Cathodoluminescent Textures and Trace Elements in Hydrothermal Quartz

2012 ◽  
pp. 307-329 ◽  
Author(s):  
Brian Rusk
Keyword(s):  
Trace Elements ◽  
Hydrothermal Quartz

scholarly journals Multi-Stage Evolution of Gold-Bearing Hydrothermal Quartz Veins at the Mokrsko Gold Deposit (Czech Republic) Based on Cathodoluminescence, Spectroscopic, and Trace Elements Analyses

Minerals ◽  
2018 ◽  
Vol 8 (8) ◽  
pp. 335 ◽  
Author(s):  
Vojtěch Wertich ◽  
Jaromír Leichmann ◽  
Marek Dosbaba ◽  
Jens Götze
Keyword(s):  
Trace Elements ◽  
Gold Deposit ◽  
Tectonic Setting ◽  
Emission Spectra ◽  
Titanium Concentration ◽  
Quartz Veins ◽  
Hydrothermal Quartz ◽  
Multi Stage ◽  
Regional Tectonic ◽  
Intrusive Suite

We performed a detailed analysis of hydrothermal quartz at the Mokrsko gold deposit (Čelina, Mokrsko-East, and Mokrsko-West deposits). Twenty-one samples were studied by scanning electron microscopy cathodoluminescence (CL) imagining, CL emission spectra and trace elements were measured on six selected samples. Four quartz growth generations Q1 to Q4 were described. Homogeneous early blue CL Q1 with initial emission spectra at 380 and 500 nm was observed at the Čelina deposit with typical titanium concentrations in the range of 20–50 ppm. Hydrothermal quartz at Mokrsko-West, which also includes early Q1, late subhedral faces of yellow CL Q2, and microfissures of greenish CL Q3 (both 570 nm), is characterized by titanium depletion. The titanium concentration is comparable to previous studies of crystallization temperatures proving titanium concentration in quartz as a good geothermal indicator. Q4, developed in microfissures only at Čelina, has no visual CL effect. Mokrsko-West is specific in comparison to Mokrsko-East and Čelina by germanium enrichments in hydrothermal quartz (up to 17 ppm) and the presence of fluorite. Tectonic (sheeted veinlets system, regional tectonic setting) and geochemical (germanium in quartz, the presence of fluorite) characteristics of the quartz veins link the late mineralization stages at the Mokrsko-West deposit to the temporally related Blatná intrusive suite.

scholarly journals Genetic relationship between greisenization and Sn-W mineralizations in vein and greisen deposits: Insights from the Panasqueira deposit (Portugal)

2021 ◽  
Vol 192 ◽  
pp. 2
Author(s):  
Gaëtan Launay ◽  
Stanislas Sizaret ◽  
Philippe Lach ◽  
Jérémie Melleton ◽  
Éric Gloaguen ◽  
...  
Keyword(s):  
Trace Elements ◽  
Hydrothermal System ◽  
Quartz Vein ◽  
Major And Trace Elements ◽  
Multivariate Statistical ◽  
Quartz Veins ◽  
Hydrothermal Quartz ◽  
Multivariate Statistical Approach ◽  
Cooling Trend ◽  
Ti In Quartz

