Petrology of a plagioclase-bearing olivine websterite from the Gorringe Bank (northeastern Atlantic Ocean)

1988 ◽  
Vol 25 (4) ◽  
pp. 557-569 ◽  
Author(s):  
Giancarlo Serri ◽  
Réjean Hébert ◽  
Roger Hekinian
Keyword(s):  
Solidus Temperature ◽  
Parental Magma ◽  
Minor Element ◽  
Element Distribution ◽  
Rock Composition ◽  
Natural Systems ◽  
S 100 ◽  
Compositional Variations ◽  
A Minor ◽  
Northeastern Atlantic

Samples of plagioclase olivine websterite included in variously serpentinized harzburgite and lherzolite tectonites were collected by submersible on the northwest flank of the Gettysburg Seamount near 36°N in the northeastern Atlantic. The websterite exhibits a coarse porphyroclastic texture (70% porphyroclasts), and the composition of the pyroxene shows a progressive re-equilibration with decreasing temperature (and probably pressure) under anhydrous conditions from a near-solidus temperature of ~1250 °C (porphyroclasts) down to ~700 °C (granoblasts). In situ observations, as well as textural, mineralogical, and chemical evidence, suggest that the websterite can best be interpreted as a heteradcumulate rock that crystallized on the walls of narrow conduits from a MORB type magma flowing through the residual tectonites.The Mg #'s (= 100 × Mg/(Mg + Fe2+)) of coexisting clinopyroxene, orthopyroxene, and olivine (91.5–90.5, 90.0–89.7, and 89.5–88.5, respectively), the plagioclase composition (An88.7–87.9), and the mineral minor-element distribution are not compatible with the crystallization at low pressure of the websterite from N-MORB type parental magma. Instead, the calculated composition of the liquid in equilibrium with the websterite's most magnesian minerals and the bulk-rock composition are more akin to those of a poorly differentiated T-MORB than of N-MORB parental magma. Phase relations and mineral compositions produced by anhydrous melting experiments for synthetic and natural systems indicate that the pressure of crystallization of the plagioclase olivine websterite is constrained within the narrow range of 7–10 kbar. It is thought that fractionation of websterite is probably a minor but significant petrologic factor of MORB type magma differentiation. It could explain some of the compositional variations observed in magnesian MORB.

SATOUMI APPROACH FOR REALIZING SUSTAINABLE COASTAL USE IN A RIASTYPE BAY: A CASE OF SHIZUGAWA BAY IN SANRIKU COAST HIT BY THE HUGE TSUNAMI ON 11 MARCH 2011

2017 ◽  
Author(s):  
Teruhisa Komatsu ◽  
Teruhisa Komatsu ◽  
Shuji Sasa ◽  
Shuji Sasa ◽  
Shigeru Montani ◽  
...  
Keyword(s):  
Local Governments ◽  
Minor Element ◽  
Coupling Model ◽  
Sanriku Coast ◽  
High Productivity ◽  
Biological Coupling ◽  
Miyagi Prefecture ◽  
Human Use ◽  
A Minor ◽  
Aquaculture Facilities

Rias-type bays are one of the most common coasts in Japan where aquacultures have been active due to sheltered geological shape with a deep bottom. The huge tsunami hit Sanriku Coast consisting of open rias-type bays near the epicenter facing Pacific Ocean on 11 March 2011. For recovering Sanriku Coast, it is important to include sustainability in its program. Satoumi is defined as the human use and management of coastal seas for high productivity while maintaining high biodiversity. Therefore, we proposed Satoumi approach to an open rias-type bay, Shizugawa Bay, in southern Sanriku Coast. We conducted scientific researches on mapping of coastal habitats and aquaculture facilities, hydrography, and material flows of nutrients, a minor element (Fe) and organic matters in the bay including those from the rivers and from the offshore waters. At the same time, Committee for Shizugawa Bay Management of Fishermen’s Cooperative of Miyagi Prefecture decided to decrease in aquaculture facilities for sustainable development of aquaculture. Based on these data, a physical-biological coupling model was used for calculating the number of aquaculture facilities that are suitable not only for yields but also for environments. These researches were established on strong collaborations among a fishermen’s’ cooperative, local governments and scientists. Results of this practice may help to realize sustainable coastal use of a rias-type bay.

