scholarly journals Melting Experiment on Peridotite at High Pressure : from Basalt Magma Genesis to Origin of Peridotite

1988 ◽  
Vol 97 (3) ◽  
pp. 228-233
Author(s):  
Eiichi TAKAHASHI
Keyword(s):  
High Pressure ◽  
Basalt Magma ◽  
Magma Genesis ◽  
Melting Experiment

scholarly journals Study of silica-undersaturated magmas through the Kalsilite- Nepheline-Diopside-Silica system at 4.0 GPa and dry conditions

2018 ◽  
Vol 18 (2) ◽  
pp. 87-102
Author(s):  
Márcio Roberto Wilbert de Souza ◽  
Rommulo Vieira Conceição ◽  
Daniel Grings Cedeño ◽  
Roberto Vicente Schmitz Quinteiro
Keyword(s):  
High Pressure ◽  
Solid Solutions ◽  
Negative Correlation ◽  
Stability Field ◽  
Thermal Barrier ◽  
High Pressure And Temperature ◽  
Alkaline Magma ◽  
Magma Genesis ◽  
Dry Conditions ◽  
The Stability

This study experimentally investigates the Kalsilite-Nepheline-Diopside-Silica system at high pressure and temperature, with emphasis on silica-undersaturated volume (leucite-nepheline-diopside — Lct-Nph-Di; and kalsilite-nepheline-diopside — Kls + Nph + Di — planes), at 4.0 GPa (~120 km deep), temperatures up to 1,400ºC and dry conditions, to better understand the influence of K2O, Na2O, and CaO in alkali-rich silica-undersaturated magma genesis. In the Lct-Nph-Di plane, we determined the stability fields for kalsilite (Klsss), nepheline (Nphss) and clinopyroxene (Cpxss) solid solutions, wollastonite (Wo) and sanidine (Sa); and three piercing points: (i) pseudo-eutectic Kls + Nph + Di + liquid (Lct62Nph29Di9) at 1,000ºC; (ii) Kls + Sa + (Di + Wo) + liquid (Lct75Nph22Di2) at 1,200ºC; and (iii) pseudo-eutectic Kls + Di + Wo + liquid (Lct74Nph17Di9) at 1,000ºC. Kalsilite stability field represents a thermal barrier between ultrapotassic/potassic vs. sodic compositions. In the plane Kls-Nph-Di, we determined the stability fields for Klsss, Nphss and Cpxss and two aluminous phases in smaller proportions: spinel (Spl) and corundum (Crn). This plane has a piercing point in Kls + Nph + Di(± Spl) + liquid (Kls47Nph43Di10) at 1,100ºC. Our data showed that pressure extends K dissolution in Nph (up to 39 mol%) and Na in Kls (up to 27 mol%), and that these solid solutions, if present, determinate how much enriched in K and Na an alkaline magma will be in an alkaline-enriched metasomatic mantle. Additionally, we noted positive correlation between K2O and SiO2 concentration in experimental melts, negative correlation between CaO and SiO2, and no evident correlation between Na2O and SiO2. 

Density of high-Ti basalt magma at high pressure and origin of heterogeneities in the lunar mantle

2010 ◽  
Vol 299 (3-4) ◽  
pp. 285-289 ◽  
Author(s):  
Tatsuya Sakamaki ◽  
Eiji Ohtani ◽  
Satoru Urakawa ◽  
Akio Suzuki ◽  
Yoshinori Katayama ◽  
...  
Keyword(s):  
High Pressure ◽  
Basalt Magma

scholarly journals Basalt Magma Genesis at Convergent Plate

1988 ◽  
Vol 97 (3) ◽  
pp. 178-183
Author(s):  
Yoshiyuki TATSUMI
Keyword(s):  
Basalt Magma ◽  
Magma Genesis

High pressure-temperature point on an Archaean geotherm, implied magma genesis by crustal anatexis, and consequences for garnet-pyroxene thermometry and barometry