The W-Sn Panasqueira ore deposit is a magmatic-hydrothermal system, which includes a high grade quartz-vein type mineralization and underneath disseminated greisen-type mineralization located in the upper part of a two-mica granite. We investigate genetic and chronological relationships between greisenization of the Panasqueira granite and the formation of ore-bearing quartz veins by monitoring major and trace elements variations in quartz-muscovite assemblages composing the two-mica granite, greisen and ore-bearing quartz veins. Greisen is marked by an overall depletion in Mg, Ti, Ca, Na, Ba, Sr, REE and enrichment in Fe, Li, Rb, Cs, Sn, W that reflect the breakdown of feldspars and biotite and implication of W-Sn-bearing fluids during greisenization. Muscovite from greisen and mineralized quartz veins are enriched in granophile elements (F, Rb, Cs, Li, Sn, W and Zn) compared to magmatic muscovite from the two-mica granite. Trace elements contents in quartz depict evolutionary trends with progressive enrichment in Ge and B and depletion in Al, Ti and Li between magmatic and hydrothermal quartz that emphasize the progressive evolution and cooling of the magmatic-hydrothermal system of Panasqueira. Multivariate statistical approach applied on quartz and muscovite data demonstrates similarities in composition between quartz and muscovite from greisen with those composing ore-bearing quartz veins. These similarities suggest that greisenization and the formation of mineralized veins result from the same hydrothermal event and derived from the same source of hydrothermal fluids. Apatite from greisen and quartz vein yielded respectively U-Pb ages of 292 ± 10 Ma and 295 ± 5 Ma confirming that greisenization and the formation of mineralized veins occurred roughly at the same time. These ages also overlap with the cooling age of the Panasqueira granite (296 ± 4 Ma), indicating a temporal and genetic link between greisenization, W-Sn mineralization and the granite crystallization. Temperatures of the magmatic-hydrothermal system constrained by Ti-in quartz thermometry depicts a cooling trend from magmatic quartz of granite (700–600 °C) to hydrothermal quartz of greisen (500–400 °C) and veins (450–350 °C). These results provide evidences that greisenization and the formation of W-Sn bearing quartz veins occurred at the magmatic-hydrothermal transition, during which orthomagmatic fluids rich in volatils, incompatible elements and metals (W and Sn) were exsolved at the final stage of solidification of the Panasqueira two-mica granite.

Trace elements in hydrothermal quartz: Relationships to cathodoluminescent textures and insights into vein formation

Geology ◽  
2008 ◽  
Vol 36 (7) ◽  
pp. 547 ◽  
Author(s):  
Brian G. Rusk ◽  
Heather A. Lowers ◽  
Mark H. Reed
Keyword(s):  
Trace Elements ◽  
Hydrothermal Quartz ◽  
Vein Formation

Microanalytical Identification of a New Zr-Nb-Fe Phase

1990 ◽  
Vol 48 (2) ◽  
pp. 132-133
Author(s):  
O.T. Woo ◽  
G.J.C. Carpenter
Keyword(s):  
Trace Elements ◽  
Cold Rolling ◽  
Proportionality Factor ◽  
Tube Material ◽  
X Ray ◽  
Metal Foils ◽  
Arc Melting ◽  
Intermetallic Particles ◽  
Intermetallic Precipitates ◽  
Cold Worked

To study the influence of trace elements on the corrosion and hydrogen ingress in Zr-2.5 Nb pressure tube material, buttons of this alloy containing up to 0.83 at% Fe were made by arc-melting. The buttons were then annealed at 973 K for three days, furnace cooled, followed by ≈80% cold-rolling. The microstructure of cold-worked Zr-2.5 at% Nb-0.83 at% Fe (Fig. 1) contained both β-Zr and intermetallic precipitates in the α-Zr grains. The particles were 0.1 to 0.7 μm in size, with shapes ranging from spherical to ellipsoidal and often contained faults. β-Zr appeared either roughly spherical or as irregular elongated patches, often extending to several micrometres.The composition of the intermetallic particles seen in Fig. 1 was determined using Van Cappellen’s extrapolation technique for energy dispersive X-ray analysis of thin metal foils. The method was employed to avoid corrections for absorption and fluorescence via the Cliff-Lorimer equation: CA/CB = kAB · IA/IB, where CA and CB are the concentrations by weight of the elements A and B, and IA and IB are the X-ray intensities; kAB is a proportionality factor.

XRMF applications of a monolithic, polycapillary, focusing x-ray optic

1996 ◽  
Vol 54 ◽  
pp. 240-241
Author(s):  
D. A. Carpenter ◽  
Ning Gao ◽  
G. J. Havrilla
Keyword(s):  
Trace Elements ◽  
Point Source ◽  
Focal Spot ◽  
Fluorescence Analysis ◽  
X Rays ◽  
Focal Distance ◽  
Spot Diameter ◽  
X Ray ◽  
Focal Spot Diameter

A monolithic, polycapillary, x-ray optic was adapted to a laboratory-based x-ray microprobe to evaluate the potential of the optic for x-ray micro fluorescence analysis. The polycapillary was capable of collecting x-rays over a 6 degree angle from a point source and focusing them to a spot approximately 40 µm diameter. The high intensities expected from this capillary should be useful for determining and mapping minor to trace elements in materials. Fig. 1 shows a sketch of the capillary with important dimensions.The microprobe had previously been used with straight and with tapered monocapillaries. Alignment of the monocapillaries with the focal spot was accomplished by electromagnetically scanning the focal spot over the beveled anode. With the polycapillary it was also necessary to manually adjust the distance between the focal spot and the polycapillary.The focal distance and focal spot diameter of the polycapillary were determined from a series of edge scans.

