scholarly journals Incipient Wolframite Deposition at Panasqueira (Portugal): W Rutile and Tourmaline Compositions as Proxies for the Early Fluid Composition

2020 ◽  
Author(s):  
Eleonora Carocci ◽  
Christian Marignac ◽  
Michel Cathelineau ◽  
Laurent Truche ◽  
Marc Poujol ◽  
...  
Keyword(s):  
Element Concentration ◽  
Trace Element Concentration ◽  
Fluid Mixing ◽  
Fluid Composition ◽  
Rock Interaction ◽  
Early Introduction ◽  
Icp Ms ◽  
End Members ◽  
Early Fluid ◽  
Micrometer Scale

Abstract The main event responsible for the deposition of tungsten at Panasqueira was closely associated with strong tourmalinization of the wall rocks. Tourmaline is coeval with a W-rich rutile (up to 8–10 wt % W), and both minerals record an early introduction of W in the system, just before the main W deposition. Uranium-Pb dating of the rutile by LA-ICP-MS yielded an age of 305.2 ± 5.7 Ma, which is 6 to 10 m.y. older than the K-Ar age of 296.3 ± 1.2 Ma obtained on muscovite, which was therefore not coeval with wolframite. Major and trace element concentration variations in tourmaline record fluid mixing between two end members, both considered to be of metamorphic derivation on the basis of rare earth element profiles. We report evidence for a fluid rich in Co, Cu, Pb, Sc, Sr, V, Cr, Nb, Ta, and Sn interpreted to be of local origin—e.g., well equilibrated with the host formations—and a fluid rich in Li, F, Fe, Mn, and W inferred to be of deep origin and related to biotite dehydration. The second fluid carried the metals (in particular Fe and Mn) that were necessary for wolframite deposition and that were not necessarily inherited from the wall rocks through fluid-rock interaction. Micrometer-scale variations in tourmaline and rutile crystal chemistry are indicative of pulsatory fluid input during tourmalinization.

Terrigenous debris and mussel pollution — a differentiation based on trace element concentration by means of multivariate analysis

1997 ◽  
Vol 344 (3) ◽  
pp. 251-259 ◽  
Author(s):  
L. Favretto ◽  
B. Campisi ◽  
E. Reisenhofer ◽  
G. Adami
Keyword(s):  
Multivariate Analysis ◽  
Trace Element ◽  
Element Concentration ◽  
Trace Element Concentration

scholarly journals Metal source and fluid–rock interaction in the Archean BIF-hosted Lamego gold mineralization: Microthermometric and LA-ICP-MS analyses of fluid inclusions in quartz veins, Rio das Velhas greenstone belt, Brazil

2016 ◽  
Vol 72 ◽  
pp. 510-531 ◽  
Author(s):  
Milton J. Morales ◽  
Rosaline C. Figueiredo e Silva ◽  
Lydia M. Lobato ◽  
Sylvio D. Gomes ◽  
Caio C.C.O. Gomes ◽  
...  
Keyword(s):  
Fluid Inclusions ◽  
Greenstone Belt ◽  
Gold Mineralization ◽  
Rock Interaction ◽  
Metal Source ◽  
Quartz Veins ◽  
Icp Ms

scholarly journals Dynamics of Trace Element Concentration During Development and Excitotoxic Cell Death in the Cerebellum ofLurcherMutant Mice

2009 ◽  
Vol 19 (4) ◽  
pp. 586-595 ◽  
Author(s):  
Jörg Bäurle ◽  
Jan Kučera ◽  
Sabine Frischmuth ◽  
Manfred Lambertz ◽  
Karel Kranda
Keyword(s):  
Cell Death ◽  
Trace Element ◽  
Element Concentration ◽  
Trace Element Concentration ◽  
Excitotoxic Cell Death

Brain Trace Element Concentration of Rats Treated with the Plant Alkaloid, Vincamine

2009 ◽  
Vol 136 (3) ◽  
pp. 314-319 ◽  
Author(s):  
Abdel-Hasseb A. Fayed
Keyword(s):  
Trace Element ◽  
Element Concentration ◽  
Trace Element Concentration

Oxygen, hydrogen, and strontium isotope constraints on the origin of granites

1988 ◽  
Vol 79 (2-3) ◽  
pp. 317-338 ◽  
Author(s):  
Hugh P. Taylor
Keyword(s):  
Large Scale ◽  
Wide Spectrum ◽  
Volcanic Field ◽  
Parent Material ◽  
Rock Interaction ◽  
Metasedimentary Rocks ◽  
Clear Cut ◽  
End Members ◽  
Type 3

