Very high temperature, moderate pressure metamorphism in the New Russia gneiss complex, northeastern Adirondack Highlands, metamorphic aureole to the Marcy anorthosite

1999 ◽  
Vol 36 (1) ◽  
pp. 1-13 ◽  
Author(s):  
J Alcock ◽  
Peter Muller

The New Russia gneiss complex in the northeastern Adirondack Highlands of New York includes meta-anorthosite gneiss and anatectic gneiss derived from metagabbro, mangerite, and charnockite. Metamorphic conditions during anatexis (850-950°C, highest near the anorthosite, with pressure ~750 MPa) are inferred from minerals and textures produced by dehydration melting of pargasitic hornblende and from ternary feldspar in anatectic segregations. The complex abuts and is crosscut by the eastern margin of the ~1130 Ma Marcy anorthosite massif. The crosscutting contact, the presence of meta-anorthosite gneiss within the complex and undeformed meta-anorthosite in the massif, and the occurrence of deformed and undeformed anatectic segregations within the New Russia gneisses indicate an approximate synchroneity of penetrative deformation, very high temperature metamorphism, and emplacement of anorthosite with both intrusion and anatexis outlasting deformation. The position of the New Russia gneisses, the metamorphic gradient within them, and the contemporaneity of anatexis with intrusion of anorthosite imply that the complex is the metamorphic aureole of the Marcy anorthosite.

Author(s):  
P. E. Batson ◽  
C. H. Chen ◽  
J. Silcox

Electron energy loss experiments combined with microscopy have proven to be a valuable tool for the exploration of the structure of electronic excitations in materials. These types of excitations, however, are difficult to measure because of their small intensity. In a usual situation, the filament of the microscope is run at a very high temperature in order to present as much intensity as possible at the specimen. This results in a degradation of the ultimate energy resolution of the instrument due to thermal broadening of the electron beam.We report here observations and measurements on a new LaB filament in a microscope-velocity spectrometer system. We have found that, in general, we may retain a good energy resolution with intensities comparable to or greater than those available with the very high temperature tungsten filament. We have also explored the energy distribution of this filament.


Author(s):  
Gerald B. Feldewerth

In recent years an increasing emphasis has been placed on the study of high temperature intermetallic compounds for possible aerospace applications. One group of interest is the B2 aiuminides. This group of intermetaliics has a very high melting temperature, good high temperature, and excellent specific strength. These qualities make it a candidate for applications such as turbine engines. The B2 aiuminides exist over a wide range of compositions and also have a large solubility for third element substitutional additions, which may allow alloying additions to overcome their major drawback, their brittle nature.One B2 aluminide currently being studied is cobalt aluminide. Optical microscopy of CoAl alloys produced at the University of Missouri-Rolla showed a dramatic decrease in the grain size which affects the yield strength and flow stress of long range ordered alloys, and a change in the grain shape with the addition of 0.5 % boron.


Alloy Digest ◽  
2005 ◽  
Vol 54 (12) ◽  

Abstract Wieland K-88 is a copper alloy with very high electrical and thermal conductivity, good strength, and excellent stress relaxation resistance at elevated temperatures. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. It also includes information on high temperature performance and corrosion resistance as well as forming, heat treating, machining, joining, and surface treatment. Filing Code: CU-738. Producer or source: Wieland Metals Inc.


Alloy Digest ◽  
2008 ◽  
Vol 57 (6) ◽  

Abstract Kubota UCX was developed for very high temperature operation for ethylene pyrolysis service. The alloy also has excellent oxidation and corrosion resistance. This datasheet provides information on composition, physical properties, elasticity, and tensile properties. It also includes information on high temperature performance and corrosion resistance as well as casting and joining. Filing Code: Ni-663. Producer or source: Kubota Metal Corporation, Fahramet Division.


Sign in / Sign up

Export Citation Format

Share Document