by renewed platform drowning and the change to heterozoan carbonate production. Changes towards more humid climate conditions were the likely cause for the repetitive installation of dys- to anaerobic conditions in the Tethyan and Boreal basins and the accompanying changes in the evolution of the carbonate platform towards heterozoan carbonate-producing ecosystems and platform drowning.

Teores de metais na biomassa de Egeria densa, Egeria najas e Ceratophyllum demersum

Este estudo foi realizado com o objetivo de se estimar o conteúdo de elementos metálicos presentes em três macrófitas aquáticas submersas, procurando avaliar a participação destas plantas na remoção destes elementos na água e criar base de dados que permita prever o impacto ambiental do descarte delas em solo ou na própria água. As amostras foram desidratadas, moídas e encaminhadas aos laboratórios para análise e quantificação dos elementos. Para as três espécies, a maior concentração de elementos foi observada durante o verão, ocorrendo declínio nas concentrações durante o inverno, principalmente para os elementos vanádio e chumbo. Não foi detectada presença do elemento mercúrio em nenhuma das amostras.

Geochemical Study of the Itabirite Iron Ores of the Alegria Mine - Quadrilátero Ferrífero, Minas Gerais, Brazil

The iron ores of Alegria mine are composed of itabirites enclosing minor bodies of high-grade ores. The itabirites are classified according to mineralogical composition in five types: martite-rich, goethite-rich, specularite-rich, magnetite-rich and anphibolite-rich ores. The hematites are martite-rich, magnetite-rich, specularite-rich and more rarely, amphibolite-rich. Other classification criteria of the ores are based on the physical properties and the degree of compaction. As such, the itabirites and hematites can be classified as hard, friable and soft types. The mineralogical/textural evolution of the ores is linked to the pressure and temperature conditions that accompanied the tectonic processes in anphibolite facies and the different degrees of subsequent surficial weathering processes. Petrographic and microstructural studies indicate that the magnetite and amphibole bearing itabirites represent the parent rocks that created the other itabirites and that the specularite itabirites and the hard martite types are related to silica dissolution and redeposition in zones of high and low strain. Most of itabirites ores correspond to chert oxide facies banded iron formation, except the goethite and amphibole bearing itabirite that resemble a silicate or oxide-silicate facies with minor carbonate impurities. The great mass and pods of soft martite itabirites are probably shaley oxide facies BIFs with little volcanic contribution. Trace element contents of the Alegria's itabirites show strong dissimilarities with BIFs associated with volcanism (Algoma type), but closely ressemble to the Lake Superior type, with high content in Cr, Co and low V, Ni, Cu and Zn. Although the absolute contents of REE present in the Alegria's itabirites are, in general very low, the pattern when normalised by NASC is similar to the great majority of the Archean and Paleoproterozoic BIFs elsewhere in the world, and characterised by positive Eu anomaly.

Características fenotípicas de 44 progênies de espinheira-santa (Maytenus ilicifolia Mart. ex Reiss) cultivadas no município de Ponta Grossa, PR

Due to the confirmation of its medicinal properties, the demand and the area planted with 'espinheira-santa' have been increasing. However, there are no sources of propagation material with known characteristics. Progenies of Maytenus ilicifolia Martius ex Reiss (espinheira-santa), originating from Southern Brazil have been analyzed, and currently comprise a germplasm inventory for the species. Studies included the assessment of in natura growth features (height and production of biomass canopy) and plant chemistry (lignin, phenols and mineral element contents), and targeted the creation of a data base, characterizing populations/progenies to be used in future selection and breeding programs of the species. Among the features assessed, were considered desirable the ones related to productivity (high foliar mass to branch mass ratio) and also the absence of thorns on the leaves. High total phenol and tannin content were observed in all the progenies assessed and these features is desirable as long the absence of toxic effects and preservation of the therapeutic quality of the plant medicinal elements produced can be proved.

