Fluid inclusions in charnockites from Kodaikanal massif (South India): P-T record and implications for crustal uplift history

1996 ◽  
Vol 57 (3-4) ◽  
pp. 167-184 ◽  
Author(s):  
A. Mohan ◽  
D. Prakash ◽  
H. K. Sachan
Keyword(s):  
Fluid Inclusions ◽  
South India ◽  
Crustal Uplift ◽  
Uplift History

Paleomagnetism of dykes from the Groundhog River Block, northern Ontario: implications for the uplift history of the Kapuskasing Structural Zone

1991 ◽  
Vol 28 (9) ◽  
pp. 1424-1428 ◽  
Author(s):  
M. P. Bates ◽  
H. C. Halls
Keyword(s):  
Superior Province ◽  
High Grade ◽  
Northern Ontario ◽  
Central Segment ◽  
History Of ◽  
Crustal Uplift ◽  
Uplift History ◽  
Host Rocks

The groundhog River Block (GB) forms the central segment of the Kapuskasing Structural Zone a fault-bounded belt of Proterozoic crustal uplift in the southern Superior Province. Dykes adjacent to the GB carry a magnetization (D = 11°, I = 26°, α95 = 27°, N = 3) that is characteristic of 2.45 Ga Matachewan dykes. However, within the GB, dykes and high-grade gneissic host rocks carry a steep positive magnetization (D = 295°, I = 83°, α95 = 12°, N = 9) that also partially overprints the dykes immediately outside the GB. The boundaries between the contrasting paleomagnetic signatures coincide with boundary faults and changes in paleopressure that define the GB. The steep magnetization in the GB was acquired during uplift and cooling close to the time at about 1.95 Ga when a virtually antiparallel remanence of similar origin was being formed in the Chapleau Block, the southern segment of the Kapuskasing Structural Zone.

Characterization of submicrometer fluid Inclusions in minerals by Analytical/Transmission Electron Microscopy and electron diffraction

1990 ◽  
Vol 48 (4) ◽  
pp. 424-424
Author(s):  
George Guthrie ◽  
David Veblen
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Electron Microscope ◽  
Electron Diffraction ◽  
Light Microscopy ◽  
Fluid Inclusions ◽  
Energy Dispersive Spectrometer ◽  
Analytical Transmission Electron Microscopy ◽  
Transmission Electron

The nature of a geologic fluid can often be inferred from fluid-filled cavities (generally <100 μm in size) that are trapped during the growth of a mineral. A variety of techniques enables the fluids and daughter crystals (any solid precipitated from the trapped fluid) to be identified from cavities greater than a few micrometers. Many minerals, however, contain fluid inclusions smaller than a micrometer. Though inclusions this small are difficult or impossible to study by conventional techniques, they are ideally suited for study by analytical/ transmission electron microscopy (A/TEM) and electron diffraction. We have used this technique to study fluid inclusions and daughter crystals in diamond and feldspar.Inclusion-rich samples of diamond and feldspar were ion-thinned to electron transparency and examined with a Philips 420T electron microscope (120 keV) equipped with an EDAX beryllium-windowed energy dispersive spectrometer. Thin edges of the sample were perforated in areas that appeared in light microscopy to be populated densely with inclusions. In a few cases, the perforations were bound polygonal sides to which crystals (structurally and compositionally different from the host mineral) were attached (Figure 1).

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