Search Results

You are looking at 1 - 10 of 55 items for :

  • "concentration" x
  • Earth and Environmental Sciences x
  • All content x
Clear All

2008 Shell layer variation in trace element concentration for the freshwater bivalve Elliptio complanata Geo-Marine Letters 28 369 381

Restricted access

One of the most important ores for REE mineralization are iron oxide–apatite (IOA) deposits. The Posht-e-Badam Block (PBB) is a part of the Central Iranian geostructural zone which is the host of most important Fe deposits of Iran. Exploration studies of the IOA deposits within the PBB (e.g. Esphordi, Gazestan, Zarigan, Lak-e-Siah, Sechahoun, Chahgaz, Mishdovan, Cheshmeh Firouzi and Shekarab) demonstrate that these deposits contain high contents of REE. Concentrations of ΣREE in the most important IOA deposits of the PBB include the following: the Esphordi deposit varies between 1.2 and 1.88%, the Gazestan deposit between 0.17 and 1.57%, the Zarigan deposit between 0.5 and 1.2% and the Lak-e-Siah deposit varies between 0.45 and 1.36%. Concentrations of ΣREE within the apatite crystals present within the IOA ores in the Esphordi, Lak-e-Siah and Homeijan deposits have ranges between 1.9–2.54%, 1.9–2.16% and of 2.55%, respectively. These elements are mainly concentrated in apatite crystals, but other minerals such as monazite, xenotime, bastnasite, urtite, alanite, thorite, parisite–synchysite and britholite have been recognized as hosts of REEs, as small inclusions within the apatite crystals, and in subsequent carbonate, hematite–carbonate and quartz veins and veinlets. Given the extent of this block and the presence of several IOA deposits within this block, and also the high grades of REEs within these deposits, one can reasonably state that it is obvious that there are significant resources of REEs in this part of Iran.

Open access

This article evaluates the known rare earth elements (REE), Ti and Li occurrences and exploration potential in Finland, based on existing data combined with new geochemistry and mineralogy, heavy mineral studies, geophysical measurements, geologic mapping and recent drilling of new targets.

The potential rock types for REE include carbonatite (Sokli, Korsnäs), alkaline rocks (Otanmäki, Lamujärvi, and Iivaara), rapakivi granite and pegmatite (Kovela), and kaolin-bearing weathering crusts in eastern and northern Finland. The highest REE concentrations occur in late magmatic carbonatite veins in the fenite area of the Sokli carbonatite complex. Detailed mineralogical investigations have revealed three distinct types of REE mineralization as phosphates, carbonates and silicates in the studied areas. Mineralogical and mineral chemical evidence demonstrates that hydrothermal processes are responsible for the REE mineralization in the studied rocks and confirms that such processes are predominant in the formation of REE minerals in carbonatite, calc-silicate rocks and albitite. Titanium occurs as ilmenite in hard rock deposits in Paleoproterozoic subalkaline mafic intrusions. The Otanmäki ilmenite was mined together with vanadium-rich magnetite from 1953 to 1985 from a small gabbro—anorthosite complex, which still contains potential for Ti resources. Other major ilmenite deposits are within the Koivusaarenneva ilmenite gabbro intrusion and Kauhajärvi apatite—ilmenite—magnetite gabbro complex. Possible Ti resources are included in Ti-magnetite gabbro of the large layered mafic intrusions in northern Finland, such as at the former Mustavaara vanadium mine. For several years, Rare Element (RE)-pegmatite of the Kaustinen and Somero—Tammela areas has been the objective of Li exploration by the Geological Survey of Finland (GTK). At Kaustinen, Li-pegmatite occurs as subparallel dyke swarms in an area of 500 km2 within Paleoproterozoic mica schists and metavolcanic rocks. Li pegmatite contains more than 10% spodumene as megacrysts (1–10 cm), albite, quartz, K-feldspar, muscovite and accessory minerals such as columbite-group minerals, apatite, tourmaline, beryl, Fe-oxide minerals and garnet. The Kaustinen spodumene pegmatite and Somero—Tammela petalite—spodumene pegmatite contain potential Li resources for the battery industry in EU countries.

Open access

2002 Ambient concentrations and dry deposition fluxes of trace elements in Izmir, Turkey Atmospheric Environment 36 5841 5851

Restricted access

Evidence for bias in C and N concentrations and delta C-13 composition of terrestrial and aquatic organic materials due to pre-analysis acid preparation methods Chemical Geology 282 3

Restricted access
Central European Geology
Authors: Zsuzsanna Szabó, Nóra Edit Gál, Éva Kun, Teodóra Szőcs, and György Falus

, whereas dolomite, Ca-montmorillonite, and kaolinite precipitate. At the reaction front, illite precipitation is predicted. These processes change the solution composition (Fig.  6 , bottom left). K, Mg, Ca, and Si concentrations increase, among which K

Open access

R. Vincent 2010 Concentration distribution and bioaccessibility of trace elements in nano and fine urban airborne particulate matter: Influence of particle size Water, Air

Restricted access
Central European Geology
Authors: Vladimir Naumov, Vladimir Kovalenker, Gheorghe Damian, Sergei Abramov, Maria Tolstykh, Vsevolod Prokofiev, Floarea Damian, and Ioan Seghedi

.N. Kononkova 1992: Magmatic water under a pressure of 15–17 kbar and its concentration in melt: the first data on inclusions in plagioclases in andesites. — Dokl. Russ. Acad. Nauk, 324, 3, pp. 654–658. (In Russian

Restricted access
Central European Geology
Authors: Ubul Fügedi, László Kuti, Daniella Tolmács, Ildikó Szentpétery, Barbara Kerék, Tímea Dobos, András Sebők, and Rita Szeiler

. Horváth, L. Ódor 2007: Geokémiai háttérértékek Magyarország hegyvidéki területein (Geochemical background concentrations in the mountainous areas of Hungary). - Földtani Közlöny, 137(1), pp. 63–74. Ódor L

Restricted access

concentrations were either measured on-site or in the laboratory, according to Hungarian and international standards. The availability of WQ data restricted the number of creeks: only 101 of the total of 638 “small” (LMQ < 1 m 3 s −1 ) rivers were involved in

Open access