Minor-Element Distribution in Olivine

1970 ◽  
Vol 78 (3) ◽  
pp. 304-325 ◽  
Author(s):  
Tom Simkin ◽  
J. V. Smith
Keyword(s):  
Minor Element ◽  
Element Distribution

scholarly journals Chlorine as a Discriminant Element to Establish the Provenance of Central Mediterranean Obsidians

2020 ◽  
Vol 6 (1) ◽  
pp. 454-476
Author(s):  
Franco Foresta Martin ◽  
Silvio G. Rotolo ◽  
Manuela Nazzari ◽  
Maria Luisa Carapezza
Keyword(s):  
Electron Microprobe ◽  
Minor Element ◽  
Igneous Rocks ◽  
Chlorine Concentration ◽  
Silicate Melts ◽  
Alkali Content ◽  
Central Mediterranean ◽  
A Minor

Abstract Chlorine is a minor element present in obsidians in quantities greater than in average igneous rocks. The chlorine concentration in obsidians is generally low, of the order of tenths of wt %, but it exhibits an appreciable differentiation among geological sources. Despite these characteristics, chlorine has rarely been taken into consideration as a possible indicator of obsidian provenance and it does not appear in the chemical analytical tables accompanying the geochemical characterisation of obsidian samples. In this work, after an overview of chlorine geochemistry and cycle, we present thirty-one new electron microprobe (EPMA) analyses, including Cl, of geologic obsidians sampled from the four sources of the Central Mediterranean, exploited in prehistoric times (Monte Arci, Palmarola, Lipari and Pantelleria). The results are compared with 175 new EPMA analyses, including Cl, of archaeological obsidians already characterised in previous work and of known provenance. As such it was possible to ascertain that each source has a characteristic chlorine concentration, showing the utility of its use in the studies of obsidian provenance. Furthermore, given that the solubility of chlorine in silicate melts is correlated to its alkali content, in particular sodium, we assessed the efficacy of simple binary graphs Cl vs Na2O to better constrain the provenance of the obsidian samples.

Rare-earth and minor element distribution and petrographic features of fluorites and associated Mesozoic limestones of northwestern Sicily

1981 ◽  
Vol 32 (1-4) ◽  
pp. 255-269 ◽  
Author(s):  
A. Bellanca ◽  
P. Di Salvo ◽  
P. Möller ◽  
R. Neri ◽  
F. Schley
Keyword(s):  
Rare Earth ◽  
Minor Element ◽  
Element Distribution

scholarly journals Rinkite–nacareniobsite-(Ce) solid solution series and hainite from the Ilímaussaq alkaline complex: occurrence and compositional variation

2014 ◽  
Vol 62 ◽  
pp. 1-15
Author(s):  
Jørn G. Rønsbo ◽  
Henning Sørensen ◽  
Encarnacion Roda-Robles ◽  
François Fontan ◽  
Pierre Monchoux
Keyword(s):  
Solid Solution ◽  
Electron Microprobe ◽  
Compositional Variation ◽  
Solid Solution Series ◽  
Alkaline Complex ◽  
Full Extension ◽  
X Ray ◽  
Solution Series ◽  
Compositional Variations ◽  
A Minor