1978 ◽  
Vol 288 (1355) ◽  
pp. 441-456 ◽  
Keyword(s):  
Heat Transfer ◽  
High Pressure ◽  
High Temperatures ◽  
Granulite Facies ◽  
Magma Ascent ◽  
Crustal Anatexis ◽  
Magma Genesis ◽  
Gneiss Complex ◽  
Present Complex ◽  
Very High

The presence of metasediments indicates derivation of at least part of the 2.8 Ga old Scourie gneiss complex from a wet supracrustal series. The dry, large ion lithophile element depleted character of the present complex indicates an episode of anatexis and removal of granitic magmas during the evolution of the gneisses. This paper concentrates on the evidence for very high temperatures of metamorphism, the nature of the processes of anatexis and magma ascent and their implications for heat transfer in the Archaean crust; finally it reviews the credibility of some garnetpyroxene thermometers and barometers in the light of the external constraints placed upon possible solutions by the crustal setting of these granulite facies gneisses.

Picritic basalts from the Palaeocene lava field of west-central Skye, Scotland: evidence for parental magma compositions

1994 ◽  
Vol 58 (392) ◽  
pp. 347-356 ◽  
Author(s):  
Brian R. Bell ◽  
Ian T. Williamson
Keyword(s):  
High Pressure ◽  
Compositional Data ◽  
Parental Magma ◽  
Mineral Chemistry ◽  
Chrome Spinel ◽  
Basalt Magma ◽  
Lava Field ◽  
Igneous Complex ◽  
West Central ◽  
Magma Compositions

AbstractMineral chemistry and whole-rock compositional data are reported for two lavas of picritic basalt from the Palaeocene lava field of west-central Skye, Scotland. Whole-rock compositions for both flows plot on Thompson's (1982) 9 kbar cotectic for olivine + plagioclase + clinopyroxene + liquid. Both flows contain highly forsteritic olivine phenocrysts (c. Fo89), which enclose early-precipitated crystals of chrome-spinel (Al2O3: c. 25 wt.%; Cr2O3: c. 36 wt.%; FeO + Fe2O3: c. 20 wt.%; MgO: c. 15 wt.%). The olivine compositions indicate equilibrium with picritic basalt magma compositions, as represented by the whole-rock compositions of both lavas. A high-pressure origin for the chrome-spinels is suspected on the basis of their textural association and aluminous composition. Compositional comparisons between the whole-rock and mineral chemistry characteristics of both flows and a picritic basalt chill facies of the temporally- and spatially-associated Rum Igneous Complex suggests that similar parental magmas were involved.

High-pressure freezing of cells in suspension for low-voltage scanning electron microscopy (LVSEM)

1991 ◽  
Vol 49 ◽  
pp. 64-65
Author(s):  
Marek Malecki ◽  
James Pawley ◽  
Hans Ris
Keyword(s):  
Electron Microscopy ◽  
High Pressure ◽  
Low Voltage ◽  
Culture Media ◽  
Cell Structure ◽  
Freeze Substitution ◽  
Ice Crystal ◽  
High Pressure Freezing ◽  
Cell Culture Media ◽  
Voltage Scanning

The ultrastructure of cells suspended in physiological fluids or cell culture media can only be studied if the living processes are stopped while the cells remain in suspension. Attachment of living cells to carrier surfaces to facilitate further processing for electron microscopy produces a rapid reorganization of cell structure eradicating most traces of the structures present when the cells were in suspension. The structure of cells in suspension can be immobilized by either chemical fixation or, much faster, by rapid freezing (cryo-immobilization). The fixation speed is particularly important in studies of cell surface reorganization over time. High pressure freezing provides conditions where specimens up to 500μm thick can be frozen in milliseconds without ice crystal damage. This volume is sufficient for cells to remain in suspension until frozen. However, special procedures are needed to assure that the unattached cells are not lost during subsequent processing for LVSEM or HVEM using freeze-substitution or freeze drying. We recently developed such a procedure.

Sign in / Sign up

Export Citation Format

Share Document