Crustal growth in the 3.4-2.7Ga São José de Campestre Massif, Borborema Province, NE Brazil

The Archean (3.45-2.70Ga) rocks of the São José do Campestre Massif (SJCM) in the Borborema Province (NE Brazil) make up a small area (~6000km2) and are composed of granitoids and metasupracrustal rocks that define a complex magmatic and deformational history. The massif provides the opportunity to study mantle- and crustal-derived magmas generated since the Palaeoarchean. The orthogneisses of the SJCM are composed of: (1) tonalite to granodiorite with diorite enclaves (Bom Jesus gneiss, 3412±8Ma; TDM Nd model ages from 4.1 to 3.5Ga and negative epsilon Nd values); (2) biotite and ferroan-diopside monzogranite (Presidente Juscelino complex, 3356±21Ma and 3251±44Ma; TDM model ages range from 4.1 to 3.4Ga and epsilon Nd values that are slightly positive to negative); (3) hornblende tonalite to granodiorite (Brejinho complex, 3333±77Ma and 3187±8Ma; dominantly positive epsilon Nd values and TDM ages from 3.6 to 3.2Ga); (4) biotite monzogranite (São Pedro do Potengi gneiss, 3120±22Ma; TDM =3.5Ga; negative epsilon Nd value); (5) ferroan-diopside-grossular anorthosite and metagabbro (Senador Elói de Souza complex, 3033±3Ma); and (6) quartz diorite to syenogranite (São José do Campestre complex; 2685±9Ma and 2655±4Ma; negative epsilon Nd values and TDM ages from 3.9 to 3.3Ga). The orthogneisses are subalkaline to faintly alkaline, magnesian to ferroan, M- and I-type granitoids that follow either the K-enrichment or the trondhjemite trends. Each group has a subset with REE characteristics similar to Archean TTG and another that is analogous to Phanerozoic granitoids. They have negative Ta-Nb and Ti anomalies and have trace element contents of granitoids from subduction zones. Geochemical and Nd isotope data suggest that subducted oceanic crust and a depleted and metasomatised mantle wedge both acted as the magma sources. We propose a convergent tectonic model in which hybridisation of the upper mantle occurs through interactions with adakitic or trondhjemitic melts and recycling of earlier crust. The results imply that both the subducted oceanic crust and the mantle wedge played major roles in continent formation throughout successive episodes of arc accretion in Palaeo- and Mesoarchean times. The Archean rocks of the SJCM shares some similarities with the Pilbara, Kaapvaal, West African, and São Francisco cratons. However, the most reliable comparisons with the SJCM are with the neighbouring basement of the Nigeria and Cameroon shields. © 2012 Elsevier B.V.

Aplicação via fertirrigação de soluções com diferentes condutividades elétricas para produção de gérbera (Gerbera jamesonii L.) sob ambiente protegido

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Whole-rock geochemistry and Sr-Nd isotopic composition of the pre-rift sequence of the Camamu Basin, northeastern Brazil

Whole-rock geochemistry, combined with Sr-Nd isotopic composition of pelitic sedimentary rocks, have been considered to be useful parameters to estimate not only their provenance but also to make inferences about their depositional environment as well as the weathering processes they have been through. The basal sedimentary units of the basins of the northeastern Brazilian continental margin, particularly those of the pre-rift sequence, have been subject of interest of studies based on chemical and isotopic data, since they lack fossil content to establish their age and, therefore, stratigraphic correlations are difficult. The major and trace element contents as well as Sr-Nd isotopic compositions of whole-rock shale samples from five outcrops attributed to the pre-rift supersequence of the Camamu Basin were analyzed with the purpose of characterizing and obtaining further information that would allow a better correlation between the sites studied. The geochemical data suggest that the rocks exposed in the studied outcrops are part of the same sedimentary unit and that they might be correlated to the Capianga Member of the Alianca Formation of the Reconcavo Basin, exposed to the north of the Camamu Basin. The chemical index of alteration (CIA) suggests conditions associated with a humid tropical/subtropical climate at the time of deposition. Nd isotopic compositions indicate provenance from the Paleoproterozoic rocks of the Sao Francisco craton. The results presented here, therefore, show that the combined use of chemical and isotopic analyses may be of great interest to characterize and correlate lithologically homogeneous clastic sedimentary sequences. (C) 2012 Elsevier Ltd. All rights reserved.