In the Ilímaussaq alkaline complex, minerals from the rinkite–nacareniobsite-(Ce) solid solution series have been found in pulaskite pegmatite, sodalite foyaite, naujaite and naujaite pegmatite from the roof sequence, and in marginal pegmatite, kakortokite and lujavrite from the floor sequence. The electron microprobe analyses embrace almost the full extension of the solid solution series and confirm its continuity. The solid solution series shows similar compositional variations in the roof and floor sequences: Rinkite members of the series are found in the less evolved rocks in the two sequences, whereas nacareniobsite-Ce members occur in the most evolved rocks and pegmatites in the two sequences. The REE (+Y) content varies from 0.83 atoms per formula unit (apfu) in rinkite from pulaskite pegmatite to 1.31 apfu in nacareniobsite-(Ce) from naujaite pegmatite. The main substitution mechanisms in the solid solution series investigated in this work are 2Ca2+ = Na+ + REE3+ and Ti4+ + Ca2+ = Nb5+ + Na+. The increased contents of Nb5+ and REE3+ are only to a minor degree compensated through the F1– = O2– substitution. The chondrite normalised REE patterns of the minerals develop in a similar way in the two sequences, showing relative La-enrichment and Y-depletion from the less to the most evolved rocks. Hainite has not previously been found in the Ilímaussaq complex. It was here identified in a pulaskite pegmatite sample by a combination of X-ray diffraction giving the unit cell dimensions a = 9.5923(7) Å, b = 7.3505(5) Å, c = 5.7023(4) Å, α = 89.958(2)°, β = 100.260(1)°, γ = 101.100(2)°, and X-ray powder pattern and electron microprobe data giving the empirical formula (Ca1.62 Zr0.16Y 0.22) (Na0.87Ca1.11) (Ca 1.65 REE0.35)Na(Ti0.81Nb0.09Fe0.08 Zr0.02)(Si2O7)2O0.99F2.96. Based on published and the present data it is documented that minerals from the hainite-götzenite solid solution series show a compositional variation between the ideal end members (Y,REE,Zr)Na2Ca4Ti(Si2O7)2OF3 and NaCa6Ti(Si2O7)2OF3.

scholarly journals The Motive Of Crime In Foreign Law: A Comparative Legal Analysis

2019 ◽  
pp. 145-154
Author(s):  
Yu.V. Leka
Keyword(s):  
Legal Status ◽  
State Level ◽  
Minor Element ◽  
Legal Analysis ◽  
Foreign Countries ◽  
European Standards ◽  
Basic Approaches ◽  
A Minor ◽  
Criminal Legislation ◽  
Subjective Side

The article substantiates the need to carry out a comparative legal analysis of Ukrainian and foreign legislation on fixing the motive of the crime and its criminal- legal significance. Comparative analysis of the laws of foreign countries is made taking into account the membership of countries in the legal systems. The research of the legal status of the motive of crime in the legislation of foreign countries was carried out on the basis of consideration of basic acts of criminal legislation approved at the state level by the higher legislative bodies of a state. The analysis of various approaches to determining the motive of the crime based on the works of foreign and domestic scientists. On the basis of consideration of normative legal acts of criminal nature of foreign countries, the main terms, which indicate the motive of the crime are defined. The basic approaches of fixing the motive of crime in the legislation of foreign countries are defined and the ways of improvement of the Ukrainian legislation in this matter are proposed. It has been established that the legislation of some countries clearly traces the role of motive as a circumstance aggravating punishment and as a sign that must be taken into account directly in sentencing. In spite of this, most countries still hold a position of indifference to the motive of the crime, recognizing it as a minor element of the subjective side of the crime. It is established that the position of the Ukrainian legislator on the optionality of the sign of motive among other constituents of the subjective side of the crime and the obligatory sign among the elements of evidence in the criminal process is quite logical and justified. But many aspects related to the motive for the crime must be refined. Ukrainian legislation, including criminal law, become more progressive every year and meets European standards.

Silurian acastacean trilobites of the Americas

1993 ◽  
Vol 67 (4) ◽  
pp. 535-548 ◽  
Author(s):  
Gregory D. Edgecombe
Keyword(s):  
Minor Element ◽  
South American ◽  
A Minor ◽  
North And South

Species of the superfamily Acastacea constitute a minor element of North and South American Silurian trilobite faunas. Phacopidina? obsoleta (Ulrich and Delo) (Llandovery, Tennessee) provides the sole Silurian record of the “kloucekiine” grade (Acastacea s.l.); a lectotype is designated for this species. Acaste birminghamensis Norford (mid Llandovery, Alabama) lacks synapomorphies of post-Llandovery Acastidae s.s. (=Acastinae + “Acastavinae” + Asteropyginae), and is the basis for Llandovacaste n. gen. (Acastidae s.l.). A well-preserved sample of Andinacaste cf. A. ledgrandi Eldredge and Braniša from the Catavi Formation (Ludlow–Přídolí), Bolivia, displays apomorphic characters of the genal spines and hypostome shared with Devonian calmoniids. Coaptative structures, including vincular furrow/pits and “bifurcated” thoracic pleural tips, are documented for Andinacaste; similar enrollment morphologies arose in other acastomorph calmoniids. Poorly known Llandovery acastaceans from Paraguay and Venezuela may represent Andinacaste. Acaste zerinae n. sp. from the Pembroke Formation (Přídolí) of Maine is closely comparable to British late Wenlock A. downingiae (Murchison). The Australian Gedinnian acastine placed in Phacopinae indet. longisulcata (Shergold) is designated Acaste lokii n. sp.