ABSTRACTOxygen isotope data are very useful in determining the source rocks of granitic magmas, particularly when used in combination with Sr, Pb, and Nd isotope studies. For example, unusually high δ18O values in magmas (δ18O> +8) require the involvement of some precursor parent material that at some time in the past resided on or near the Earth's surface, either as sedimentary rocks or as weathered or hydrothermally altered rocks. The isotopic systematics which are preserved in the Mesozoic and Cenozoic batholiths of western North America can be explained by grand-scale mixing of three broadly defined end-members: (1) oceanic island-arc magmas derived from a “depleted” (MORB-type?) source in the upper mantle (δ18O c. +6 and 87Sr/86Sr c. 0·703); (2) a high-18O (c. +13 to +17) source with a very uniform 87Sr/86Sr (c. 0·708 to 0·712), derived mainly from eugeosynclinal volcanogenic sediments and (or) hydrothermally altered basalts; and (3) a much more heterogeneous source (87Sr/86Sr c. 0·706 to 0·750, or higher) with a high δ18O (c. +9 to +15) where derived from supracrustal metasedimentary rocks and a much lower δ18O (c. +7 to +9) where derived from the lower continental crust of the craton. These end-members were successively dominant from W to E, respectively, within three elongate N–S geographic zones that can be mapped from Mexico all the way N to Idaho.18O/16O studies (together with D/H analyses) can, however, play a more important and certainly a unique role in determining the origins of the aqueous fluids involved in the formation of granitic and rhyolitic magmas. Fluid-rock interaction effects are most clear-cut when low-18O, low-D meteoric waters are involved in the isotopic exchange and melting processes, but the effects of other waters such as seawater (with a relatively high δD c. 0) can also be recognised. Because of these hydrothermal processes, rocks that ultimately undergo partial melting may exhibit isotopic signatures considerably different from those that they started with. We discuss three broad classes of potential source materials of such “hydrothermal-anatectic” granitic magmas, based mainly on water/rock (w/r), temperature (T), and the length of time (t) that fluid-rock interaction proceeds: (Type 1) epizonal systems with a wide variation in whole-rock δ18O and extreme 18O/16O disequilibrium among coexisting minerals (e.g. quartz and feldspar); (Type 2) deeper-seated and (or) longer-lived systems, also with a wide spectrum of whole-rock δ18O, but with equilibrated 18O/16O ratios among coexisting minerals; (Type 3) thoroughly homogenised and equilibrated systems with relatively uniform δ18O in all lithologies. Low-18O magmas formed by melting of rocks altered in a Type 2 or a Type 3 meteoric-hydrothermal system are the only kinds of “hydrothermal-anatectic” granitic magmas that are readily recognisable in the geological record. Analogous effects produced by other kinds of aqueous fluids may, however, be quite common, particularly in areas of extensional tectonics and large-scale rifting. The greatly enhanced permeabilities in such fractured terranes make possible the deep convective circulation of ground waters and sedimentary pore fluids. The nature and origin of low-18O magmas in the Yellowstone volcanic field and the Seychelles Islands are briefly reviewed in light of these concepts, as is the development of high-D, peraluminous magmas in the Hercynian of the Pyrenees.

Trace Element Concentration of commercially Available Drinking Water in Makkah and Jeddah

2004 ◽  
Vol 15 (1) ◽  
pp. 149-154
Author(s):  
Z. TAYYEB ◽  
S. FARID ◽  
K. OTAIBI
Keyword(s):  
Drinking Water ◽  
Trace Element ◽  
Element Concentration ◽  
Trace Element Concentration

scholarly journals HFSE‐REE Transfer Mechanisms During Metasomatism of a Late Miocene Peraluminous Granite Intruding a Carbonate Host (Campiglia Marittima, Tuscany)

Minerals ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 682
Author(s):  
Paoli ◽  
Dini ◽  
Petrelli ◽  
Rocchi
Keyword(s):  
External Source ◽  
Magmatic Fluid ◽  
Chemical Components ◽  
Fluid Composition ◽  
Peraluminous Granite ◽  
Rock Interaction ◽  
Complete Replacement ◽  
Element Mobilization ◽  
Geochemical Models ◽  
Metasomatic Event

The different generations of calc‐silicate assemblages formed during sequential metasomatic events make the Campiglia Marittima magmatic–hydrothermal system a prominent case study to investigate the mobility of rare earth element (REE) and other trace elements. These mineralogical assemblages also provide information about the nature and source of metasomatizing fluids. Petrographic and geochemical investigations of granite, endoskarn, and exoskarn bodies provide evidence for the contribution of metasomatizing fluids from an external source. The granitic pluton underwent intense metasomatism during post‐magmatic fluid–rock interaction processes. The system was initially affected by a metasomatic event characterized by circulation of K‐rich and Ca(‐Mg)‐rich fluids. A potassic metasomatic event led to the complete replacement of magmatic biotite, plagioclase, and ilmenite, promoting major element mobilization and crystallization of K‐feldspar, phlogopite, chlorite, titanite, and rutile. The process resulted in significant gain of K, Rb, Ba, and Sr, accompanied by loss of Fe and Na, with metals such as Cu, Zn, Sn, W, and Tl showing significant mobility. Concurrently, the increasing fluid acidity, due to interaction with Ca‐rich fluids, resulted in a diffuse Ca‐metasomatism. During this stage, a wide variety of calc‐silicates formed (diopside, titanite, vesuvianite, garnet, and allanite), throughout the granite body, along granite joints, and at the carbonate–granite contact. In the following stage, Ca‐F‐rich fluids triggered the acidic metasomatism of accessory minerals and the mobilization of high-field-strength elements (HFSE) and REE. This stage is characterized by the exchange of major elements (Ti, Ca, Fe, Al) with HFSE and REE in the forming metasomatic minerals (i.e., titanite, vesuvianite) and the crystallization of HFSE‐REE minerals. Moreover, the observed textural disequilibrium of newly formed minerals (pseudomorphs, patchy zoning, dissolution/reprecipitation textures) suggests the evolution of metasomatizing fluids towards more acidic conditions at lower temperatures. In summary, the selective mobilization of chemical components was related to a shift in fluid composition, pH, and temperature. This study emphasizes the importance of relating field studies and petrographic observations to detailed mineral compositions, leading to the construction of litho‐geochemical models for element mobilization in crustal magmatic‐hydrothermal settings.

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