scholarly journals Crystal mush dykes as conduits for mineralising fluids in the Yerington porphyry copper district, Nevada

2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Lawrence C. Carter ◽  
Ben J. Williamson ◽  
Simon R. Tapster ◽  
Catia Costa ◽  
Geoffrey W. Grime ◽  
...  
Keyword(s):  
Low Temperature ◽  
Cross Section ◽  
Porphyry Copper ◽  
Similar Type ◽  
Interconnected Network ◽  
Crystal Mush ◽  
Porphyry Deposit ◽  
Hydrothermal Quartz ◽  
Miarolitic Cavities

AbstractPorphyry-type deposits are the world’s main source of copper and molybdenum and provide a large proportion of gold and other metals. However, the mechanism by which mineralising fluids are extracted from source magmas and transported upwards into the ore-forming environment is not clearly understood. Here we use field, micro-textural and geochemical techniques to investigate field relationships and samples from a circa 8 km deep cross-section through the archetypal Yerington porphyry district, Nevada. We identify an interconnected network of relatively low-temperature hydrothermal quartz that is connected to mineralised miarolitic cavities within aplite dykes. We propose that porphyry-deposit-forming fluids migrated from evolved, more water-rich internal regions of the underlying Luhr Hill granite via these aplite dykes which contained a permeable magmatic crystal mush of feldspar and quartz. The textures we describe provide petrographic evidence for the transport of fluids through crystal mush dykes. We suggest that this process should be considered in future models for the formation of porphyry- and similar-type deposits.

Silicate-germanate K2Y[(Si3Ge)O10(OH)] with unusual complex corrugated layer and its correlation to ring silicate gerenite and chain silicate chkalovite

2020 ◽  
Vol 235 (4-5) ◽  
pp. 167-172
Author(s):  
Anastasiia P. Topnikova ◽  
Elena L. Belokoneva ◽  
Olga V. Dimitrova ◽  
Anatoly S. Volkov ◽  
Leokadiya V. Zorina
Keyword(s):  
Low Temperature ◽  
Cross Section ◽  
Complex Anion ◽  
Diffraction Experiment ◽  
X Ray Diffraction ◽  
Unit Cell Parameters ◽  
X Ray ◽  
Cell Parameters ◽  
Chain Silicate ◽  
Novel Complex

AbstractA new silicate-germanate K2Y[(Si3Ge)O10(OH)] was synthesized hydrothermally in a system Y2O3:GeO2:SiO2 = 1:1:2 (T = 280 °C; P = 90–100 atm.); K2CO3 was added to the solution as a mineralizer. Single-crystal X-ray diffraction experiment was carried out at low temperature (150 K). The unit cell parameters are a = 10.4975(4), b = 6.9567(2), c = 15.4001(6) Å, β = 104.894(4)°; V = 1086.86(7) Å3; space group is P 21/c. A novel complex anion is presented by corrugated (Si,Ge) tetrahedral layers connected by couples of YO6 octahedra into the mixed microporous framework with the channels along b and a axes, the maximal size of cross-section is ~5.6 Å. This structure has similarity with the two minerals: ring silicate gerenite (Ca,Na)2(Y,REE)3Si6O18 · 2H2O and chain silicate chkalovite Na2BeSi2O6. Six-member rings with 1̅ symmetry as in gerenite are distinguished in the new layer. They are mutually perpendicular to each other and connected by additional tetrahedra. Straight crossing chains in chkalovite change to zigzag four-link chains in the new silicate-germanate layer.

Multipod ZnO Nanoforms: Low Temperature Synthesis and Characterization

2007 ◽  
Vol 7 (2) ◽  
pp. 689-695 ◽  
Author(s):  
Tandra Ghoshal ◽  
Soumitra Kar ◽  
Subhajit Biswas ◽  
Gautam Majumdar ◽  
Subhadra Chaudhuri
Keyword(s):  
Low Temperature ◽  
Field Emission ◽  
Cross Section ◽  
Thermal Evaporation ◽  
Synthesis And Characterization ◽  
Low Temperature Synthesis ◽  
Temperature Synthesis ◽  
Optical Absorbance ◽  
Higher Temperature ◽  
Emission Studies

ZnO nanotetrapods were synthesized by a simple thermal evaporation of Zn powder at a relatively low temperature ∼600 °C. The tetrapods have four legs with hexagonal cross-section. Interpenetrating growth was observed in some of these nanotetrapods. Multipod ZnO nanoforms were produced at higher temperature. The optical characterizations such as optical absorbance, photoluminescence and Raman spectroscopy reveal excellent crystal qualities of these nanoforms. The field emission studies indicated that these nanoforms could be utilized in field emission based devices.

scholarly journals Controls on timing of exhumation and deformation in the northern Peruvian eastern Andean wedge as inferred from low-temperature thermochronology and balanced cross section

Tectonics ◽  
2015 ◽  
Vol 34 (4) ◽  
pp. 715-730 ◽  
Author(s):  
Adrien Eude ◽  
Martin Roddaz ◽  
Stéphanie Brichau ◽  
Stéphane Brusset ◽  
Ysabel Calderon ◽  
...  
Keyword(s):  
Low Temperature ◽  
Cross Section ◽  
Balanced Cross Section