How can a minor element added to a binary amorphous alloy simultaneously improve the plasticity and glass-forming ability?

2013 ◽  
Vol 61 (17) ◽  
pp. 6597-6608 ◽  
Author(s):  
Hong-Kyu Kim ◽  
Mirim Lee ◽  
Kwang-Ryeol Lee ◽  
Jae-Chul Lee
Keyword(s):  
Amorphous Alloy ◽  
Minor Element ◽  
Glass Forming Ability ◽  
Glass Forming ◽  
A Minor

First-Principles Study of Atomic Hydrogen and Oxygen Adsorption on Doped-Iron Nanoclusters

2016 ◽  
Author(s):  
Nishith K. Das ◽  
T. Shoji
Keyword(s):  
Density Functional ◽  
Hydrogen Adsorption ◽  
Density Functional Theory Calculations ◽  
Minor Element ◽  
Oxygen Adsorption ◽  
Ground State Structure ◽  
Small Contribution ◽  
Functional Theory ◽  
Strong Hybridization ◽  
A Minor

Density functional theory calculations have been used to calculate the ground state structure and oxygen and hydrogen adsorption properties of the pure and doped-iron nanoclusters. Small atomic clusters containing two to six atoms have been considered and a single Fe atom has replaced by a minor element i.e. Zr, Ti, and Sc. Doping of a minor element increases the cluster stability and octahedron Fe5Zr is the most stable structure within this study. Zr- and Sc-doped clusters have the highest oxygen and hydrogen adsorption energy. The electronic structure shows a strong hybridization between the metal 3d and oxygen 2p orbitals with a small contribution from metal 4s and 3p orbitals. Additionally, H s and metal 4s states form a new peak below the Fermi energy and a small modification is observed for 3d orbitals near the Fermi level. A small amount of Zr- and Sc-doping into the Fe-based alloys might improve the oxide film adherence.

Thermodynamic Terms

1993 ◽  
Author(s):  
Greg M. Anderson ◽  
David A. Crerar
Keyword(s):  
Solar System ◽  
Surface Effects ◽  
Equilibrium States ◽  
Minor Role ◽  
Natural Systems ◽  
Gravitational Fields ◽  
Energy Transfers ◽  
A Minor ◽  
The Universe

Thermodynamics is the science that deals with energy differences and transfers between systems, and with systematizing and predicting what transfers will take place. Such fundamental topics naturally find application in all branches of science, and have been of interest since the earliest beginnings of science. In general, since we are dealing with energy transfers between systems, most of what follows has to do with what the entities (equilibrium states) are from which and to which energy is being transferred, and the boundaries or walls through which or by which the transfer is effected. It is in these considerations that we first see the differences between natural systems (reality) and our models of these systems. System refers to any part of the universe we care to choose, whether the contents of a crucible, a cubic centimeter in the middle of a cooling magma, or the solar system. Depending on the nature of the discussion, it must be more or less clearly defined and separated (in fact or in thought) from the rest of the universe, which then becomes known as the system's surroundings. At the outset, we will effect an enormous simplification by considering only systems that are unaffected by electrical, magnetic, or gravitational fields, and in which particles are sufficiently large that surface effects can be neglected. Each of these topics can be incorporated into the basic thermodynamic network to be developed, but it is a nuisance to carry them all along from the beginning, and a great deal can be done without considering them at all. More exactly, a great deal can be done if we choose to consider systems where these fields and surfaces play a minor role. Clearly we would not get very far if we tried to understand the solar system without considering gravitational fields. Chemical and geochemical problems however commonly do not need to have these factors included in order to be understood. In science, when a problem or a phenomenon such as the solar system or the boiling of water is said to be understood, what is usually meant is that we have a model of the phenomenon which is satisfactory at some level, and about which virtually all scientists agree.

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