scholarly journals Tungsten in the Godthåb area, West Greenland

1983 ◽  
Vol 115 ◽  
pp. 59-63
Author(s):  
P.W.U Appel
Keyword(s):  
Ultra Violet ◽  
Heavy Mineral ◽  
Field Observations ◽  
X Ray ◽  
West Greenland ◽  
Ultra Violet Light ◽  
Violet Light ◽  
Tungsten Mineral ◽  
A Minor ◽  
Minor Difficulty

The tungsten mineral scheelite has not previously been reported from the Godthåb area in West Greenland. The first indications of its presence were found in heavy mineral concentrates from a stream on Storø in Godthåbsfjord. Exploration for scheelite in Greenland is difficult. A systematic stream-sediment programme cannot be undertaken before mid-June because many of the streams are frozen or covered with snow until then. Examination in ultra-violet light must be carried out in darkness so scheelite cannot be looked for before the end of August because of the midnight sun and the work must be finished by early September when snow covers the ground. A minor difficulty in this context is the abundance of lichens with bluish white fluorescence which cover the rock surfaces. The following report is based on field observations only. Laboratory work was limited to X-ray identification ofscheelite in two heavy mineral concentrates and in two rock samples.

scholarly journals On the occurrence of scheelite in the Archaean Malene supracrustal rocks, southern West Greenland

1986 ◽  
Vol 130 ◽  
pp. 52-57
Author(s):  
P.W.U Appel ◽  
A A Garde
Keyword(s):  
Ultra Violet ◽  
Stream Sediments ◽  
Laboratory Work ◽  
Field Observations ◽  
Thin Sections ◽  
X Ray ◽  
Ultra Violet Light ◽  
Violet Light ◽  
Similar Survey

Scheelite in the Godthåbsfjord area (fig. 1) was found in heavy mineral concentrates from stream sediments in 1982, and in situ scheelite was discovered in 1982 on Storø in Godthåbsfjord (Appel, 1983a). During 1983 further work was carried out on the islands of Storø and Sermitsiaq in Godthåbsfjord and on the Store Malene mountain next to Nuuk (Godthåb), as aresult of which several scheelite-bearing horizons were found (Appel, 1984). During 1985 a detailed mapping programme was carried out on Store Malene by A. A. Garde. Subsequently, exposures on Store Malene as well as the island of Simiutat south of Nuuk were investigated by ultra-violet light. A similar survey has oeen carried out by Olsen (this volume) on the island of Sermitsiaq. Thc folIowing report is mainly based on field observations combined with investigation of a few thin sections. Laboratory work has been confined to X-ray identification of scheelite in four samples from Store Malene and one sample from Simiútat.

scholarly journals On the excitation of characteristic X-rays from light elements

1923 ◽  
Vol 102 (717) ◽  
pp. 389-410 ◽  
Keyword(s):  
Ultra Violet ◽  
Critical Values ◽  
X Rays ◽  
Light Elements ◽  
X Ray ◽  
Ultra Violet Light ◽  
Violet Light ◽  
Light Waves ◽  
Electric Effect ◽  
Electric Action

In an attempt to fill up the gap between the shortest ultra-violet light waves hitherto produced and the longest X-ray waves known, Hughes recently made a study of the characteristic X-rays emitted by carbon and by boron when bombarded by electrons. In this investigation the energy of the bombarding electrons was increased by steps, and the critical values were determined that were necessary and just sufficient to cause the bombarded element to emit its characteristic radiations with measurable intensities. These characteristic radiations were detected, and their intensities measured, by their photo-electric action on an insulated electrode of nickel or of silver. The method followed by Hughes in recording his results was to plot curves with the values of the accelerating potentials of the electrons as abscissæ and the measures of the photo-electric effect divided by the corresponding electronic currents as ordinates. At certain critical accelerating voltages it was found that these curves showed marked and abrupt kinks or changes of curvature, and these changes were taken to connote the beginning of the emission by the bombarded element of its characteristic radiations.

scholarly journals Tungsten mineralisation in Archaean supracrustal rocks at Sermitsiaq, southern West Greenland

1986 ◽  
Vol 130 ◽  
pp. 60-63
Author(s):  
H.K Olsen
Keyword(s):  
Special Reference ◽  
Ultra Violet ◽  
Field Work ◽  
Aerial Photographs ◽  
Field Observations ◽  
X Ray ◽  
West Greenland ◽  
Rock Samples ◽  
Geological Map

The purpose of the field work was detailed mapping of the eastern part of the island Sermitsiaq in outer Godthåbsfjord, with special reference to its tungsten mineralisation (Appel, 1983). During six weeks in the summer of 1985 a geological map was made using enlarged aerial photographs at scale 1:10 000, and scheelite showings were localised with ultra-violet lamps at night (fig. 1). Thefollowing report is based on field observations and X-ray determination of scheelite in four rock samples.

scholarly journals Tungsten mineralisation in the Godthåb area, West Greenland

1984 ◽  
Vol 120 ◽  
pp. 51-54
Author(s):  
P.W.U Appel
Keyword(s):  
Ultra Violet ◽  
Field Work ◽  
Stream Sediments ◽  
Field Observations ◽  
X Ray ◽  
Violet Light ◽  
Sediment Sampling ◽  
Sampling Programme ◽  
Inner Parts

The discovery in 1982 of scheelite in stream sediments in the Godthåb area and in situ mineralisations in the early Archaean Akilia rocks on Storø in Godthåbsfjord (Appel, 1983) was followed up by field work in the summer of 1983. The regional stream sediment sampling programme was extended to Ameralik fjord, south af Godthåb, and to the inner parts of Godthåbsfjord. Field work at night with ultra-violet light examination was carried out on Storø and Sadelø in Godthåbsfjord and in Kobbefjord, south of Godthåb. The latter part of the programme was carried out with the assistance of volunteers from Ungdomstjenesten (Greenland's Youth Organisation). The folIowing report is based on field observations only. Laboratory work has been Iimited to X-ray identification of scheelite in four rock samples; two from Storø, one from Sadelø and one from Kobbefjord.

XXII.—Deficiency Effects of Ultra-violet Light in Drosophila melanogaster

1942 ◽  
Vol 61 (3) ◽  
pp. 297-315
Author(s):  
B. M. Slizynski
Keyword(s):  
Drosophila Melanogaster ◽  
Ultra Violet ◽  
Maize Pollen ◽  
X Ray ◽  
Ultra Violet Light ◽  
Violet Light ◽  
Ultra Violet Radiation ◽  
Chromosomal Changes ◽  
Ray Series ◽  
Violet Radiation

Stadler and Sprague in a series of papers (1936) succeeded in demonstrating by a genetical method the effect of ultra-violet radiation in maize pollen, and found that in their experiments in the X-ray series the chromosomal changes are very common, while in the ultra-violet series they are rare.

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