1,721,111 research outputs found
Metodo per trattare sostanze organiche e per realizzare un fertilizzante
No full textUn metodo per trattare sostanze organiche fluide di scarto contenenti azoto ammoniacale, in particolare sostanze derivanti da rifiuti, scarti, decomposizioni, in particolare reflui zootecnici liquidi e/o digestati derivanti da processi di degradazione organica con microorganismi, e per realizzare un materiale fertilizzante a rilascio lento e controllato di azoto ammoniacale, comprende le fasi di:
- predisporre zeolititi, ossia rocce contenenti zeolite in concentrazione maggiore del 50%;
- addizionare a dette zeolititi dette sostanze organiche fluide di scarto e miscelare;
- agitare dette zeolititi e dette sostanze organiche fluide di scarto per un tempo di agitazione;
- lasciare sedimentare dette zeolititi con dette sostanze organiche fluide di scarto per un tempo di sedimentazione in modo tale che dette zeolititi assorbano e sottraggano per scambio cationico azoto ammoniacale da dette sostanze organiche fluide di scarto;
dette zeolititi arricchite in azoto ammoniacale costituendo un materiale fertilizzante, che, quando introdotto in un terreno agricolo, è in grado di rilasciare detto azoto ammoniacale a radici di piante solo quando queste ultime rilasciano acidi umici
Slab melt and intraplate metasomatism in Kapfenstein mantle xenoliths (Styrian Basin, Austria)
No full textAnhydrous and amphibole-bearing mantle peridotite xenoliths from Kapfenstein (Styrian Basin) have been studied with the aim of understanding both the processes responsible for amphibole formation and the nature of metasomatizing agents which affected this portion of lithosphere. This area of the Pannonian Basin underwent a subduction event which was followed after about 15 Ma, by alkaline intraplate magmatism. Primary clinopyroxene (cpx1) in four-phase lherzolite xenoliths is characterized by LREE-depleted to slightly LREE-enriched patterns. LREE-depleted cpx1 have low Th and U contents and Zr (and Hf) anomalies varying from slightly negative to positive. LREE-enriched cpx have high Th and U contents and remarkable positive anomalies of Zr and Hf. Primary clinopyroxenes in amphibole-bearing lherzolites present a comparable compositional variation from LREE (and Th, U, Zr, Hf)-depleted type to LREE (and Th, U, Zr, Hf)-enriched type. LREE-depleted cpx1, with strong negative Zr and Ti anomalies, are also recognized in the peridotite matrix of a composite sample cut by a large amphibole vein. Textural and geochemical evidence indicates that amphibole disseminated within the matrix grew at the expense of primary spinel and clinopyroxene, mimicking the trace element patterns of the latter. As a consequence, the geochemical features of amphibole vary in relation to those of clinopyroxene, from enriched to depleted. On the other hand, the composition of vein amphibole in the composite xenolith compares well with amphibole megacrysts and microphenocrysts, suggesting that it represents a fractionation product of alkaline melt that passed through the lithosphere. Two kinds of metasomatism, superimposed on a slightly depleted lithospheric mantle, were identified. A slab-derived melt (proto-adakite?) metasomatic agent was responsible for the first enrichment in Th, U, Zr and Hf observed in clinopyroxene, whereas an alkaline within-plate metasomatic agent caused the formation of the Nb (and Ta)- rich disseminated amphibole. The final process was the alkaline magmatism, which was responsible for the formation of the large amphibole vein and megacrysts. It is proposed that the Nb-poor and Nb-rich amphiboles record the transition between the suprasubduction slab melt-related and the intraplate alkaline metasomatism.
These geochemical features are consistent with a lithospheric portion enriched in slab melt components which was subsequently metasomatized by alkaline melt. Alternatively an asthenospheric uprising could have scavenged a previously slab melt-enriched region of the lithosphere. (C) 2006 Elsevier B.V. All rights reserved
Slab melt metasomatism recorded in ultramafic xenoliths from Cerro del Fraile (Argentina)
No full textThe use of particle density in sedimentary provenance studies: the superficial sediment of Po Plain (Italy) case study
No full textIn recent years, several approaches for the identification
of the provenance of the sediments have been developed. In
particular, geochemical, petrographic and mineralogical analyses
were applied to the sediments of the Po Plain in order to discriminate
the alluvial sediments of the Po River from those coming
from Apennine rivers. In this work, we propose an innovative
technique based on the measurement of density for the study of
the Po Plain alluvial sediments. This study is based on the determination
of major and trace elements, particle density and mineralogical
composition of 53 superficial sediments. All the data were
processed using multivariate statistics. The comparison between
density, geochemistry, and granulometry of the Po River and Reno
River (the most important Apennine river) samples shows how the
densities strictly depend on the chemical-mineralogical composition
and grain size of the sediments and, consequently, on the type of
hydrographic basin of their respective river. On this basis it can be
discriminated the provenance of two different types of alluvial sediments
with sufficient precision, determining the density of the
unconsolidated alluvial material
Petrological features of mantle xenoliths from South Auckland Volcanic Provinces, North Island, New Zealand
No full textTextural and chemical relationships between amphibole and peridotitic phases in Ichinomegata mantle xenoliths.
No full textMineralogical quantitative analyses and petrological study of mantle xenoliths from Harrow Peaks (Northern Victoria Land, Antarctica).
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