Trace Elements and Iron in Human Metabolism

1979 ◽  
Vol 7 (6) ◽  
pp. 1330-1331
Author(s):  
E. D. WILLS
Keyword(s):  
Trace Elements ◽  
Human Metabolism

Meat and Meat Products Consumption in Italy: Contribution to Trace Elements, Heme Iron and selected B Vitamins supply

2004 ◽  
Vol 74 (4) ◽  
pp. 247-251 ◽  
Author(s):  
Lombardi-Boccia ◽  
Lanzi ◽  
Lucarini ◽  
Di Lullo
Keyword(s):  
Trace Elements ◽  
Daily Intake ◽  
Meat Products ◽  
Heme Iron ◽  
B Vitamins ◽  
Zinc Intake ◽  
Consumption Frequency ◽  
Iron And Zinc ◽  
Iron Heme ◽  
Daily Intakes

This study was undertaken to estimate the contribution of meat and meat products consumption to the daily intakes of trace elements (Fe, Zn, Cu, Se), heme iron, and selected B vitamins (thiamine, riboflavin, niacin) in Italy. Meat and meat products were selected on the basis of their consumption frequency reported by the most recent nationwide dietary individual survey carried out in Italy (INN-CA study). The daily intakes of total iron and heme iron were 1.65 and 1.13 mg/person/day. Zinc intake was 3.65 mg/person/day. Beef made the main contribution to iron, heme iron, and zinc daily intakes. Copper daily intake was 107.3 mug/person/day, with meat products provided the highest contribution (40 mug/person/day). Daily intake of selenium (7.14 mug/person/day) was provided mainly by poultry consumption. Thiamine intake was 228 mug/person/day, and meat products were the main source (110 mug/person/day). Riboflavin intake was 136 mug/person/day, with both beef and meat products as the main contributors (40 mug/person/day). Niacin intake was 7.53 mg/person/day, and poultry was the main source (2.28 mg/person/day). Meat and meat products were a valuable source of micronutrients, supplying 47, 48, and 24% of zinc, niacin, and thiamin daily requirements, respectively, and over 10% of iron, copper, selenium, and riboflavin daily average requirement values of the italian RDAs calculated for the population involved in the survey (INN-CA study).

Pre-concentration of selected trace elements from seawater by co-precipitation on Mg(OH)2

2003 ◽  
Vol 107 ◽  
pp. 945-948 ◽  
Author(s):  
P. M. Nicolaysen ◽  
E. Steinnes ◽  
T. E. Sjobakk
Keyword(s):  
Trace Elements ◽  
Co Precipitation

Gamma-Ray Spectrometric Analysis of Some Trace Elements in the Human Articular Disc of the Mandible

1963 ◽  
Vol 03 (02) ◽  
pp. 175-182 ◽  
Author(s):  
Bo Bergman ◽  
Rune Söremark
Keyword(s):  
Trace Elements ◽  
Neutron Activation ◽  
Quantitative Data ◽  
Thermal Neutron Flux ◽  
Gamma Ray ◽  
Dry Weight ◽  
Gamma Ray Spectrometry ◽  
Spectrometric Analysis ◽  
Articular Disc ◽  
Group Separation

SummaryBy means of neutron activation and gamma-ray spectrometry the concentrations in the human mandibular articular disc of the following elements have been determined: Na, Mn, Cu, Zn, Rb, Sr, Cd, W, and Au. The discs were obtained at necropsy from seven men and nine women, ranging in age from 56 to 71 years.The activation was carried out in a thermal neutron flux of about 1.7 XlO12 neutrons × cm−2 × sec.−1 for about 20 hours. A chemical group separationwas performed before the gamma-ray spectrometry. Quantitative data based on the dry weight of the cartilage samples were obtained by comparing the photo-peak area of the identified elements with those of appropriate standards.

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