Caratteristiche merceologiche, nutrizionali, sensoriali e di freschezza di Nasello (Merluccius merluccius), Lanzardo (Scomber japonicus) e Suro (Trachurus trachurus)

Three finfish species frequently caught in the waters of the Gulf of Manfredonia (Apulia, Italy) were studied in order to know how the flesh composition (proximate, fatty acid, macro- and micro- element contents) could be affected by the season effect. The species we examined were European hake (Merluccius merluccius), chub mackerel (Scomber japonicus) and horse mackerel (Trachurus trachurus), which were analysed at the raw state in three catch season and after cooking in two catch season. More precisely, European hake and chub mackerel caught during winter, summer and fall were analysed at the raw state. The composition of the flesh of grilled European hake and chub mackerel was study on fish caught in winter and fall. Horse mackerel of summer and winter catches were analysed both at the raw and grilled state. Furthermore, an overall sensory profile was outlined for each species in two catch season and the relevant spider web diagrams compared. On the whole, two hundred and eighty fish were analysed during this research project in order to obtain a nutritional profile of the three species. One hundred and fifty was the overall number of specimens used to create complete sensory profiles and compare them among the species. The three finfish species proved to be quite interesting for their proximate, fatty acids, macro- and micro-element contents. Nutritional and sensory changes occurred as seasons elapsed for chub and horse mackerel only. A high variability of flesh composition seemed to characterise these two species. European hake confirmed its mild sensory profile and good nutritional characteristics, which were not affected by any season effect.

Petrographie und Geochemie des Eckfelder Maares und von Hillscheid und die Einbindung in den Hocheifelvulkanismus

Tertiäre Vulkanite aus dem Eckfelder Maar, dem Hillscheider Diatrem und dem Hillscheid Basalt (Schlot) wurden petrologisch und geochemisch untersucht. Bis auf tonige Klasten aus dem Bohrkern des Eckfelder Maares handelt es sich bei allen weiteren Proben um undifferenzierte basische Vulkanite. Die tonigen Klasten aus dem Bohrkern müssen der ehemaligen Landoberfläche vor der Eruption des Eckfelder Maares zugerechnet werden, in dessen Krater sie während der Eruption hineingefallen sind. Bis auf die Proben des Hillscheid Basaltes sind die Proben alteriert. Die Alteration zeigt sich an der Bildung von Zeolithen und Calcitmineralisationen, die primär und sekundär gebildete Hohlräume aufgefüllt haben oder an einer vertonten Grundmasse der Proben, die daneben Mineraleinschlüsse (Spinell) und kantige Fremdgesteinsbruchstücke enthalten können. Bei den Proben mit vertonter Grundmasse handelt es sich um Palagonite, Umwandlungsprodukte aus Sideromelan (basaltischem Glas). Geochemische Analysen an Grundmassepräparaten der alterierten bis vertonten Proben zeigen, dass außer den immobilen Elementen Ti, Nb, Zr, Y alle weiteren Elemente teilweise bis vollständig abgereichert worden sind. Eine Ausnahme bildet Barium (Ba), welches z.T. in beträchtlichen Mengen in Zeolithen (Harmotom) angereichert wurde. Bei den Proben aus dem Eckfelder Maar kann die Alteration bis Vertonung der Proben alleine mit der Palagonitisierung und Verwitterung erklärt werden. Es gibt keine Hinweise auf Materialzufuhr und damit für sich anschließende hydrothermale Prozesse. Die Proben des Hillscheider Diatrem sind wesentlich geringer alteriert (glasige Grundmasse). Neuste Erkenntnisse aus einer Bohrung im Sommer 1999 im vermuteten Zentrum des Hillscheider Diatrems beschränken das Diatrem maximal auf einen kleineren Bereich im Nordosten der bisherigen Lokation. Bei der Bohrung stieß man nach 20 Meter auf Anstehendes. Im Hangschutt darüber fand man Blöcke des Hillscheid Basaltes. Eine geringere Größe der Lokation zusammen mit der geringen Alteration könnten auf deren Entstehung mit einer initialen Maarphase gefolgt von Schlackentätigkeit hinweisen. Die Schlacken könnten die ersten Ablagerungen vor Verwitterung geschützt haben. Allerdings gibt es keine Funde die eine Schlackentätigkeit belegen. Beim sogenannten 'Hillscheider Diatrem' könnte es sich aber auch um Hangschutt aus der Randbreccie des Hillscheider Basaltes handeln. Zusammen mit Bruchstücken aus dem Schlot des Hillscheid Basaltes wären die Palagonite des sogenannten 'Hillscheider Diatrem' erst in jüngster Zeit im Bereich einer Uferböschung zur Ablagerung gekommen. Dies würde allerdings das sogenannte 'Hillscheider Diatrem' in seiner Existenz in Frage stellen. Vergleiche der Proben des Hillscheid Basaltes mit basischen Hocheifelvulkaniten deuten auf kogenetische Beziehung aller Proben untereinander und ordnen die Proben des Hillscheid Basaltes geochemisch dem Hocheifelvulkanismus zu. REE- und weitere Spurenelementgehalte und auch deren Elementverhältnisse weisen für alle tertiären Eifelvulkanite gemeinsam auf Mantelschmelzen aus dem Bereich eines Granatperidotits mit niedrigen Aufschmelzgraden um ein Prozent hin. Vergleich der Elementverhältnisse hochinkompatibler Elemente im Bezug auf die Bildung mafischer Schmelzen mit primitivem Mantel deuten darauf hin, dass der Mantel im Bereich der Hocheifel verarmt ist an K, Rb, Sr und angereichert an Ba und eventuell an Nb. Ursachen für diese von typisch primären Mantelzusammensetzung abweichenden Verhältnisse könnten durch Mischungen von Mantelschmelzen mit lithosphärischem Mantel (K-Anomalie) und durch Anreicherungen mit fluiden Phasen (Ba-Anomalie) oder auch Schmelzen aus einem tieferliegenden Plume (Kelberger Hoch) verursacht worden sein. Englischer Zusammenfassung:

Nature and origin of ultramafic lamprophyres and carbonatites from the borders of the Labrador Sea

Die Ränder des Labrador Meeres wurden während des späten Neoproterozoikums intensiv von karbonatreichen silikatischen Schmelzen durchsetzt. Diese Schmelzen bildeted sich bei Drucken zwischen ca. 4-6 GPa (ca. 120-180 km Tiefe) an der Basis der kontinentalen Mantel-Lithosphäre. Diese Magmengenerierung steht in zeitlichem und räumlichem Zusammenhang mit kontinentalen Extensionsprozessen, welche zu beiden Seiten des sich öffnenden Iapetus-Ozeans auftraten.

GSR deposition along the bullet path in contact shots to composite models

In contact shots, all the materials emerging from the muzzle (combustion gases, soot, powder grains, and metals from the primer) will be driven into the depth of the entrance wound and the following sections of the bullet track. The so-called "pocket" ("powder cavity") under the skin containing soot and gunpowder particles is regarded as a significant indicator of a contact entrance wound since one would expect that the quantity of GSR deposited along the bullet's path rapidly declines towards the exit hole. Nevertheless, experience has shown that soot, powder particles, and carboxyhemoglobin may be found not only in the initial part of the wound channel, but also far away from the entrance and even at the exit. In order to investigate the propagation of GSRs under standardized conditions, contact test shots were fired against composite models of pig skin and 25-cm-long gelatin blocks using 9-mm Luger pistol cartridges with two different primers (Sinoxid® and Sintox®). Subsequently, 1-cm-thick layers of the gelatin blocks were examined as to their primer element contents (lead, barium, and antimony as discharge residues of Sinoxid® as well as zinc and titanium from Sintox®) by means of X-ray fluorescence spectroscopy. As expected, the highest element concentrations were found in the initial parts of the bullet tracks, but also the distal sections contained detectable amounts of the respective primer elements. The same was true for amorphous soot and unburned/partly burned powder particles, which could be demonstrated even at the exit site. With the help of a high-speed motion camera it was shown that for a short time the temporary cavitation extends from the entrance to the exit thus facilitating the unlimited spread of discharge residues along the whole bullet path.

Jatropha mahafalensis oil from Madagascar: properties and suitability as liquid biofuel

Access to affordable and renewable sources of energy is crucial to reducing poverty and enhancing rural development in countries of the global South. Straight vegetable oil was recently identified as a possible alternative to conventional biomass for rural energy supply. In this context, the Jatropha curcas Linn. species has been extensively investigated with regard to its potential as a biofuel feedstock. In contrast, only little is known about Jatropha mahafalensis Jum. & H. Perrier, which is an indigenous and endemic representative of the Jatropha genus in Madagascar. This paper explores the potential and suitability of J. mahafalensis as a biofuel feedstock. Seed samples were collected in the area of Soalara in south-western Madagascar in February and September 2011. Two agro-ecological zones (coastal area and calcareous plateau) and two plant age groups (below and above 10 years) were considered. These four sample groups were analyzed with regard to oil properties, element contents, and fatty acid profiles. Measured values differed greatly between the two harvests, probably owing to different climatic or storage conditions. No direct relation between age of trees or location and oil quality could be established. The analyses indicate that J. mahafalensis oil can be used in oil lamps, cooking stoves and stationary combustion engines for electrification or for biodiesel production. However, modifications in storage and extraction methods, as well as further processing steps are necessary to enable its utilization as a straight vegetable oil and feedstock for biodiesel production. If these technical requirements can be met, and if it turns out that J. mahafalensis oil is economically competitive in comparison with firewood, charcoal, paraffin and petroleum, it can be considered as a promising feedstock for rural energy supply.