Kamphaugite-(Y) from La Cabrera massif, Spain: a low-temperature hydrothermal Y-REE carbonate

2006 ◽  
Vol 70 (4) ◽  
pp. 397-404 ◽  
Author(s):  
J. González del Tánago ◽  
A. La Iglesia ◽  
A. Delgado
Keyword(s):  
Low Temperature ◽  
Carbon Source ◽  
Alkali Feldspar ◽  
Hydrothermal Activity ◽  
Average Composition ◽  
Central System ◽  
Free Surfaces ◽  
Spanish Central System ◽  
Miarolitic Cavities ◽  
Very Low Temperature

AbstractKamphaugite-(Y) occurs as white to cream-coloured spherical to semi-spherical aggregates of radial crystals in the La Cabrera granitic pluton (Spanish Central System). It mainly occurs on the free surfaces of alkali feldspar, quartz, calcite, kainosite-(Y) and laumontite, and inside miarolitic cavities. La Cabrera kamphaugite-(Y) has an average composition of Ca0.94Y0.89REE0.21(CO3)2 [F0.05(OH)0.95]·1.19H2O. Negative δ13CV-PDB values (–14 to –15‰) indicate a meteoric carbon source. Textural relations between kamphaugite-(Y) and coexisting minerals, its relatively high δ18OV-SMOW values (+25 to +26‰), and the occurrence of laumontite inclusions in kamphaugite-(Y), point to a genesis at < 50°C during very low-temperature post-magmatic hydrothermal activity.

Steel Tube Bending with a Filling Medium of Fiber-Reinforced Ice (FRI)

2016 ◽  
Vol 703 ◽  
pp. 11-16 ◽  
Author(s):  
Takahiro Ohashi
Keyword(s):  
Low Temperature ◽  
Cross Section ◽  
Steel Tube ◽  
Filling Material ◽  
Fiber Reinforced ◽  
Compression Tests ◽  
Tube Bending ◽  
Steel Tubes ◽  
Crushing Strength ◽  
Temperature Melting

This paper proposes a new filling material, fiber-reinforced ice (FRI), for tube bending. In tube bending, lead and low temperature melting alloys have conventionally been utilized as the filling medium to prevent defects and to alleviate flattening of the tube’s cross section. However, these alloys are usually harmful to the environment (e.g., Pb, Bi-Pb-Sn-In, or Pb-Cd system alloys) or are expensive (e.g., In-Sn system alloys). In this study, the author utilized ice reinforced with the fiber of wastepaper for 3-point bending of JIS G 3452 SGP 32A steel tubes. Compression tests were conducted to analyze whether these tubes have crushing strength comparable to that of conventional fillings and sufficient ductility in low-speed deformation. The filling medium with more fiber effectively yielded less flattening.

scholarly journals First measurement of the hydrogen spin-exchange collision cross-section in the low temperature region

2008 ◽  
Vol 48 (3) ◽  
pp. 343-350 ◽  
Author(s):  
C. Baumgarten ◽  
B. Braun ◽  
M. Capiluppi ◽  
G. Ciullo ◽  
P. F. Dalpiaz ◽  
...  
Keyword(s):  
Low Temperature ◽  
Cross Section ◽  
Temperature Region ◽  
Spin Exchange ◽  
Collision Cross Section ◽  
Exchange Collision

Characterization of stacked dielectric structures by TEM, electron holography and electron energy loss spectroscopy

1992 ◽  
Vol 50 (2) ◽  
pp. 1430-1431
Author(s):  
G. Waytena ◽  
J.K. Weiss ◽  
P. Rez
Keyword(s):  
Low Temperature ◽  
Cross Section ◽  
Chemical Vapour ◽  
Single Layer ◽  
Compositional Analysis ◽  
Nitride Layer ◽  
Effective Dielectric Constant ◽  
Temperature Growth ◽  
Low Temperature Growth ◽  
Structural Characterisation

Thinner gate oxide regions, less than 100Å wide, are needed as MOS devices are scaled down in size to improve performance and increase the number of devices per chip. Triple layer dielectrics, in which a Si3N4 film is embedded between two SiO2 layers, are being investigated since the nitride layer provides a better diffusion barrier against dopants, metals and impurities as well as higher effective dielectric constant than a single layer of SiO2. To minimise atom diffusion, low temperature growth techniques such as Remote Plasma Enhanced Chemical Vapour Deposition (RPECVD) are being considered. As low temperature growth is not an equilibrium process non-stochiometric compositions can be formed. The aim of this work is to investigate structural characterisation of these layers in cross section by TEM and compositional analysis by PEELS.Two oxide-nitride-oxide (ONO) structures, both with nominally 50Å of nitride sandwiched between 10Åoxide layers in one specimen (10-50-10), and 30Å oxide layers in the second specimen (30-50-30) were grown by RPECVD at Research Triangle Institute. Cross section TEM specimens were prepared in according to standard procedures.

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