Low-pressure crustal anatexis: the significance of spinel and cordierite from metapelitic assemblages at Nanga Parbat, northern Parkistan

The Kisseynew domain within the central Trans-Hudson orogen constitutes a high-temperature (T) and low- to mediumpressure (P) metasedimentary belt characterized by uniform peak metamorphic conditions of 750 ± 50 °C and 56 kbar (1 kbar = 100 MPa). To investigate the thermal evolution of the Kisseynew domain 1-dimensional thermal modelling was conducted for a range of thermal parameters, including the effects of exhumation and incorporating current information about the crustal architecture. The results show that tectonic thickening of the sedimentary pile to ~40 km, consistent with present-day thickness estimates and erosional levels, is capable of producing enough crustal heating to melt the base of the sedimentary pile, advect heat to shallower crustal levels, and produce the observed PT conditions. Deep-seated mantle heat sources, though not excluded, are not required.

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Garnet-bearing leucogranite in the El-Hudi area, southern Egypt: evidence of crustal anatexis during Pan-African low pressure regional metamorphism

Journal of African Earth Sciences ◽

10.1016/s0899-5362(01)80062-2 ◽

2001 ◽

Vol 33 (2) ◽

pp. 245-259 ◽

Cited By ~ 14

Author(s):

A.M. Moghazi ◽

M.A. Hassanen ◽

M.H. Hashad ◽

F.H. Mohamed

Keyword(s):

Regional Metamorphism ◽

Low Pressure ◽

Crustal Anatexis ◽

Pan African

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Effects of Electrical Discharges in Low Pressure Gases on the Morphology of Polyethylene Crystals

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100052730 ◽

1974 ◽

Vol 32 ◽

pp. 544-545

Author(s):

L.H. Bolz ◽

D.H. Reneker

Keyword(s):

Power Distribution ◽

Electrical Discharge ◽

Dielectric Breakdown ◽

Ionic Species ◽

Low Pressure ◽

Polymer Surfaces ◽

Electrical Discharges ◽

Adhesive Bonds ◽

Power Distribution Lines ◽

Modification Of The Surface

The attack, on the surface of a polymer, by the atomic, molecular and ionic species that are created in a low pressure electrical discharge in a gas is interesting because: 1) significant interior morphological features may be revealed, 2) dielectric breakdown of polymeric insulation on high voltage power distribution lines involves the attack on the polymer of such species created in a corona discharge, 3) adhesive bonds formed between polymer surfaces subjected to such SDecies are much stronger than bonds between untreated surfaces, 4) the chemical modification of the surface creates a reactive surface to which a thin layer of another polymer may be bonded by glow discharge polymerization.

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Field ion microscopy

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100104236 ◽

1988 ◽

Vol 46 ◽

pp. 434-435

Author(s):

Gert Ehrlich

Keyword(s):

Low Temperature ◽

Sample Surface ◽

Low Pressure ◽

Radius Of Curvature ◽

Field Ion Microscopy ◽

Phosphor Screen ◽

Ion Microscopy ◽

Field Ion Microscope

The field ion microscope, devised by Erwin Muller in the 1950's, was the first instrument to depict the structure of surfaces in atomic detail. An FIM image of a (111) plane of tungsten (Fig.l) is typical of what can be done by this microscope: for this small plane, every atom, at a separation of 4.48Å from its neighbors in the plane, is revealed. The image of the plane is highly enlarged, as it is projected on a phosphor screen with a radius of curvature more than a million times that of the sample. Müller achieved the resolution necessary to reveal individual atoms by imaging with ions, accommodated to the object at a low temperature. The ions are created at the sample surface by ionization of an inert image gas (usually helium), present at a low pressure (< 1 mTorr). at fields on the order of 4V/Å.

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