Geochemistry and radionuclide content of sediment and water samples obtained from the Ob and Irtysh river, Russia

This paper reports the results of the investigations of 2006-2007 on the distribution and migration forms of artificial radionuclides and chemical elements in the Ob-Irtysh water system. Three regions were studied. One of them is a local segment of the Ob River upstream from the confluence with the Irtysh River; its investigation allowed us to estimate the general radioecological state of the aquatic environment affected by the activity of the Tomsk 7 plant. The second region is a local segment of the Irtysh River upstream from its confluence with the Ob River, where the influence of emissions from the NPO Mayak could be estimated. The third region is the water area of the Ob River after its confluence with the Irtysh River. It characterizes the real level of radioactive and chemical contamination of the middle reaches of the Ob River. In order to explain horizontal variations in the distribution of radionuclides in the upper layer of bottom sediments collected at various sites, the results of sorption-kinetic experiments with radioactive tracers in the precipitate-solution system were used. The investigation of the migration forms of trace elements and radionuclides occurring in river water was based on the method of tangential-flow membrane filtration. Chemical element contents were determined in 400-ml water samples. A set of Millipore polysulfone membranes with pore sizes of 8, 1.2, 0.45, 0.1, and 0.025 µm was employed. Taking into account the ultralow specific concentrations of radionuclides in the water, they were analyzed in 300-500 litre samples using Millipore polysulfone membranes with pore sizes of 0.45 µm and 15 kDa. This allowed us to estimate the percentages of cesium-137 and plutonium-239, 240 in the suspended particulate fraction, colloids, and dissolved species.

Chemical composition of bottom sediments from the northern part of the Deryugin Trough, Sea of Okhotsk

Distribution trace element contents in the upper (up to 5 m) Holocene-Upper Pleistocene sediment layer along the northern and southern sublatitudinal profiles in the northern part of the Deryugin Trough is discussed. Mathematical processing of chemical analysis data has been made. On the basis of the cluster analysis 16 elements have been combined into 5 geochemical groups. Two of them (1 - Ag-Mo group and 2 - Mn-Ba-Ni-Sr group) were considered in detail. Analysis of Ag and Mo distributions in the sediments and findings of molybdenite permitted to conclude that enrichment of the sediments by these elements resulted from edaphic washing of magmatic rocks containing Ag-Mo mineralization and probably located on the northwestern slope of the Deryugin trough. The second geochemical group is most likely connected with hydrothermal barite mineralization found in the northeastern part of the Deryugin trough. Considering Mn distribution in bottom sediment cores supply of Mn was pulsating. This allows concluding that during Holocene - Late Pleistocene three cycles of hydrothermal activity occurred in the Deryugin Trough, and the most intensive one was in Holocene.

Geochemistry and isotopic ratios of basalts obtained during R/V Akademik Nikolaj Strakhov cruise ANS25

Based on the investigation of samples recovered during Cruise 25 of the R/V ''Akademik Nikolai Strakhov'', the character of magmatism was determined in the flank parts of the rift zone at the 74°05'N and 73°50'N region, where the direction of the rift valley changes from the north-northwest in the Knipovich Ridge to the northeast-trending structures of the Mohns Ridge. It was shown that the tholeiitic magmas of this region shows all the geochemical characteristics of TOR-2, which is typical of the Mohns Ridge and most oceanic rift zones worldwide, and differ from the basalts of the Knipovich Ridge, which are assigned to a shallower type of tholeiitic magmatism (Na-TOR). The persistent depletion of the magmas in terms of lithophile element contents and radiogenic isotope ratios of Sr, Nd, and Pb reflects the conditions of their formation during the ascent of the depleted oceanic mantle, which has occurred without significant complications since the early stages of the formation of the Mohns Ridge.